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1
Content available Assignability of numerical characteristics of time-varying systems
Babiarz A., Czornik A., Klamka J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2019
|
Vol. 67, nr 6
1007--1022
EN
The main aim of this article is to survey and discuss the existing state of art concerning the assignability by a feedback of numerical characteristics of linear continuous and discrete time-varying systems. Most of the results present necessary or sufficient conditions for different formulation of the Lyapunov spectrum assignability problem. These conditions are expressed in terms of various controllability types and optimalizability of the controlled systems and certain properties of the free system such as: regularity, diagonalizability, boundness away, integral separation and reducibility.
2
Historia rozwoju przyrządów półprzewodnikowych w Polsce stosowanych w praktyce (cz. I)
Klamka J.
Przegląd Techniczny : Gazeta Inżynierska
|
2017
|
nr 18
18--20
PL
W artykule przedstawiono historię kolejnych opracowań i wprowadzenia do zastosowań praktycznych pierwszych polskich przyrządów półprzewodnikowych w latach 1964-2000. Są to germanowe i krzemowe diody prostownicze, fotodiody, diody Zenera i przyrządy mikrofalowe dla uzbrojenia radioelektronicznego, głównie dla radiolokacji (waraktory, diody ładunkowe, diody i generatory Gunna, diody PIN, tranzystory).
EN
Article describes history of successive studies and introduction to practical applications of first Polish semi-conductor devices in the period of 1964-2000. They are germanous and siliceous rectifying diodes, photodiodes, Zener diodes and microwave devices for radioelectronic weaponry mainly for radiolocation (varactors, charge storage diodes, Gunna diodes and generators, PIN diodes, Schottky diodes, transistors).
3
Historia rozwoju przyrządów półprzewodnikowych w Polsce stosowanych w praktyce (cz. II)
Klamka J.
Przegląd Techniczny : Gazeta Inżynierska
|
2017
|
nr 19-20
19--22
PL
W artykule przedstawiono historię kolejnych opracowań i wprowadzenia do zastosowań praktycznych pierwszych polskich przyrządów półprzewodnikowych w latach 1954-2000. Są to germanowe i krzemowe diody prostownicze, fotodiody, diody Zenera i przyrządy mikrofalowe dla uzbrojenia radioelektronicznego, głównie dla radiolokacji (waraktory, diody ładunkowe, diody Schottky’ego, diody i generatory Gunna, diody PIN, tranzystory).
EN
Article describes history of successive studies and introduction to practical applications of first Polish semiconductor devices in the period of 1954-2000. They are german and silicon rectifying diodes, photodiodes, Zener diodes and microwave devices for radioelectronic military egwiment mailny for radiolocation (varactors, charge storage diodes, Schottky diodes, Gunna diodes and generators, PIN diodes, transistors).
4
Content available On controllability of second order dynamical systems – a survey
Klamka J., Wyrwał J., Zawiski R.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2017
|
Vol. 65, nr 3
279--295
EN
The paper presents a survey of recent results in the area of controllability of second order dynamical systems. Controllability problem for finite and infinite dimensional, linear, semilinear, deterministic and stochastic dynamical systems (with delays and undelayed) is taken into consideration. Different types of controllability are discussed.
5
Content available The use of a non-integer order PI controller with an active queue management mechanism
Domański A., Domańska J., Czachórski T., Klamka J.
International Journal of Applied Mathematics and Computer Science
|
2016
|
Vol. 26, no. 4
777--789
EN
In this paper the performance of a fractional order PI controller is compared with that of RED, a well-known active queue management (AQM) mechanism. The article uses fluid flow approximation and discrete-event simulation to investigate the influence of the AQM policy on the packet loss probability, the queue length and its variability. The impact of self-similar traffic is also considered.
6
Content available Schauder’s fixed-point theorem in approximate controllability problems
Babiarz A., Klamka J., Niezabitowski M.
International Journal of Applied Mathematics and Computer Science
|
2016
|
Vol. 26, no. 2
263--275
EN
The main objective of this article is to present the state of the art concerning approximate controllability of dynamic systems in infinite-dimensional spaces. The presented investigation focuses on obtaining sufficient conditions for approximate controllability of various types of dynamic systems using Schauder’s fixed-point theorem. We describe the results of approximate controllability for nonlinear impulsive neutral fuzzy stochastic differential equations with nonlocal conditions, impulsive neutral functional evolution integro-differential systems, stochastic impulsive systems with control-dependent coefficients, nonlinear impulsive differential systems, and evolution systems with nonlocal conditions and semilinear evolution equation.
7
Content available Banach fixed-point theorem in semilinear controllability problems – a survey
Klamka J., Babiarz A., Niezabitowski M.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2016
|
Vol. 64, nr 1
21--35
EN
The main aim of this article is to review the existing state of art concerning the complete controllability of semilinear dynamical systems. The study focus on obtaining the sufficient conditions for the complete controllability for various systems using the Banach fixedpoint theorem. We describe the results for stochastic semilinear functional integro-differential system, stochastic partial differential equations with finite delays, semilinear functional equations, a stochastic semilinear system, a impulsive stochastic integro-differential system, semilinear stochastic impulsive systems, an impulsive neutral functional evolution integro-differential system and a nonlinear stochastic neutral impulsive system. Finally, two examples are presented.
8
Content available The selected problems of controllability of discrete-time switched linear systems with constrained switching rule
Babiarz A., Czornik A., Klamka J., Niezabitowski M.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2015
|
Vol. 63, nr 3
657--666
EN
In this paper the controllability problem for discrete-time linear switched systems is considered. The main goal is to find a control signal that steers any initial state to a given final state independently of the switching signal. In the paper, it is assumed that there are some constraints posed on the switching signal. Moreover, we present a necessary and sufficient conditions of some kinds of controllability. Three types of controllability, namely: from zero initial state to any final state, from any initial state to zero final state and from any initial state to any final state are considered. Finally, three illustrative examples are shown.
9
Content available A RED modified weighted moving average for soft real-time application
Domańska J., Domański A., Augustyn D. R., Klamka J.
International Journal of Applied Mathematics and Computer Science
|
2014
|
Vol. 24, no. 3
697--707
EN
The popularity of TCP/IP has resulted in an increase in usage of best-effort networks for real-time communication. Much effort has been spent to ensure quality of service for soft real-time traffic over IP networks. The Internet Engineering Task Force has proposed some architecture components, such as Active Queue Management (AQM). The paper investigates the influence of the weighted moving average on packet waiting time reduction for an AQM mechanism: the RED algorithm. The proposed method for computing the average queue length is based on a difference equation (a recursive equation). Depending on a particular optimality criterion, proper parameters of the modified weighted moving average function can be chosen. This change will allow reducing the number of violations of timing constraints and better use of this mechanism for soft real-time transmissions. The optimization problem is solved through simulations performed in OMNeT++ and later verified experimentally on a Linux implementation.
10
60-lecie pracy na rzecz rozwoju elektroniki półprzewodnikowej w Polsce : wspomnienia
Klamka J.
Elektronika : konstrukcje, technologie, zastosowania
|
2014
|
Vol. 55, nr 1
44-50
PL
W artykule przedstawiono historię pierwszych polskich urządzeń półprzewodnikowych opracowanych i wytwarzanych przez Autora i jego współpracowników.
EN
In this paper the history of first Polish semiconductor devices is presented.
11
Content available Fluid flow approximation of time-limited TCP/UDP/XCP streams
Domańska J., Domański A., Czachórski T., Klamka J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2014
|
Vol. 62, nr 2
217--225
EN
This article presents the use of fluid flow approximation to model interactions between a set of TCP, UDP and XCP flows in the environment of IP routers using AQM (Active Queue Management) algorithms to control traffic congestion. In contrast to other works, independent UDP and TCP streams are considered and the model allows to start and end data transmissions in TCP, UDP and XCP streams at any time moment. It incorporates several Active Queue Management mechanisms: RED, NLRED, CHOKe.
12
Content available Analysis of CHOKe - family active queue management
Domański A., Domańska J., Klamka J.
Theoretical and Applied Informatics
|
2013
|
Vol. 25, No. 1
49--66
EN
In the article we study a model of network transmissions with Active Queue Management in an intermediate IP router. We use the OMNET++ discrete event simulator to model the varies variants of the CHOKe algoithms. We model a system where CHOKe, xCHOKe and gCHOKe are the AQM policy. The obtained results shows the behaviour of these algorithms. The paper presents also the implementation of AQM mechanisms in the router based on Linux.
PL
W artykule został przedstawiony model sieciowej transmisji danych poprzez router z zaimplementowanymi mechanizmami Aktywnego Zarządzania Kolejką (AQM). Badania zachowania mechanizmów AQM zostały przeprowadzone przy użyciu symulatora zdarzeń dyskretnych OMNET++. Uzyskane wyniki zostały zweryfikowane w środowisku rzeczywistym. W oparciu o system operacyjny Linux stworzono programowy router implementujący mechanizmy wcześniej przebadane w środowisku symulacyjnym. Przeprowadzono analizę zachowania algorytmów AQM z rodziny CHOKe (CHOKe, xCHOKe, gCHOKe). W badaniach rozważano problem wpływu tych mechanizmów na tzw. agresywne (potrzebujące większego pasma) źródła transmisji danych.
13
Content available Controllability of a model of combined anticancer therapy
Klamka J., Świerniak A.
Control and Cybernetics
|
2013
|
Vol. 42, no. 1
123--138
EN
Controllability of combination of antiangiogenic treatment and chemotherapy is considered. A model used in the paper is a finite-dimensional dynamical control system described by secondo order semilinear time invariant ordinary differential state equations. Using a generalized open mapping theorem, sufficient conditions for constrained local controllability in a given time interval are formulated and proved. These conditions require verification of constrained global controllability of the associated linear second-order dynamical control system.
14
Content available Constrained controllability of second order dynami cal systems with delay
Klamka J.
Control and Cybernetics
|
2013
|
Vol. 42, no. 1
111--121
EN
The paper considers finite-dimensional dynami cal control systems described by second order semilinear stationary ordinary differential state equations with delay in control. Using a generalized open mapping theorem, sufficient conditions for constrained local controllability in a given time interval are formulated and proved. These conditions require verification of constrained global controllability of the associated linear first-order dynamical control system. It is generally assumed that the values of admissible controls are in a convex and closed cone with vertex at zero. Moreover, several remarks and comments on the existing results for controllability of semilinear dynamical control systems are also presented. Finally, a simple numerical example which illustrates theoretical considerations is also given. It should be pointed out that the results given in the paper extend for the case of semilinear second-order dynamical systems constrained controllability conditions, which were previously known only for linear second-order systems.
15
Content available The dynamics of the human arm with an observer for the capture of body motion parameters
Babiarz A., Bieda R., Jaskot K., Klamka J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2013
|
Vol. 61, nr 4
955--971
EN
The paper presents an analysis of a mathematical model of the human arm dynamics in terms of observability. The purpose of the performed experiments is the selection of an observer for the possibility of arm tracking. The arm model is based on the two-link manipulator moving horizontally and vertically. For the study a model was linearized and the model part responsible for the work of human muscles was omitted. The experimental part involved simulated measurements of the motion parameters that imitate real-IMU (Inertial Measurement Unit) measurements. Finally, the simulation results using the observer in the form of a Kalman filter and the particle filter have been presented.
16
Content available Stability criteria for a class of stochastic distributed delay systems
Ficak B., Klamka J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2013
|
Vol. 61, nr 1
221-228
EN
In the paper linear distributed delay stochastic systems are considered. Using theory of stochastic differential equations sufficient conditions for different kinds of stability are formulated and proved. The article attempts to generalise results presented in the paper [1] and thus theorems proved in [1] become a special case of a generalised approach. The considered class is wider - the function that influence dynamics of a problem can be a real solution of N-degree linear deterministic differential equation. Therefore the generalised reduction technique of distributed delay to lumped delay has to be applied. Criteria for numerous properties of the aforementioned class followed Mao theory designed for point delay systems [2, 3].
17
Content available Stability and controllability of switched systems
Klamka J., Czornik A., Niezabitowski M.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2013
|
Vol. 61, nr 3
547--555
EN
The study of properties of switched and hybrid systems gives rise to a number of interesting and challenging mathematical problems. This paper aims to briefly survey recent results on stability and controllability of switched linear systems. First, the stability analysis for switched systems is reviewed. We focus on the stability analysis for switched linear systems under arbitrary switching, and we highlight necessary and sufficient conditions for asymptotic stability. After that, we review the controllability results.
18
Content available Controllability of dynamical systems. A survey
Klamka J.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2013
|
Vol. 61, nr 2
335--342
EN
The main objective of this article is to review the major progress that has been made on controllability of dynamical systems over the past number of years. Controllability is one of the fundamental concepts in the mathematical control theory. This is a qualitative property of dynamical control systems and is of particular importance in control theory. A systematic study of controllability was started at the beginning of sixties in the last century, when the theory of controllability based on the description in the form of state space for both time-invariant and time-varying linear control systems was worked out. Roughly speaking, controllability generally means, that it is possible to steer a dynamical control system from an arbitrary initial state to an arbitrary final state using the set of admissible controls. It should be mentioned, that in the literature there are many different definitions of controllability, which strongly depend on a class of dynamical control systems and on the other hand on the form of admissible controls. Controllability problems for different types of dynamical systems require the application of numerous mathematical concepts and methods taken directly from differential geometry, functional analysis, topology, matrix analysis and theory of ordinary and partial differential equations and theory of difference equations. In the paper we use mainly state-space models of dynamical systems, which provide a robust and universal method for studying controllability of various classes of systems. Controllability plays an essential role in the development of modern mathematical control theory. There are various important relationships between controllability, stability and stabilizability of linear both finite-dimensional and infinite-dimensional control systems. Controllability is also strongly related to the theory of realization and so called minimal realization and canonical forms for linear time-invariant control systems such as the Kalmam canonical form, the Jordan canonical form or the Luenberger canonical form. It should be mentioned, that for many dynamical systems there exists a formal duality between the concepts of controllability and observability. Moreover, controllability is strongly connected with the minimum energy control problem for many classes of linear finite dimensional, infinite dimensional dynamical systems, and delayed systems both deterministic and stochastic. Finally, it is well known, that controllability concept has many important applications not only in control theory and systems theory, but also in such areas as industrial and chemical process control, reactor control, control of electric bulk power systems, aerospce engineering and recently in quantum systems theory.
19
Content available Examination of robust D - stability of TCP - DCR protocol
Klamka J., Tańcula J.
Theoretical and Applied Informatics
|
2012
|
Vol. 24, No. 4
327-344
EN
This paper presents non-linear mathematical model of a computer network with a part of wireless network. The article contains an analysis of the stability of the network based on TCP-DCR, which is a modification of the traditional TCP. Block diagram of the network model was converted to a form in order to investigate the D-stability using the method of the space of uncertain parameters. Robust D-stability is calculated for constant delays values.
PL
W pracy przedstawiono nieliniowy model matematyczny sieci komputerowej w postaci układu dwóch równań różniczkowych ze skupionym zmiennym w czasie opóźnieniem we współrzędnych stanu. Przedstawiono model w postaci schematu blokowego, a następnie dokonano przekształceń schematu zgodnie z linearyzacją równań. Wydajność aplikacji w dużym stopniu zależy od stosowanego w sieci algorytmu zarządzania kolejką. Aktywne zarządzanie kolejką (Active Queue Management) w rozpatrywanym modelu sieci komputerowej polega na zastosowaniu algorytmu RED (Random Early Detection) w sprzężeniu zwrotnym. Jeśli przyjąć, że sieć komputerowa jest specyficznym układem dynamicznym to możemy poddać badaniu stabilnści taki układ. Analityczne metody badania D-stabilności mogą być trudne do sprawdzenia, dlatego w niniejszej pracy zaproponowano metody graficzne znane z literatury. Przedstawiono również przykłady liczbowe badania stabilności dla rzeczywistej sieci komputerowej. Wykorzystano metodę częstotliwościową oraz metodę przestrzeni niepewnych parametrów quasi-wielomianów, która jest rozwinięciem klasycznej metody podziału D. Polega ona na wyznaczeniu w przestrzeni niepewnych parametrów quasi-wielomianów zbioru takich wartósci niepewnych parametrów, dla których jest on asymptotycznie stabilny. Przy użyciu tej metody określono granice obszaru odpornej D-stabilności. Wyznaczenie granic stabilności układu pozwoli zaprojektować sieć bezprzewodową bardziej wydajną, szybszą i odporną na błędy.
20
Analiza D-stabilności protokołu TCP-DCR
Klamka J., Tańcula J.
Studia Informatica
|
2012
|
Vol. 33, nr 3A
7-18
PL
Praca zawiera analizę stabilności sieci na podstawie protokołu TCPDCR, będącego modyfikacją tradycyjnego TCP. Utworzono model matematyczny sieci i opisano go równaniami. Schemat blokowy modelu sieci przekształcono do takiej postaci, aby zbadać jego D-stabilnośe stosując metodę przestrzeni niepewnych parametrów.
EN
The paper contains an analysis of the stability of the netwofk based on TCP-DCR, which is a modification of the traditional TCP. Created inatheoiatical model of the network and it is described by equatioas. Błock diagram of the nerwork niodel was converted to a form in order to investigałe the D-stability using tlie niethod of the space of imcertain parameters.
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