6,372 research outputs found
Dynamical approach to spectator fragmentation in Au+Au reactions at 35 MeV/A
The characteristics of fragment emission in peripheral Au+Au
collisions 35 MeV/A are studied using the two clusterization approaches within
framework of \emph{quantum molecular dynamics} model. Our model calculations
using \emph{minimum spanning tree} (MST) algorithm and advanced clusterization
method namely \emph{simulated annealing clusterization algorithm} (SACA) showed
that fragment structure can be realized at an earlier time when spectators
contribute significantly toward the fragment production even at such a low
incident energy. Comparison of model predictions with experimental data reveals
that SACA method can nicely reproduce the fragment charge yields and mean
charge of the heaviest fragment. This reflects suitability of SACA method over
conventional clusterization techniques to investigate spectator matter
fragmentation in low energy domain.Comment: 6 pages, 5 figures, accepte
Complex structures in generalized small worlds
We propose a generalization of small world networks, in which the
reconnection of links is governed by a function that depends on the distance
between the elements to be linked. An adequate choice of this function lets us
control the clusterization of the system. Control of the clusterization, in
turn, allows the generation of a wide variety of topologies.Comment: 4 pages, 6 figures, RevTe
Local modularity measure for network clusterizations
Many complex networks have an underlying modular structure, i.e., structural
subunits (communities or clusters) characterized by highly interconnected
nodes. The modularity has been introduced as a measure to assess the
quality of clusterizations. has a global view, while in many real-world
networks clusters are linked mainly \emph{locally} among each other
(\emph{local cluster-connectivity}). Here, we introduce a new measure,
localized modularity , which reflects local cluster structure. Optimization
of and on the clusterization of two biological networks shows that the
localized modularity identifies more cohesive clusters, yielding a
complementary view of higher granularity.Comment: 5 pages, 4 figures, RevTex4; Changed conten
Estimation of protein folding probability from equilibrium simulations
The assumption that similar structures have similar folding probabilities
() leads naturally to a procedure to evaluate for every
snapshot saved along an equilibrium folding-unfolding trajectory of a
structured peptide or protein. The procedure utilizes a structurally
homogeneous clustering and does not require any additional simulation. It can
be used to detect multiple folding pathways as shown for a three-stranded
antiparallel -sheet peptide investigated by implicit solvent molecular
dynamics simulations.Comment: 7 pages, 4 figures, supplemetary material
Theoretical description of mixed film formation at the air/water interface : carboxylic acids–fatty amines
Thermodynamic parameters of mixed monolayer formation of aliphatic amines CnH2n+1NH2 and carboxylic acids CnH2n+1COOH (n = 6–16) are calculated using the quantum chemical semiempirical PM3 method. Four types of mixed dimers and tetramers amine–acid are considered. The total contribution of interactions between the hydrophilic parts of amine and acid into clusterization Gibbs energy is slightly lower than the corresponding interactions for individual surfactants. It suggests a synergetic interaction between the regarded amphiphilic compounds as proved by experimental data in the literature. Two types of competitive film formation are possible: mixed 2D film 1, where the molecules of the minor component are single distributed among the molecules of the prevailing second component (mixture of components on molecular level), and 2D film 2 with a domain structure comprised of pure component “islands” linked together. The dependence of the Gibbs energy of clusterization per monomer for 2D film 1 on the component mole fraction shows that the maximum synergetic effect is typical for the case that both surfactants have the same even number of carbon atoms in the hydrocarbon chain and form an equimolar mixture. Formation of 2D film 1 is more preferable than that of 2D film 2, if the difference of the hydrocarbon chain lengths is not larger than 5 methylene units. The limiting mole fraction of carboxylic acids in such mixed monolayers is 66.7%
Jet analysis by Deterministic Annealing
We perform a comparison of two jet clusterization algorithms. The first one
is the standard Durham algorithm and the second one is a global optimization
scheme, Deterministic Annealing, often used in clusterization problems, and
adapted to the problem of jet identification in particle production by high
energy collisions; in particular we study hadronic jets in WW production by
high energy electron positron scattering. Our results are as follows. First, we
find that the two procedures give basically the same output as far as the
particle clusterization is concerned. Second, we find that the increase of CPU
time with the particle multiplicity is much faster for the Durham jet
clustering algorithm in comparison with Deterministic Annealing. Since this
result follows from the higher computational complexity of the Durham scheme,
it should not depend on the particular process studied here and might be
significant for jet physics at LHC as well.Comment: 15 pages, 4 figure
Spectator matter fragmentation in Au+Au reactions: Phase space analysis
Clusterization in phase space has been analyzed for peripheral Au+Au
reactions at 1000 AMeV using simulated annealing clusterization algorithm
(SACA). We investigate how these fragments are correlated in phase space and
compare our model calculations with minimum spanning tree (MST) method. Our
theoretical study highlights the importance of binding energy criterion in
recognizing the fragment structure. MST method however, fails to break-up the
spectator matter effectively and thus under-estimates the multiplicity of
intermediate mass fragments (IMFs).Comment: 2 pages, 2 figure
Introduction Of Clusterization Principles In The Solution Of Problems Of Energy Efficiency And Ecological Safety Of The Existent Building Fund
The aim of the work is to introduce clusterization principles in the solution of problems of energy efficiency and ecological safety of the existent building fund. The material of the research is the process of modeling of energetically effective architecture-building clusters. In this sense it is topical and expedient to elaborate technologies and schemes, able to support making decisions as to the formation of energetically effective architecture-building clusters. The main attention is paid to the solution of infrastructure problems of energy saving of the architecture-building branch, connected with the absence of universal models, distinct algorithms of the formation of energy efficiency clusters and reliable instruments of their activity optimization. But realization of advantages of energy efficiency clusters is possible only at introducing effective mechanisms of the formation of a structure, able to provide a result, optimal by an energy efficiency criterion. The work offers a scheme of the formation process of such structure. The synthesis of models of energetically effective architecture-building clusters is based on principles of the systemic construction of geometric models and provides the imitative modeling of different development scenarios of synthesized clusters. At this stage of the research a function of making decisions as to the real cluster formation is left for experts. But an algorithm of the synthesis of models provides the formation of a knowledge base that will be in further a base of an “internal model” of the intellectual system of supporting decisions making, elaborated for modeling cluster structures. The scientific novelty of the work is in the elaboration of theoretical bases of the technology of coordinating the structure with object properties
Deuteron-deuteron collision at 160 MeV
The experiment was carried out using BINA detector at KVI in Groningen. For
the first time an extensive data analysis of the data collected in back part of
the detector is presented, where a clusterization method is utilized for
angular and energy information. We also present differential cross-sections for
the (dddpn) breakup reaction within \textit{dp} quasi-free
scattering limit and their comparison with first calculations based on Single
Scattering Approximation (SSA) approach.Comment: 6 pages, 4 figures, presented at Jagiellonian Symposium 2015 in
Krakow, PhD wor
- …