824 research outputs found
Network synchronization of groups
In this paper we study synchronized motions in complex networks in which
there are distinct groups of nodes where the dynamical systems on each node
within a group are the same but are different for nodes in different groups.
Both continuous time and discrete time systems are considered. We initially
focus on the case where two groups are present and the network has bipartite
topology (i.e., links exist between nodes in different groups but not between
nodes in the same group). We also show that group synchronous motions are
compatible with more general network topologies, where there are also
connections within the groups
Coexistence of ferromagnetism and superconductivity in the hybrid ruthenate-cuprate compound RuSr_2GdCu_2O_8 studied by muon spin rotation (\mu SR) and DC-magnetization
We have investigated the magnetic and the superconducting properties of the
hybrid ruthenate-cuprate compound RuSr_{2}GdCu_{2}O_{8} by means of zero-field
muon spin rotation- (ZF-SR) and DC magnetization measurements. The
DC-magnetisation data establish that this material exhibits ferromagnetic order
of the Ru-moments () below T_{Curie} = 133 K and
becomes superconducting at a much lower temperature T_c = 16 K. The ZF-SR
experiments indicate that the ferromagnetic phase is homogeneous on a
microscopic scale and accounts for most of the sample volume. They also suggest
that the magnetic order is not significantly modified at the onset of
superconductivity.Comment: improved version submitted to Phys. Rev.
Analysis of complex singularities in high-Reynolds-number Navier-Stokes solutions
Numerical solutions of the laminar Prandtl boundary-layer and Navier-Stokes
equations are considered for the case of the two-dimensional uniform flow past
an impulsively-started circular cylinder. We show how Prandtl's solution
develops a finite time separation singularity. On the other hand Navier-Stokes
solution is characterized by the presence of two kinds of viscous-inviscid
interactions that can be detected by the analysis of the enstrophy and of the
pressure gradient on the wall. Moreover we apply the complex singularity
tracking method to Prandtl and Navier-Stokes solutions and analyze the previous
interactions from a different perspective
The complex network of global cargo ship movements
Transportation networks play a crucial role in human mobility, the exchange
of goods, and the spread of invasive species. With 90% of world trade carried
by sea, the global network of merchant ships provides one of the most important
modes of transportation. Here we use information about the itineraries of
16,363 cargo ships during the year 2007 to construct a network of links between
ports. We show that the network has several features which set it apart from
other transportation networks. In particular, most ships can be classified in
three categories: bulk dry carriers, container ships and oil tankers. These
three categories do not only differ in the ships' physical characteristics, but
also in their mobility patterns and networks. Container ships follow regularly
repeating paths whereas bulk dry carriers and oil tankers move less predictably
between ports. The network of all ship movements possesses a heavy-tailed
distribution for the connectivity of ports and for the loads transported on the
links with systematic differences between ship types. The data analyzed in this
paper improve current assumptions based on gravity models of ship movements, an
important step towards understanding patterns of global trade and bioinvasion.Comment: 7 figures Accepted for publication by Journal of the Royal Society
Interface (2010) For supplementary information, see
http://www.icbm.de/~blasius/publications.htm
Implementasi Algoritma Dijkstra Dalam Penentuan Jalur Terpendek Di YOGYAKARTA Menggunakan GPS Dan Qt Geolocation
With the development of information technology, the map is no longer in the form of sheet or book. Currently there is a digital map services already invested in mobile devices. Google Maps is one of the leading providers of online digital map which can be accessed using the Application Programming Interface (API) is available using tools such as Qt. Qt is a C + + framework which provides a library to get the location using a GPS device to the library QtGeolocation. By implementing Dijkstra's algorithm, the problem of determining the shortest path towards a desired location of a user's location can be overcome. This study discusses how to implement the algorithm to find the shortest path Djikstra in Yogyakarta-based mobile devices
Multimodality in Aerodynamic Wing Design Optimization
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143093/1/6.2017-3753.pd
Zipf law in the popularity distribution of chess openings
We perform a quantitative analysis of extensive chess databases and show that
the frequencies of opening moves are distributed according to a power-law with
an exponent that increases linearly with the game depth, whereas the pooled
distribution of all opening weights follows Zipf's law with universal exponent.
We propose a simple stochastic process that is able to capture the observed
playing statistics and show that the Zipf law arises from the self-similar
nature of the game tree of chess. Thus, in the case of hierarchical
fragmentation the scaling is truly universal and independent of a particular
generating mechanism. Our findings are of relevance in general processes with
composite decisions.Comment: 5 pages, 4 figure
Chaos induced coherence in two independent food chains
Coherence evolution of two food web models can be obtained under the stirring
effect of chaotic advection. Each food web model sustains a three--level
trophic system composed of interacting predators, consumers and vegetation.
These populations compete for a common limiting resource in open flows with
chaotic advection dynamics. Here we show that two species (the top--predators)
of different colonies chaotically advected by a jet--like flow can synchronize
their evolution even without migration interaction. The evolution is
charaterized as a phase synchronization. The phase differences (determined
through the Hilbert transform) of the variables representing those species show
a coherent evolution.Comment: 5 pages, 5 eps figures. Accepted for publication in Phys. Rev.
Resonance and frequency-locking phenomena in spatially extended phytoplankton-zooplankton system with additive noise and periodic forces
In this paper, we present a spatial version of phytoplankton-zooplankton
model that includes some important factors such as external periodic forces,
noise, and diffusion processes. The spatially extended
phytoplankton-zooplankton system is from the original study by Scheffer [M
Scheffer, Fish and nutrients interplay determines algal biomass: a minimal
model, Oikos \textbf{62} (1991) 271-282]. Our results show that the spatially
extended system exhibit a resonant patterns and frequency-locking phenomena.
The system also shows that the noise and the external periodic forces play a
constructive role in the Scheffer's model: first, the noise can enhance the
oscillation of phytoplankton species' density and format a large clusters in
the space when the noise intensity is within certain interval. Second, the
external periodic forces can induce 4:1 and 1:1 frequency-locking and spatially
homogeneous oscillation phenomena to appear. Finally, the resonant patterns are
observed in the system when the spatial noises and external periodic forces are
both turned on. Moreover, we found that the 4:1 frequency-locking transform
into 1:1 frequency-locking when the noise intensity increased. In addition to
elucidating our results outside the domain of Turing instability, we provide
further analysis of Turing linear stability with the help of the numerical
calculation by using the Maple software. Significantly, oscillations are
enhanced in the system when the noise term presents. These results indicate
that the oceanic plankton bloom may partly due to interplay between the
stochastic factors and external forces instead of deterministic factors. These
results also may help us to understand the effects arising from undeniable
subject to random fluctuations in oceanic plankton bloom.Comment: Some typos errors are proof, and some strong relate references are
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