PL
 |
EN
Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 12

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  complex network
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote Realizing actual feedback control of complex network
100%
Tu C. , Cheng Y.
Open Physics
|
2014
|
tom 12
|
nr 6
406-414
EN
In this paper, we present the concept of feedbackability and how to identify the Minimum Feedbackability Set of an arbitrary complex directed network. Furthermore, we design an estimator and a feedback controller accessing one MFS to realize actual feedback control, i.e. control the system to our desired state according to the estimated system internal state from the output of estimator. Last but not least, we perform numerical simulations of a small linear time-invariant dynamics network and a real simple food network to verify the theoretical results. The framework presented here could make an arbitrary complex directed network realize actual feedback control and deepen our understanding of complex systems.
2
Content available remote Estimating the varying topology of discrete-time dynamical networks with noise
100%
Tu C. , Cheng Y. , Chen K.
Open Physics
|
2013
|
tom 11
|
nr 8
1045-1055
EN
We propose an improved method to estimate the varying topology of discrete-time dynamical networks using autosynchronization. The networks considered in this paper can be weighted or unweighted and directed or undirected, and the dynamics of each node can be nonuniform. Furthermore, we suggest using a moving-average filter to suppress the influence of noise on parameter estimation. Finally, several examples are illustrated to verify the theoretical results by numerical simulation.
3
Content available remote Network science as a method of measuring language complexity
100%
Vitevitch M.
Poznań Studies in Contemporary Linguistics
|
2014
|
tom 50
|
nr 2
197-205
EN
The physical, mathematical, and information sciences have developed a number of ways to measure complexity and complex systems in the social, biological, and physical domains. One way of measuring complex systems that might be useful to language scientists is the set of tools from the interdisciplinary field known as network science. A number of studies that have used the tools of network science to examine various aspects of language and language processing are summarized. It is acknowledged that much work must be done to use the tools of network science to address the debate about the (equal) complexity of languages. However, this work may prove useful to language scientists interested in the (equal) complexity of languages, as well as in other topics about language. Furthermore, the distinct structural characteristics observed in networks of several languages to date may also prove useful to network scientists as they try to understand how certain structural characteristics influence network dynamics in other domains. Language scientists are urged to embrace the techniques of network science to address the question of the complexity of languages.
4
Content available remote Robust projective outer synchronization of coupled uncertain fractional-order complex networks
100%
Wang J. , Zhang Y.
Open Physics
|
2013
|
tom 11
|
nr 6
813-823
EN
In this work, we propose a novel projective outer synchronization (POS) between unidirectionally coupled uncertain fractional-order complex networks through scalar transmitted signals. Based on the state observer theory, a control law is designed and some criteria are given in terms of linear matrix inequalities which guarantee global robust POS between such networks. Interestingly, in the POS regime, we show that different choices of scaling factor give rise to different outer synchrony, with various special cases including complete outer synchrony, anti-outer synchrony and even a state of amplitude death. Furthermore, it is demonstrated that although stability of POS is irrelevant to the inner-coupling strength, it will affect the convergence speed of POS. In particular, stronger inner synchronization can induce faster POS. The effectiveness of our method is revealed by numerical simulations on fractional-order complex networks with small-world communication topology.
5
Content available On the influence of topological characteristics on robustness of complex networks
100%
Kasthurirathna D. , Piraveenan M. , Thedchanamoorthy G.
Journal of Artificial Intelligence and Soft Computing Research
|
2013
|
tom Vol. 3, No. 2
89--100
EN
In this paper, we explore the relationship between the topological characteristics of a complex network and its robustness to sustained targeted attacks. Using synthesised scale-free, small-world and random networks, we look at a number of network measures, including assortativity, modularity, average path length, clustering coefficient, rich club profiles and scale-free exponent (where applicable) of a network, and how each of these influence the robustness of a network under targeted attacks. We use an established robustness coefficient to measure topological robustness, and consider sustained targeted attacks by order of node degree. With respect to scale-free networks, we show that assortativity, modularity and average path length have a positive correlation with network robustness, whereas clustering coefficient has a negative correlation. We did not find any correlation between scale-free exponent and robustness, or rich-club profiles and robustness. The robustness of small-world networks on the other hand, show substantial positive correlations with assortativity, modularity, clustering coefficient and average path length. In comparison, the robustness of Erdos-Renyi random networks did not have any significant correlation with any of the network properties considered. A significant observation is that high clustering decreases topological robustness in scale-free networks, yet it increases topological robustness in small-world networks. Our results highlight the importance of topological characteristics in influencing network robustness, and illustrate design strategies network designers can use to increase the robustness of scale-free and small-world networks under sustained targeted attacks.
6
Content available Diffusion in Networks
100%
Kasprzak R.
Journal of Telecommunications and Information Technology
|
2012
|
tom nr 2
99-106
EN
In this paper a concept of method and its application examining a dynamic of diffusion processes in networks is considered. Presented method was used as a core framework for system CARE (Creative Application to Remedy Epidemics).
7
Content available The prediction of terrorist threat on the basis of semantic association acquisition and complex network evolution
100%
Najgebauer A. , Antkiewicz R. , Chmielewski M. , Kasprzak R.
Journal of Telecommunications and Information Technology
|
2008
|
tom nr 2
14-20
EN
In this paper, which is the continuation of an MCC 2006 Conf. publication by the same group of authors, we propose a concept of early detection of terrorist action preparation activities. Our ideas rely on semantic and complex networks to extract useful information for terrorist threat indication. Presented methods will be used as a core framework for Early Warning System.
8
Content available remote Quantitative typological analysis of Romance languages
88%
Liu H. , Xu C.
Poznań Studies in Contemporary Linguistics
|
2012
|
tom 48
597-625
EN
Based on real-text corpora with syntactic annotation, this study quantitatively addressed the following two questions: whether quantitative methods and indexes can point to the diachronic syntactic drifts characterizing the evolution from Latin to Romance languages and whether these methods and indexes can provide evidence to evince the shared syntactic features among Romance languages and define them as a distinctive language subgroup. Our study shows that the distributions of dependency directions are suggestive of positive answers to the above two questions. In addition, the dependency syntactic networks extracted from the dependency treebanks reflect the degree of inflectional variation of a language, and the clustering analysis shows that these parameters, in spite of some imperfections, can also help differentiate Romance languages from Latin diachronically and from other languages synchronically.
9
Content available remote Statistical properties of complex network for seismicity using depth-incorporated influence radius
75%
He X. , Wang L. , Zhu H. , Liu Z.
Acta Geophysica
|
2019
|
tom Vol. 67, no. 6
1515--1523
EN
In recent years, seismic time series has been used to construct complex network models in order to describe the seismic complexity. The effect of the factor focal depth has been elided in some of these models. In this paper, we aim to construct a new complex network model for seismicity by considering depth factor from the earthquake catalog and investigate the statistical properties of the network. Since the networks have been proved to be scale-free and small-world properties, the new network models should be studied whether the properties have changed. The results show that the new network model by considering depth factor is still scale-free and small-world. However, it is found that its average degree is smaller than the original network. The clustering coefficient increases at the year including mainshocks. The assortativity coefficient, which demonstrates preferential attachment of nodes, is positive and shows consistent pattern when main shocks occur.
10
Content available remote The Local Importance of Node in Complex Networks
75%
Xiao L. , Chen L. , Xiao J.
Przegląd Elektrotechniczny
|
2013
|
tom R. 89, nr 1b
236--238
EN
This paper presents a new weighted graph to represent the strength of relationships between nodes, this graph can be a direct reflection of the interaction frequency of interconnected nodes, through the calculation of the weights, it can measure the local importance of the node results show that the local importance of a node is proportional to the degree of the node and the interaction frequency of the node. Under certain conditions, the local importance is inversely proportional to the degree of its adjacent nodes.
PL
W artykule przedstawiono nowy diagram ważony do prezentacji siły relacji między korzeniami sieci. Graf może być bezpośrednim odbiciem wzajemnych oddziaływać częstotliwościowych współpracujących korzeni. Poprzez obliczenia wag może oceniać znaczenie korzenia lokalnego. Wyniki wskazują, że znaczenie korzenia lokalnego jest proporcjonalne do stopnia korzenia i częstotliwości współpracy. W szczególnych warunkach lokalne znaczenie jest odwrotnie proporcjonalne do stopnie korzenia przylegającego.
11
Content available Elements evaluation of soft-hardware objects with complex physical, information structures links
63%
Khusainov P.
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
|
2019
|
tom T. 9, nr 1
49--52
EN
It is offered to consider the index of element importance for multi-element soft-hardware objects with complex structure physical, information links. Elements evaluation is carried out in the planning of implementation of diagnostic tests. The methodological basis is based on the use of formal objects "network of uniformity soft-hardware devices", "processes operating environment", the diagnostic model of inter-process communication tract.
PL
W artykule przedstawiono analizę możliwości wykorzystania wskaźnika oceny wieloelementowych obiektów oprogramowania i sprzętu o złożonej strukturze komunikacji fizycznej i informacyjnej. Ocena elementów odbywa się przy planowaniu wykonania testów diagnostycznych. Podstawa metodologiczna oparta jest na wykorzystaniu obiektów formalnych "sieć tego samego typu oprogramowania i sprzętu", "środowisko operacyjne procesów obliczeniowych", modelu komunikacji międzyprocesowej.
12
Content available Optimal resource allocation for safety in distributed complex electromechanical systems
51%
Han Z. , Gao J. , Xing L. , Chen F.
Eksploatacja i Niezawodność
|
2011
|
tom nr 2
4-12
EN
Existing optimal resource allocation for system safety mainly concentrates on series/parallel systems or systems that can be converted into series/parallel models. However, for some distributed complex electromechanical systems, it is very difficult or even impossible to refine them into a series/parallel model; in addition, the safety of some system units is immeasurable because of the coupling relationship complexity in the system composition structure. In this paper, a novel method based on complex networks and path set-based dynamic programming is proposed for the optimal resource allocation for maximal safety of distributed complex electromechanical systems with non-series-parallel structures. As a measurement of the system safety, safety importance is defined, which is a function of two safety feature parameters - accident loss and accident probability. A practical system is taken as an example to illustrate and verify the feasibility and applicability of the proposed method.
PL
Istniejące strategie optymalnej alokacji zasobów służące zapewnieniu bezpieczeństwa systemów skupiają się głównie na systemach szeregowo-równoległych lub na systemach, które można przekształcić w modele szeregowo-równoległe. Jednakże, w przypadku niektórych złożonych rozproszonych systemów elektromechanicznych, przetworzenie na model szeregowo-równoległy może być bardzo trudne lub wręcz niemożliwe. Dodatkowo, z powodu złożoności relacji sprzężeń w fizycznej strukturze tego rodzaju systemów, bezpieczeństwo niektórych jednostek systemowych jest niemierzalne. W niniejszym artykule przedstawiono nową metodę optymalnej alokacji zasobów gwarantującą maksymalne bezpieczeństwo złożonych rozproszonych systemów elektromechanicznych o strukturze innej niż szeregowo-równoległa. Metoda ta oparta jest na sieciach złożonych i wykorzystuje dynamiczne programowanie bazujące na zbiorach ścieżek. Jako miarę bezpieczeństwa systemu zastosowano pojęcie hierarchii bezpieczeństwa, zdefiniowane jako funkcja dwóch parametrów bezpieczeństwa: strat z tytułu awarii oraz prawdopodobieństwa awarii. Dla zilustrowania proponowanej metody i weryfikacji jej przydatności i możliwości zastosowania, przedstawiono przykład rzeczywistego systemu.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.