Petri transport networks Sedykh, I; Demakhin, D
Journal of physics. Conference series,
05/2020, Letnik:
1553, Številka:
1
Journal Article
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This paper presents a new class of Petri nets - Petri transport networks, used to simulate the transport's systems. This class can be attributed to hierarchical temporal colored probabilistic Petri ...nets. The paper gives a definition, basic concepts, structure and functioning rules of Petri transport networks. The relevance of the topic raised in the article is due to increasing attention to the development of transport systems, their evolution and modernization. Modern management methods, various mechanisms for regulating traffic flows, infrastructural extensions, all this does not meet the challenges posed by modern transport infrastructure. Moreover, the problem is increasing every year. Petri transport networks introduced in the work, are a convenient tool ohms to simulate the transport's systems of any complexity and scale. A new class of Petri transport networks is characterized by a hierarchical structure, in which the first level displays the entire system as a whole, the second - the internal structure of each object. Distinctive features are also the adjustment of the activation of traffic flows by means of a control marker, inter-level synchronization, separation of positions and transitions to types having different functions.
A model for a description of various fission fragment characteristics is proposed. The both nascent fission fragments consist of either the single-body or the two-body systems. The one-body fragment ...is a single nucleus, while the two-body fragment is the nucleus interacting with the
α
-particle. The
α
-particle have its origin to the neck nucleons. The yield of fission fragments in the model is linked to the number of states over the barrier of the saddle point, which is between the contacting and well-separated fission fragments. The crucial role of the three-body (nucleus-
α
-nucleus) systems at a passing through the saddle point is shown. After passing the saddle point, the
α
-particle is fusing with the nearest nucleus and forming the final fragment, because the distance between the nucleus and
α
-particle is smaller the barrier distance of the
α
-nucleus potential. As a result, the binary fission is realized in the framework of the model. If the
α
-particle is not fusing with the any fragment than the ternary fission occurs. The mass dependencies of the fragments yield, the kinetic energy and neutron emission number emitted by fragment calculated in the model agree well with available experimental data for binary fission of
235
U by thermal and 14 MeV neutrons. The root mean deviation between theoretical and experimental values of the decimal logarithm of nuclide yields for the fission of
235
U by thermal and 14 MeV neutrons are 0.756 and 1.02, respectively. The values of the ground-state quadrupole deformation of neutron-rich nuclei related to the fragments are estimated.
.
Simple relations for a calculation of the barrier height
B
, radius
R
and curvature
ℏ
ω
parameters used in the Wong formula for an evaluation of the heavy-ion fusion cross section are presented. ...These relations are obtained by a fitting of 1995 experimental cross section values measured for 85 even-even heavy-ion systems ranging from
12
C +
12
C with
Z
1
Z
2
=
36
to
58
Ni +
124
Sn with
Z
1
Z
2
=
1400
. Substituting these formulas for
B
,
R
and
ℏ
ω
into the Wong formula we can estimate both the fusion cross section of different spherical nuclei and the astrophysical S-factor. The value of the root-mean-square error of the decimal logarithm of the fusion cross section is 0.225.
This Letter presents measurements of the elliptic flow of charged particles as a function of pseudorapidity and centrality from Cu-Cu collisions at 62.4 and 200 GeV using the PHOBOS detector at the ...Relativistic Heavy Ion Collider. The elliptic flow in Cu-Cu collisions is found to be significant even for the most central events. For comparison with the Au-Au results, it is found that the detailed way in which the collision geometry (eccentricity) is estimated is of critical importance when scaling out system-size effects. A new form of eccentricity, called the participant eccentricity, is introduced which yields a scaled elliptic flow in the Cu-Cu system that has the same relative magnitude and qualitative features as that in the Au-Au system.
.
The ratio
Γ
n
(
E
)
/
Γ
f
(
E
)
is calculated using different expressions for the fission width, which take into account and ignore the dependence of the fission barrier on the excitation energy. A ...strong influence of the energy-dependent fission barrier on the ratio
Γ
n
(
E
)
/
Γ
f
(
E
)
is shown. The dependence of the synthesis of superheavy nuclei on the ratio
Γ
n
(
E
)
/
Γ
f
(
E
)
is discussed. The experimental values of the ratio
Γ
f
(
E
)
/
Γ
n
(
E
)
in
188
Os and
210, 212
Po are well described using the fission width with a barrier dependent on the excitation energy. The values of the fission barrier height for these nuclei are estimated.
Introduction. The development of a mathematical model for the groundwater level of a deposit of cement raw materials located in the Zadonian-Yelets aquifer, which is the principal domestic water ...supply source for the city of Lipetsk, is considered. Therefore, it is necessary to provide ongoing monitoring and to have the possibility to predict the water level under the field development. The work objectives are the identification and study of a dynamic neighborhood model with variable hierarchical neighborhoods of the groundwater level that enables to adequately predict value of the water level in the examined wells.
Materials and Methods. The definition of a dynamic neighborhood model with variable hierarchical neighborhoods is given, differing by time-varying double-level neighborhood communications between the first- and second-level nodes. At each next discrete instant of time, the neighborhood model nodes change their state under the influence of the online parameters and node states included in their neighborhood. As a subcase, we consider a model with line state recalculation functions. Parametric identification of the dynamic neighborhood model consists in finding the system parameters for each second-level node, and is based on the ordinary least squares.
Research Results. A linear dynamic neighborhood model with variable hierarchical neighborhoods for predicting the groundwater level in a cement raw material deposit located in the Zadonian-Yelets aquifer is developed. The software using C++ is developed for the parametric identification and simulation of the functioning of the dynamic neighborhood model under consideration. It enables to determine parameters of the node state recalculation functions for a given structure, and also to predict the model behavior in the operation process. A hierarchical structure is given, and a parametric identification of the linear dynamic neighborhood model of the groundwater level is carried out. After the parametric identification on the teaching data selection, the mathematical model is checked on the test sample.
Discussion and Conclusions. The obtained average ratio errors of the identification and forecast suggest the developed model validity and enable to recommend it for predicting the underground water level of a cement raw materials deposit.
The expression of dependence of the average total kinetic energy of fission fragments on the excitation energy of the fissioning system is obtained in a simple model, which takes into account the ...statistical and quantum properties. The experimental data of the average total kinetic energy of fragments formed in the fission of nuclei 234,236,239U and 240Pu are well described using the obtained expression in the wide range of the excitation energy of these nuclei. The origin of the energy dependence of the average total kinetic energy is discussed in details.
We report on measurements of directed flow as a function of pseudorapidity in Au + Au collisions at energies of square root of SNN = 19.6, 62.4, 130 and 200 GeV as measured by the PHOBOS detector at ...the BNL Relativistic Heavy Ion Collider. These results are particularly valuable because of the extensive, continuous pseudorapidity coverage of the PHOBOS detector. There is no significant indication of structure near midrapidity and the data surprisingly exhibit extended longitudinal scaling similar to that seen for elliptic flow and charged particle pseudorapidity density.
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