Wyniki wyszukiwania - Biblioteka Nauki

1

Synchronization of a line of identical processors at a given time

100%

La Torre S. , Napoli M. , Parente D.

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tom Vol.34, nr 1,2

103-128

EN

We are given a line of n identical processors (finite automata) that work synchronously. Each processor can transmit just one bit of information to the adjacent processor (if any) to the left and to the right. The computation starts at time 1 with the leftmost processor in an initial atate and all other processors in a quiescent state. Given the time f(n), the problem is to set (synchronize) all the processors in a particular state for the first time, at the very same instant f(n). This problem is also known as the Firing Squad Synchronization Problem and was introduced by Moore in 1964. Mazoyer has given a minimal time solution with the least number of different states (six) and very recently he has given a minimal time solution for the constrained problem in which adjacent processors can exchange only one bit. In this paper we present solutions that synchronize the line a given time, expressed as a function of n. In particular we give solutions that synchronize at the times n log n, nÖn, n2 and 2n. Moreover we also show how to compose solutions in such a way to obtain synchronizing solutions for all times expressed by polynomials with nonnegative coefficients. Clearly all such solutions work also in the general case when the bit constraint is relaxed.

2

Opracowania ZST dotyczące systemów SDH, ich synchronizacji i zarządzania

80%

Dąbrowski A. , Brożyna J. , Drobnik A. , Kula S.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2010

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tom nr 4

117-117

PL

Omówiono najważniejsze prace dotyczące systemów teletransmisyjnych SDH oraz ich synchronizacji prowadzone w Zakładzie Systemów Teletransmisyjnych w latach 1993-2000.

EN

This article describes shortly most important works done at Transmission System Division on SDH systems and their synchronization within the period 1993-2000.

3

Łagodzenie oraz skrócenie czasu procesu synchronizacji silników synchronicznych

80%

Zalas P. , Zawilak J.

Elektrotechnika i Elektronika

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2006

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tom T. 25, z. 2

216-220

PL

Przedstawiono wyniki obliczeń procesu synchronizacji dla wybranego modelu dwubiegowego silnika synchronicznego typu GAe 1716/20t. Wykazano możliwości łagodzenia przebiegu procesu synchronizacji oraz skrócenia jego czasu przez sterowanie wartością prądu wzbudzenia. Zbadano wpływ przyjętych układów regulacji prądu magneśnicy na przebiegi tego procesu. Wyniki obliczeń zamieszczono w postaci wykresów czasowych.

EN

The work presents calculation results of synchronization process of a two-speed, silent-pole, high power synchronous motor. The calculations were based on circuit model for motor type GAe 1716/20t with switchable configuration connection of armature winding and field magnet. The influence of control of excitation current value on stator currents, electromagnetic torque and shaft velocity during synchronization process has been investigated. The results of calculations were presented as time curves of state variables.

4

Two-Plane Automatic Balancing

80%

Sperling L. , Ryzhik B. , Duckstein H.

Machine Dynamics Problems

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2001

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tom Vol. 25, No. 3/4

139-152

EN

A theory of two-plane automatic balancing of rigid rotors is presented. For a rotor with two pairs of compensation balls or rollers the stability of compensation phasing is analysed by employing the method of direct separation of motion. The results are confirmed by computer simulation based on the complete equations of motion linearised in the vibrational co-ordinates.

5

Synchronization of two forced double-well Duffing oscillators with attached pendulums

80%

Brzeski P. , Karmazyn A. , Perlikowski P.

Journal of Theoretical and Applied Mechanics

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2013

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tom Vol. 51 nr 3

603--613

EN

We investigate the dynamics of two coupled Duffing oscillators with attached pendulums forced kinematically by a common signal. Our attention is focused on different kinds of synchronization which can appear in the considered system. Different types of coupling (spring, damper and spring and damper simultaneously) are taken into account. We show in a two-parameters space (amplitude and frequency of excitation) existence of complete and phase synchronization and asynchronous ranges.

6

Algorytm rekonstrukcjimapy rozkladu temperatury na powierzchni obracającego walca ze strumienia video kamery termowizyjnej

80%

Jaworski T. , Kucharski J.

Zeszyty Naukowe. Elektryka / Politechnika Łódzka

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2012

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tom z. 124

149-158

PL

W artykule przedstawiono algorytm opracowany w celu rekonstrukcji pełnej mapy rozkładu temperatury na powierzchni obracającego się stalowego walca nagrzewanego indukcyjne. Zródłem danych dla algorytmu jest strumień wideo pochodzący z kamery termowizyjnej. Uwzględniona została geometria obiektu i konieczność synchronizacji wykonywanych pomiarów względem aktualnego położenia kątowego walca. Ostatecznie, z serii zsynchronizowanych pomiarów rekonstruowany jest rozkład dla całej powierzchni walca.

EN

The following paper presents an algorithm developed to reconstruct a full temperature distribution map of a rotating steel roller's surface. The surface is constantly monitored by an IR camera that produces a stream of frames. Frame acquisition is triggered by a set of equidistant angles used by electronic synchronization module. Received stream is divided into blocks with equal number of frames in each and for every valid block a reconstruction algorithm is executed. Finally, a full temperature map for entire circumference of the cylinder is obtained.

7

On synchronization in P systems

80%

Paun G. , Yu S.

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1999

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tom Vol. 38, Nr 4

397-410

EN

The P systems were recently introduced as distributed parallel computing models of a biochemical type. Multisets of objects are placed in a hierarchical structure of membranes and they evolve according to given rules, which are applied in a synchronous manner: at each step, all objects which can evolve, from all membranes, must evolve. We consider here the case when this restriction is removed. As expected, unsynchronized systems (even using catalysts) are weaker than the synchronized ones, providing that no priority relation among rules is considered. The power of P systems is not diminished when a priority is used and, moreover, the catalysts can change their states, among two possible states for each catalyst.

8

Methods of reducing the number of synchronization messages for event-driven simulation

80%

Nowak M.

Theoretical and Applied Informatics

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2006

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tom Vol. 18, nr 3

189-199

EN

he aiticle proposes a new synchronization algorithm for distributed event-driven simulation. New solution is based on Time Waip algorithm. It aims at reducing the number of messages sent through ihe nctwork to synchromze simulation nodes. The simulator in which the new algonthm was implemented is shortly shown, too.

PL

Artykuł przedstawia algorytm synchronizacji dla rozproszonej symulacji sterowanej zdarzeniami. Jest on oparty o algorytm Time Warp [9], zaliczany do grupy optymistycznych algorytmów synchronizacji. Przedstawiony algorytm ma na celu zmniejszenie liczby komunikatów administracyjnych wysyłanych przez węzeł obliczeniowy biorący udział w symulacji. Wprowadzono dodatkowe (w stosunku do Time Warp) założenia dotyczące kolejności wysyłania i otrzymywania komunikatów w chwili, kiedy wykonywana jest synchronizacja i węzeł, na którym wystąpiło złamanie ograniczeń przyczynowości wycofuje swoją synchronizację. Dzięki temu w miejsce chmury tzw. antykomunikatów wysyłanych przez węzeł działający zgodnie z dotychczasową metodą wystarczy wysłać pojedynczy komunikat administracyjny informujący o wycofaniu symulacji. Uzyskane wyniki potwierdziły, że (zgodnie z przewidywaniami) obsługa pojedynczego komunikatu okazała się szybsza niż chmury antykomunikatów, co pozwoliło na skrócenie operacji synchronizacji. Artykuł przedstawia również krótko symulator dsim, w którym zastosowano opisaną metodę synchronizacji.

9

Spectral analysis of business cycles in Poland and its major trading partners

80%

KIJEK A.

Operations Research and Decisions

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2017

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tom 27

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nr 1

57-75

EN

The properties of business cycles in Poland and its major trading partners have been examined. The business cycle synchronization (BCS) between Poland and other countries was studied in order to assess the impact of international trade on BCS. The author applies a modification of the Fourier anal-ysis to the estimation of cycle amplitudes and frequencies. This allows more precise estimation of the cycle characteristics than the traditional approach. Cross-spectral analysis of the cyclical components of GDP for Poland and its major trading partners enables us to study the relationships between business cycles in these countries. Comparing the international structure of Polish trade with that of EU members with the cross-spectral characteristics of GDP series allows us to investigate the links between interna-tional trade and business cycle synchronization.

10

A new 4-D dynamical system exhibiting chaos with a line of rest points, its synchronizationand circuit model

80%

Vaidyanathan S. , Sambas A. , Zhang S.

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tom Vol. 29, No. 3

485--506

EN

A new 4-D dynamical system exhibiting chaos is introduced in this work. The proposed nonlinear plant with chaos has an unstable rest point and a line of rest points. Thus, the new nonlinear plant exhibits hidden attractors. A detailed dynamic analysis of the new nonlinear plant using bifurcation diagrams is described. Synchronization result of the new nonlinear plant with itself is achieved using Integral Sliding Mode Control (ISMC). Finally, a circuit modelusing MultiSim of the new 4-D nonlinear plant with chaos is carried out for practical use.

11

A numerical study of synchronization in the process of biochemical substance exchange in a diffusively coupled ring of cells

80%

Mihailović D. , Balaž I. , Arsenić I.

Open Physics

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2013

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tom 11

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nr 4

440-447

EN

In this paper we numerically investigate a model of a diffusively coupled ring of cells. To model the dynamics of individual cells we propose a map with cell affinity, which is a generalization of the logistic map. First, the basic features of a one-cell system are studied in terms of the Lyapunov exponent, Kolmogorov complexity and Sample Entropy. Second, the notion of observational heterarchy, which is a perpetual negotiation process between different levels of the description of a phenomenon, is reviewed. After these preliminaries, we study how the active coupling induced by the consideration of the observational heterarchy modifies the synchronization property of the model with N=100 cells. It is shown numerically that the active coupling enhances synchronization of biochemical substance exchange in several different conditions of cell affinity.

12

Energy balance of two synchronized self-excited pendulums with different masses

80%

Kapitaniak T. , Czołczyński K. , Perlikowski P. , Stefański A.

Journal of Theoretical and Applied Mechanics

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2012

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tom Vol. 50 nr 3

729-741

EN

We consider the synchronization of two self-excited pendulums with different masses. We show that such pendulums hanging on the same beam can show almost-complete (in-phase) and almost-antiphase synchronizations in which the difference of the pendulums displacements is small. Our approximate analytical analysis allows one to derive the synchronization conditions and explains the observed types of synchronizations as well as gives an approximate formula for amplitudes of both the pendulums and the phase shift between them. We consider the energy balance in the system and show how the energy is transferred between the pendulums via the oscillating beam allowing synchronization of the pendulums.

PL

Artykuł prezentuje analizę zjawiska synchronizacji dwóch wahadeł samowzbudnych o różnych masach. Pokazano, że jeśli takie wahadła zostaną zawieszone na wspólnej, ruchomej podstawie, zachodzi zjawisko ich (prawie) zupełnej lub (prawie) antyfazowej synchronizacji. Analiza bilansu energetycznego układu pozwala na określenie parametrów układu w stanie synchronizacji (amplitudy drgań i przesunięcia fazowe). Analiza bilansu energetycznego wyjaśnia także mechanizm synchronizowania się ruchu wahadeł: stały przepływ strumienia energii od jednego wahadła, via wspólna ruchoma podstawa, do drugiego wahadła powoduje, że ruch układu jest okresowy, a przesunięcia fazowe pomiędzy wahadłami przyjmują stałe, charakterystyczne wartości.

13

Skuteczność cyfrowego uśredniania koherentnego przy nieidealnej synchronizacji

80%

Domańska A.

Pomiary Automatyka Kontrola

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2012

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tom R. 58, nr 9

782-784

PL

Artykuł przedstawia zagadnienie oceny wpływu nieidealnej synchronizacji na wartości próbek sygnału będącego rezultatem cyfrowego uśredniania koherentnego. Podano zależność określającą wariancję wartości sygnału po uśrednieniu, z powodu błędu synchronizacji. W przypadku sygnału sinusoidalnego, wariancja ta zależy od: wariancji błędu synchronizacji, amplitudy, relacji między częstotliwością sygnału i częstotliwością próbkowania oraz od liczby próbek. Przy niezerowym błędzie synchronizacji, uśrednianie koherentne redukując szum addytywny powoduje zniekształcenia chwilowych wartości sygnału będących wynikiem uśredniania.

EN

Digital cumulative averaging (CAV) is a form of the digital filtration and belongs to the methods for noise reduction in repeatable signals. An advantage distinguishing CAV from the usual digital filtration is that it also causes noise reduction in the signal band. The CAV algorithm realizes two operations: synchronization of segments and coherence averaging of samples. The paper presents the problem of evaluating the influence of non ideal synchronization on the value of samples of the signal being the CAV result. If the synchronization error does not occur, CAV reducing the noise does not change the recovered signal value. For the non-zero synchronization error, CAV reducing the noise causes distortions of temporary values of this signal. The synchronization error influences the error of the sample value and, in consequence, the error of the CAV result. The CAV efficiency depends, in such a case, on the synchronization accuracy of the converted segments. Section 2 describes the system CAV structure. In Section 3 there is given the dependence defining the variance of the single sample and the sample obtained from CAV caused by the synchronization error. In the case of sinusoidal signals, the variance of the result (samples of the signal after CAV) due to the synchronization error depends on: the synchronization error variance, the amplitude, the relation between the signal frequency and the sampling frequency as well as the number of the averaged samples/ repetitions. One can determine the limit value of this variance.

14

A velocity measurement method based on scaling parameter estimation of chaotic system

80%

Liu L. , Hu J. , He Z. , Han C. , Li H. , Li J.

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tom Vol. 18, nr 2

275-281

EN

In this paper, we propose a new method of measuring the target velocity by estimating the scaling parameter of a chaos-generating system. First, we derive the relation between the target velocity and the scaling parameter of the chaos-generating system. Then a new method for scaling parameter estimation of the chaotic system is proposed by exploiting the chaotic synchronization property. Finally, numerical simulations show the effectiveness of the proposed method in target velocity measurement.

15

Testing of a two-speed synchronous motor

80%

Antal L. , Zawilak T.

Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały

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2009

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tom Vol. 63, nr 29

17-29

EN

This work shows the results of the tests on a 600/1050kW two-speed synchronous motor with the nominal speeds of 500 and 600 rpm. Motors of this type with powers ranging from 600 to 3150kW are modified single-speed motors. They have been working for several years in coal and copper mines. The use of two-speed drive motors makes it possible to regulate the speed in steps and, thus, regulate the output of the fan and the power drawn by the motor. The possibility of reactive power compensation is intact and mitigation of the motor starting processes is achieved.

16

Coupling multistable systems: uncertainty due to the initial positions on the attractors

80%

Kuzma P. , Kapitaniak M. , Kapitaniak T.

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2014

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tom Vol. 52 nr 1

281--284

EN

We consider the coupling of multistable nonidentical systems. For small values of the coupling coefficient the behavior of the coupled system strongly depends on the actual position of trajectories on their attractors in the moment when the coupling is introduced. After reaching the coupling threshold value, this dependence disappears. We give an evidence that this behavior is robust as it exists for a wide range of parameters and different types of coupling. We argue why this behavior cannot be considered as a dependence on the initial conditions.

17

System zarządzania siecią synchroniczną Alcatel 1354 SY

80%

Roszkiewicz M.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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1998

|

tom nr 7

485-487

PL

Przedstawiono system zarządzania siecią synchronizacyjną firmy Alcatel o symbolu 1354 SY. Omówiono jego architekturę, parametry wydajnościowe oraz współpracę z pozostałymi systemami firmy Alcatel.

EN

Alcatel's synchronization network manager 1354 SY is presented. Its architecture, performance, as well as its place within Alcatel network management products line is discussed.

18

Spatial synchronization of unbalanced rotors excited with paralleled and counterrotating motors in a far resonance system

80%

Fang P. , Zou M. , Peng H. , Du M. , Hu G. , Hou Y.

Journal of Theoretical and Applied Mechanics

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2019

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tom Vol. 57 nr 3

723--738

EN

Dynamic characteristics of the vibration screening machinery is influenced by synchronization between induction motors. Therefore, estimating the synchronous state between the motors is a crucial process for designing the vibration screening machinery. In this paper, two rotors excited with paralleled and counterrotating motors in a far resonance system are concerned. To master the synchronization of the system, the dynamic model is firstly established; then, the synchronous condition of the system is derived with the Poincar´e method; subsequently, the synchronous stability of the system is discussed by the Hamilton principle; finally, some computation simulations are implemented to verify correctness of theoretical analysis. The research result shows that the system actuated by rotors of the identical mass is planar motion as the stable phase difference between the rotors is stabilized in the zero phase. The system actuated by nonequivalent mass rotors exhibits spatial motion as the stable phase difference stabilizes in a nonzero phase.

19

On the size of stack and synchronization alphabets of tree automata

80%

Rahonis G. , Salomaa K.

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1998

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tom Vol. 36, nr 1

57-69

EN

We consider classes of forests defined by synchronized and pushdown tree automata having a fixed size of , respectively, synchronization or pushdown alphabet. We show that such families have nice properties, for instance, they from either a sheaf or a strict alphabetic cone of forests. Furthermore, for the (deterministic and nondeterministic) synchronized tree automata and the real-time pushdown tree automata we obtain a strict infinite forest hierarchy with respect to the alphabet size.

20

Merging States and Synchronization Problem

80%

Roman A.

Schedae Informaticae

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2006

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tom Vol. 15

95-108

EN

In this paper we introduce the notion of merging states and merging systems and we use it for the classification of finite de- terministic automata without initial and final states. We investigate the dependencies between the structure of an automaton described by merging systems and maximal lengths of minimal synchronizing words for automata which structures belong to the given class of merging sys- tems. Numerical results for certain classes of automata are presented. We also give some properties of merging systems themselves. The work is motivated by the famous, unsolved Cerny Conjecture. The aim of this paper is to propose the use of merging systems in the research on the Conjecture.