WorldWideScience

Sample records for cellular automaton simulations

  1. An improved cellular automaton method to model multispecies biofilms.

    Science.gov (United States)

    Tang, Youneng; Valocchi, Albert J

    2013-10-01

    Biomass-spreading rules used in previous cellular automaton methods to simulate multispecies biofilm introduced extensive mixing between different biomass species or resulted in spatially discontinuous biomass concentration and distribution; this caused results based on the cellular automaton methods to deviate from experimental results and those from the more computationally intensive continuous method. To overcome the problems, we propose new biomass-spreading rules in this work: Excess biomass spreads by pushing a line of grid cells that are on the shortest path from the source grid cell to the destination grid cell, and the fractions of different biomass species in the grid cells on the path change due to the spreading. To evaluate the new rules, three two-dimensional simulation examples are used to compare the biomass distribution computed using the continuous method and three cellular automaton methods, one based on the new rules and the other two based on rules presented in two previous studies. The relationship between the biomass species is syntrophic in one example and competitive in the other two examples. Simulation results generated using the cellular automaton method based on the new rules agree much better with the continuous method than do results using the other two cellular automaton methods. The new biomass-spreading rules are no more complex to implement than the existing rules. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. The Algorithm of Continuous Optimization Based on the Modified Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Oleg Evsutin

    2016-08-01

    Full Text Available This article is devoted to the application of the cellular automata mathematical apparatus to the problem of continuous optimization. The cellular automaton with an objective function is introduced as a new modification of the classic cellular automaton. The algorithm of continuous optimization, which is based on dynamics of the cellular automaton having the property of geometric symmetry, is obtained. The results of the simulation experiments with the obtained algorithm on standard test functions are provided, and a comparison between the analogs is shown.

  3. New cellular automaton designed to simulate geometration in gel electrophoresis

    Science.gov (United States)

    Krawczyk, M. J.; Kułakowski, K.; Maksymowicz, A. Z.

    2002-08-01

    We propose a new kind of cellular automaton to simulate transportation of molecules of DNA through agarose gel. Two processes are taken into account: reptation at strong electric field E, described in the particle model, and geometration, i.e. subsequent hookings and releases of long molecules at and from gel fibres. The automaton rules are deterministic and they are designed to describe both processes within one unified approach. Thermal fluctuations are not taken into account. The number of simultaneous hookings is limited by the molecule length. The features of the automaton are: (i) the size of the cell neighbourhood for the automaton rule varies dynamically, from nearest neighbors to the entire molecule; (ii) the length of the time step is determined at each step according to dynamic rules. Calculations are made up to N=244 reptons in a molecule. Two subsequent stages of the motion are found. Firstly, an initial set of random configurations of molecules is transformed into a more ordered phase, where most molecules are elongated along the applied field direction. After some transient time, the mobility μ reaches a constant value. Then, it varies with N as 1/ N for long molecules. The band dispersion varies with time t approximately as Nt1/2. Our results indicate that the well-known plateau of the mobility μ vs. N does not hold at large electric fields.

  4. Multidimensional traveling waves in the Allen–Cahn cellular automaton

    International Nuclear Information System (INIS)

    Murata, Mikio

    2015-01-01

    Ultradiscretization is a limiting procedure transforming a given difference equation into a cellular automaton. The cellular automaton constructed by this procedure preserves the essential properties of the original equation, such as the structure of exact solutions for integrable equations. In this article, a cellular automaton analog of the multidimensional Allen–Cahn equation which is not an integrable system is constructed by the ultradiscretization. Moreover, the traveling wave solutions for the resulting cellular automaton are given. The shape, behavior and stability of the solutions in ultradiscrete systems are similar to those in continuous systems. (paper)

  5. Simulation of emotional contagion using modified SIR model: A cellular automaton approach

    Science.gov (United States)

    Fu, Libi; Song, Weiguo; Lv, Wei; Lo, Siuming

    2014-07-01

    Emotion plays an important role in the decision-making of individuals in some emergency situations. The contagion of emotion may induce either normal or abnormal consolidated crowd behavior. This paper aims to simulate the dynamics of emotional contagion among crowds by modifying the epidemiological SIR model to a cellular automaton approach. This new cellular automaton model, entitled the “CA-SIRS model”, captures the dynamic process ‘susceptible-infected-recovered-susceptible', which is based on SIRS contagion in epidemiological theory. Moreover, in this new model, the process is integrated with individual movement. The simulation results of this model show that multiple waves and dynamical stability around a mean value will appear during emotion spreading. It was found that the proportion of initial infected individuals had little influence on the final stable proportion of infected population in a given system, and that infection frequency increased with an increase in the average crowd density. Our results further suggest that individual movement accelerates the spread speed of emotion and increases the stable proportion of infected population. Furthermore, decreasing the duration of an infection and the probability of reinfection can markedly reduce the number of infected individuals. It is hoped that this study will be helpful in crowd management and evacuation organization.

  6. Cellular automaton simulation of counter flow with paired pedestrians

    Directory of Open Access Journals (Sweden)

    Hui Xiong

    2011-12-01

    Full Text Available Knowledge on pedestrian behavior is the basis to build decision support system for crowd evacuation management in emergency. In this paper, the impact of paired walking behavior on pedestrian counter flow in a channel is studied. The pedestrian walking behaviors are simulated by the cellular automaton model and the pedestrians are classified as single right walker, single left walker, paired right walker, and paired left walker. Single walker can move forward, leftward, rightward or stand still. The paired pedestrians are considered as a combined unit similar to the single walker in terms of route choice and they can move to the same direction simultaneously. It is found that flow and velocity decrease with increase of the paired rate in case of stable density. Simulation results reveal the phase transitions in terms of density from free flow to the unstable flow and from the unstable flow to the congestion flow. However, the critical densities of phase transition are unaffected by the channel size.

  7. Cellular automatons applied to gas dynamic problems

    Science.gov (United States)

    Long, Lyle N.; Coopersmith, Robert M.; Mclachlan, B. G.

    1987-01-01

    This paper compares the results of a relatively new computational fluid dynamics method, cellular automatons, with experimental data and analytical results. This technique has been shown to qualitatively predict fluidlike behavior; however, there have been few published comparisons with experiment or other theories. Comparisons are made for a one-dimensional supersonic piston problem, Stokes first problem, and the flow past a normal flat plate. These comparisons are used to assess the ability of the method to accurately model fluid dynamic behavior and to point out its limitations. Reasonable results were obtained for all three test cases, but the fundamental limitations of cellular automatons are numerous. It may be misleading, at this time, to say that cellular automatons are a computationally efficient technique. Other methods, based on continuum or kinetic theory, would also be very efficient if as little of the physics were included.

  8. Level Set Structure of an Integrable Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Taichiro Takagi

    2010-03-01

    Full Text Available Based on a group theoretical setting a sort of discrete dynamical system is constructed and applied to a combinatorial dynamical system defined on the set of certain Bethe ansatz related objects known as the rigged configurations. This system is then used to study a one-dimensional periodic cellular automaton related to discrete Toda lattice. It is shown for the first time that the level set of this cellular automaton is decomposed into connected components and every such component is a torus.

  9. Cellular automaton simulation of pedestrian counter flow with different walk velocities

    International Nuclear Information System (INIS)

    Weng, W. G.; Chen, T.; Yuan, H. Y.; Fan, W. C.

    2006-01-01

    This paper presents a cellular automaton model without step back for pedestrian dynamics considering the human behaviors which can make judgments in some complex situations. This model can simulate pedestrian movement with different walk velocities through update at different time-step intervals. Two kinds of boundary conditions including periodic and open boundary for pedestrian counter flow are considered, and their dynamical characteristics are discussed. Simulation results show that for periodic boundary condition there are three phases of pedestrian patterns, i.e., freely moving phase, lane formation phase, and perfectly stopped phase at some certain total density ranges. In the stage of lane formation, the phenomenon that pedestrians exceed those with lower walk velocity through a narrow walkway can be found. For open boundary condition, at some certain entrance densities, there are two steady states of pedestrian patterns; but the first is metastable. Spontaneous fluctuations can break the first steady state, i.e., freely moving phase, and run into the second steady state, i.e., perfectly stopped phase

  10. 3D simulation of friction stir welding based on movable cellular automaton method

    Science.gov (United States)

    Eremina, Galina M.

    2017-12-01

    The paper is devoted to a 3D computer simulation of the peculiarities of material flow taking place in friction stir welding (FSW). The simulation was performed by the movable cellular automaton (MCA) method, which is a representative of particle methods in mechanics. Commonly, the flow of material in FSW is simulated based on computational fluid mechanics, assuming the material as continuum and ignoring its structure. The MCA method considers a material as an ensemble of bonded particles. The rupture of interparticle bonds and the formation of new bonds enable simulations of crack nucleation and healing as well as mas mixing and microwelding. The simulation results showed that using pins of simple shape (cylinder, cone, and pyramid) without a shoulder results in small displacements of plasticized material in workpiece thickness directions. Nevertheless, the optimal ratio of longitudinal velocity to rotational speed makes it possible to transport the welded material around the pin several times and to produce a joint of good quality.

  11. Mixing of two-component flow in a simplified stirred tank with cellular automaton method; Cellular automaton ho ni yoru kakuhan sonai no niseibunryu no kongo keisan

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, S; Takahashi, R [Tokyo Institute of Technology, Tokyo (Japan)

    1996-01-25

    The applicability of a cellular automaton technique to engineering problems will be examined by dealing with mixing in multicomponent flow. The quality and accumulation rate of the product depend on the mixing of raw materials basically. After thoroughly understanding the mixing process, we optimize the geometrical allocation of such elements as a propeller with casing, a chimney and a product output nozzle in a reactor. Usually mixing is formulated by partial differential equations of conservation laws and empirical formulae, and solved numerically by the finite difference technique. In order to evaluate the fine structure of time-dependent interfacial behavior in multicomponent flow, the cellular automaton technique is used, since this has an advantage of describing the pattern formation in detail. It will be demonstrated in the present paper that mixing of two-component immiscible flow is reasonably simulated mesoscopically. 13 refs., 17 figs.

  12. Cellular automaton-based position sensitive detector equalization

    Energy Technology Data Exchange (ETDEWEB)

    Ferrando, Nestor [Grupo de Diseno de Sistemas Digitales, Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)], E-mail: nesferjo@upvnet.upv.es; Herrero, V.; Cerda, J.; Lerche, C.W.; Colom, R.J.; Gadea, R.; Martinez, J.D.; Monzo, J.M.; Mateo, F.; Sebastia, A.; Benlloch, J.M. [Grupo de Diseno de Sistemas Digitales, Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2009-06-01

    Indirect position detectors based on scintillator crystals lack of spacial uniformity in their response. This happens due to crystal inhomogeneities and gain differences among the photomultiplier anodes. In order to solve this, PESIC, an integrated front-end for multianode photomultiplier based nuclear imaging devices was created. One of its main features is the digitally programmable gain adjustment for every photomultiplier output. On another front, cellular automata have been proved to be a useful method for dynamic system modeling. In this paper, a cellular automaton which emulates the behavior of the scintillator crystal, the photomultiplier and the front-end is introduced. Thanks to this model, an automatic energy-based calibration of the detector can be done by configuring the cellular automaton with experimental data and making it evolve up to an stable state. This can be useful as a precalibration method of the detector.

  13. Cellular automaton-based position sensitive detector equalization

    International Nuclear Information System (INIS)

    Ferrando, Nestor; Herrero, V.; Cerda, J.; Lerche, C.W.; Colom, R.J.; Gadea, R.; Martinez, J.D.; Monzo, J.M.; Mateo, F.; Sebastia, A.; Benlloch, J.M.

    2009-01-01

    Indirect position detectors based on scintillator crystals lack of spacial uniformity in their response. This happens due to crystal inhomogeneities and gain differences among the photomultiplier anodes. In order to solve this, PESIC, an integrated front-end for multianode photomultiplier based nuclear imaging devices was created. One of its main features is the digitally programmable gain adjustment for every photomultiplier output. On another front, cellular automata have been proved to be a useful method for dynamic system modeling. In this paper, a cellular automaton which emulates the behavior of the scintillator crystal, the photomultiplier and the front-end is introduced. Thanks to this model, an automatic energy-based calibration of the detector can be done by configuring the cellular automaton with experimental data and making it evolve up to an stable state. This can be useful as a precalibration method of the detector.

  14. Cellular automaton simulation examining progenitor hierarchy structure effects on mammary ductal carcinoma in situ.

    Science.gov (United States)

    Bankhead, Armand; Magnuson, Nancy S; Heckendorn, Robert B

    2007-06-07

    A computer simulation is used to model ductal carcinoma in situ, a form of non-invasive breast cancer. The simulation uses known histological morphology, cell types, and stochastic cell proliferation to evolve tumorous growth within a duct. The ductal simulation is based on a hybrid cellular automaton design using genetic rules to determine each cell's behavior. The genetic rules are a mutable abstraction that demonstrate genetic heterogeneity in a population. Our goal was to examine the role (if any) that recently discovered mammary stem cell hierarchies play in genetic heterogeneity, DCIS initiation and aggressiveness. Results show that simpler progenitor hierarchies result in greater genetic heterogeneity and evolve DCIS significantly faster. However, the more complex progenitor hierarchy structure was able to sustain the rapid reproduction of a cancer cell population for longer periods of time.

  15. The threshold of coexistence and critical behaviour of a predator-prey cellular automaton

    International Nuclear Information System (INIS)

    Arashiro, Everaldo; Tome, Tania

    2007-01-01

    We study a probabilistic cellular automaton to describe two population biology problems: the threshold of species coexistence in a predator-prey system and the spreading of an epidemic in a population. By carrying out mean-field approximations and numerical simulations we obtain the phase boundaries (thresholds) related to the transition between an active state, where prey and predators present a stable coexistence, and a prey absorbing state. The numerical estimates for the critical exponents show that the transition belongs to the directed percolation universality class. In the limit where the cellular automaton maps into a model for the spreading of an epidemic with immunization we observe a crossover from directed percolation class to the dynamic percolation class. Patterns of growing clusters related to species coexistence and spreading of epidemic are shown and discussed

  16. Simulation of Microstructure during Laser Rapid Forming Solidification Based on Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Zhi-jian Wang

    2014-01-01

    Full Text Available The grain microstructure of molten pool during the solidification of TC4 titanium alloy in the single point laser cladding was investigated based on the CAFE model which is the cellular automaton (CA coupled with the finite element (FE method. The correct temperature field is the prerequisite for simulating the grain microstructure during the solidification of the molten pool. The model solves the energy equation by the FE method to simulate the temperature distribution in the molten pool of the single point laser cladding. Based on the temperature field, the solidification microstructure of the molten pool is also simulated with the CAFE method. The results show that the maximum temperature in the molten pool increases with the laser power and the scanning rate. The laser power has a larger influence on the temperature distribution of the molten pool than the scanning rate. During the solidification of the molten pool, the heat at the bottom of the molten pool transfers faster than that at the top of the molten pool. The grains rapidly grow into the molten pool, and then the columnar crystals are formed. This study has a very important significance for improving the quality of the structure parts manufactured through the laser cladding forming.

  17. Soliton cellular automaton associated with Dn(1)-crystal B2,s

    Science.gov (United States)

    Misra, Kailash C.; Wilson, Evan A.

    2013-04-01

    A solvable vertex model in ferromagnetic regime gives rise to a soliton cellular automaton which is a discrete dynamical system in which site variables take on values in a finite set. We study the scattering of a class of soliton cellular automata associated with the U_q(D_n^{(1)})-perfect crystal B2, s. We calculate the combinatorial R matrix for all elements of B2, s ⊗ B2, 1. In particular, we show that the scattering rule for our soliton cellular automaton can be identified with the combinatorial R matrix for U_q(A_1^{(1)}) oplus U_q(D_{n-2}^{(1)})-crystals.

  18. Modeling and Experimental Study of Soft Error Propagation Based on Cellular Automaton

    OpenAIRE

    He, Wei; Wang, Yueke; Xing, Kefei; Yang, Jianwei

    2016-01-01

    Aiming to estimate SEE soft error performance of complex electronic systems, a soft error propagation model based on cellular automaton is proposed and an estimation methodology based on circuit partitioning and error propagation is presented. Simulations indicate that different fault grade jamming and different coupling factors between cells are the main parameters influencing the vulnerability of the system. Accelerated radiation experiments have been developed to determine the main paramet...

  19. Reaction-diffusion path planning in a hybrid chemical and cellular-automaton processor

    International Nuclear Information System (INIS)

    Adamatzky, Andrew; Lacy Costello, Benjamin de

    2003-01-01

    To find the shortest collision-free path in a room containing obstacles we designed a chemical processor and coupled it with a cellular-automaton processor. In the chemical processor obstacles are represented by sites of high concentration of potassium iodide and a planar substrate is saturated with palladium chloride. Potassium iodide diffuses into the substrate and reacts with palladium chloride. A dark coloured precipitate of palladium iodide is formed almost everywhere except sites where two or more diffusion wavefronts collide. The less coloured sites are situated at the furthest distance from obstacles. Thus, the chemical processor develops a repulsive field, generated by obstacles. A snapshot of the chemical processor is inputted to a cellular automaton. The automaton behaves like a discrete excitable media; also, every cell of the automaton is supplied with a pointer that shows an origin of the cell's excitation. The excitation spreads along the cells corresponding to precipitate depleted sites of the chemical processor. When the destination-site is excited, waves travel on the lattice and update the orientations of the pointers. Thus, the automaton constructs a spanning tree, made of pointers, that guides a traveler towards the destination point. Thus, the automaton medium generates an attractive field and combination of this attractive field with the repulsive field, generated by the chemical processor, provides us with a solution of the collision-free path problem

  20. Cellular automaton modeling of biological pattern formation characterization, examples, and analysis

    CERN Document Server

    Deutsch, Andreas

    2017-01-01

    This text explores the use of cellular automata in modeling pattern formation in biological systems. It describes several mathematical modeling approaches utilizing cellular automata that can be used to study the dynamics of interacting cell systems both in simulation and in practice. New in this edition are chapters covering cell migration, tissue development, and cancer dynamics, as well as updated references and new research topic suggestions that reflect the rapid development of the field. The book begins with an introduction to pattern-forming principles in biology and the various mathematical modeling techniques that can be used to analyze them. Cellular automaton models are then discussed in detail for different types of cellular processes and interactions, including random movement, cell migration, adhesive cell interaction, alignment and cellular swarming, growth processes, pigment cell pattern formation, tissue development, tumor growth and invasion, and Turing-type patterns and excitable media. In ...

  1. An outline of cellular automaton universe via cosmological KdV equation

    Science.gov (United States)

    Christianto, V.; Smarandache, F.; Umniyati, Y.

    2018-03-01

    It has been known for long time that the cosmic sound wave was there since the early epoch of the Universe. Signatures of its existence are abound. However, such a sound wave model of cosmology is rarely developed fully into a complete framework. This paper can be considered as our second attempt towards such a complete description of the Universe based on soliton wave solution of cosmological KdV equation. Then we advance further this KdV equation by virtue of Cellular Automaton method to solve the PDEs. We submit wholeheartedly Robert Kuruczs hypothesis that Big Bang should be replaced with a finite cellular automaton universe with no expansion [4][5]. Nonetheless, we are fully aware that our model is far from being complete, but it appears the proposed cellular automaton model of the Universe is very close in spirit to what Konrad Zuse envisaged long time ago. It is our hope that the new proposed method can be verified with observation data. But we admit that our model is still in its infancy, more researches are needed to fill all the missing details.

  2. Update schemes of multi-velocity floor field cellular automaton for pedestrian dynamics

    Science.gov (United States)

    Luo, Lin; Fu, Zhijian; Cheng, Han; Yang, Lizhong

    2018-02-01

    Modeling pedestrian movement is an interesting problem both in statistical physics and in computational physics. Update schemes of cellular automaton (CA) models for pedestrian dynamics govern the schedule of pedestrian movement. Usually, different update schemes make the models behave in different ways, which should be carefully recalibrated. Thus, in this paper, we investigated the influence of four different update schemes, namely parallel/synchronous scheme, random scheme, order-sequential scheme and shuffled scheme, on pedestrian dynamics. The multi-velocity floor field cellular automaton (FFCA) considering the changes of pedestrians' moving properties along walking paths and heterogeneity of pedestrians' walking abilities was used. As for parallel scheme only, the collisions detection and resolution should be considered, resulting in a great difference from any other update schemes. For pedestrian evacuation, the evacuation time is enlarged, and the difference in pedestrians' walking abilities is better reflected, under parallel scheme. In face of a bottleneck, for example a exit, using a parallel scheme leads to a longer congestion period and a more dispersive density distribution. The exit flow and the space-time distribution of density and velocity have significant discrepancies under four different update schemes when we simulate pedestrian flow with high desired velocity. Update schemes may have no influence on pedestrians in simulation to create tendency to follow others, but sequential and shuffled update scheme may enhance the effect of pedestrians' familiarity with environments.

  3. Multiscale Simulation of Porous Ceramics Based on Movable Cellular Automaton Method

    Science.gov (United States)

    Smolin, A.; Smolin, I.; Eremina, G.; Smolina, I.

    2017-10-01

    The paper presents a model for simulating mechanical behaviour of multiscale porous ceramics based on movable cellular automaton method, which is a novel particle method in computational mechanics of solid. The initial scale of the proposed approach corresponds to the characteristic size of the smallest pores in the ceramics. At this scale, we model uniaxial compression of several representative samples with an explicit account of pores of the same size but with the random unique position in space. As a result, we get the average values of Young’s modulus and strength, as well as the parameters of the Weibull distribution of these properties at the current scale level. These data allow us to describe the material behaviour at the next scale level were only the larger pores are considered explicitly, while the influence of small pores is included via the effective properties determined at the previous scale level. If the pore size distribution function of the material has N maxima we need to perform computations for N - 1 levels in order to get the properties from the lowest scale up to the macroscale step by step. The proposed approach was applied to modelling zirconia ceramics with bimodal pore size distribution. The obtained results show correct behaviour of the model sample at the macroscale.

  4. Solutions of the lattice sine–Gordon equation and the solitons of its cellular automaton

    International Nuclear Information System (INIS)

    Willox, R; Ramani, A; Grammaticos, B

    2014-01-01

    We analyse the solutions of the cellular automaton sine–Gordon equation and link them to solutions of the discrete, lattice, sine–Gordon. We show that while the ultradiscretizable, positive definite, solutions of the latter behave dispersively, certain parts of these dispersive waves nonetheless survive in the ultradiscrete limit, giving rise to the solutions of the cellular automaton. We examine the ultradiscrete solutions in the case of a generalized cellular automaton in which the dependent variable can assume non-integer values and we show that the collision of two solitary waves is inelastic, leading to the creation of a ‘bridge’ of constant height that links two outgoing structures. Based on the ultradiscrete form of the sine–Gordon equation we explain the appearance of this bridging region and we describe its interaction with a solitary wave. (paper)

  5. Simulation of glioblastoma multiforme (GBM) tumor cells using ising model on the Creutz Cellular Automaton

    Science.gov (United States)

    Züleyha, Artuç; Ziya, Merdan; Selçuk, Yeşiltaş; Kemal, Öztürk M.; Mesut, Tez

    2017-11-01

    Computational models for tumors have difficulties due to complexity of tumor nature and capacities of computational tools, however, these models provide visions to understand interactions between tumor and its micro environment. Moreover computational models have potential to develop strategies for individualized treatments for cancer. To observe a solid brain tumor, glioblastoma multiforme (GBM), we present a two dimensional Ising Model applied on Creutz cellular automaton (CCA). The aim of this study is to analyze avascular spherical solid tumor growth, considering transitions between non tumor cells and cancer cells are like phase transitions in physical system. Ising model on CCA algorithm provides a deterministic approach with discrete time steps and local interactions in position space to view tumor growth as a function of time. Our simulation results are given for fixed tumor radius and they are compatible with theoretical and clinic data.

  6. Simulation of diffusion in a two-dimensional lattice gas cellular automaton: a test of mode-coupling theory

    NARCIS (Netherlands)

    Frenkel, D.; Ernst, M.H.

    1989-01-01

    We compute the velocity autocorrelation function of a tagged particle in a two-dimensional lattice-gas cellular automaton using a method that is about a million times more efficient than existing techniques. A t-1 algebraic tail in the tagged-particle velocity autocorrelation function is clearly

  7. Modeling and Experimental Study of Soft Error Propagation Based on Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Wei He

    2016-01-01

    Full Text Available Aiming to estimate SEE soft error performance of complex electronic systems, a soft error propagation model based on cellular automaton is proposed and an estimation methodology based on circuit partitioning and error propagation is presented. Simulations indicate that different fault grade jamming and different coupling factors between cells are the main parameters influencing the vulnerability of the system. Accelerated radiation experiments have been developed to determine the main parameters for raw soft error vulnerability of the module and coupling factors. Results indicate that the proposed method is feasible.

  8. Application of a cellular automaton for recognition of straight tracks in the spectrometer DISTO

    International Nuclear Information System (INIS)

    Bussa, M.P.; Fava, L.; Ferrero, L.; Grasso, A.; Ivanov, V.V.; Kisel', I.V.; Konotopskaya, E.V.; Pontecorvo, G.B.

    1995-01-01

    A model of the cellular automaton for recognition of straight tracks has been developed. The program realization of this algorithm has shown high efficiency and speed for the simulated data for the experiment DISTO. Its working speed provides for the processing of approximately 1000 events/sec using the 50 MIPS RISC-processor. This makes suitable its application for track recognition in the second level trigger of the DISTO spectrometer. 10 refs., 7 figs., 1 tab

  9. Cellular automaton model of coupled mass transport and chemical reactions

    International Nuclear Information System (INIS)

    Karapiperis, T.

    1994-01-01

    Mass transport, coupled with chemical reactions, is modelled as a cellular automaton in which solute molecules perform a random walk on a lattice and react according to a local probabilistic rule. Assuming molecular chaos and a smooth density function, we obtain the standard reaction-transport equations in the continuum limit. The model is applied to the reactions a + b ↔c and a + b →c, where we observe interesting macroscopic effects resulting from microscopic fluctuations and spatial correlations between molecules. We also simulate autocatalytic reaction schemes displaying spontaneous formation of spatial concentration patterns. Finally, we propose and discuss the limitations of a simple model for mineral-solute interaction. (author) 5 figs., 20 refs

  10. Cellular automaton model in the fundamental diagram approach reproducing the synchronized outflow of wide moving jams

    International Nuclear Information System (INIS)

    Tian, Jun-fang; Yuan, Zhen-zhou; Jia, Bin; Fan, Hong-qiang; Wang, Tao

    2012-01-01

    Velocity effect and critical velocity are incorporated into the average space gap cellular automaton model [J.F. Tian, et al., Phys. A 391 (2012) 3129], which was able to reproduce many spatiotemporal dynamics reported by the three-phase theory except the synchronized outflow of wide moving jams. The physics of traffic breakdown has been explained. Various congested patterns induced by the on-ramp are reproduced. It is shown that the occurrence of synchronized outflow, free outflow of wide moving jams is closely related with drivers time delay in acceleration at the downstream jam front and the critical velocity, respectively. -- Highlights: ► Velocity effect is added into average space gap cellular automaton model. ► The physics of traffic breakdown has been explained. ► The probabilistic nature of traffic breakdown is simulated. ► Various congested patterns induced by the on-ramp are reproduced. ► The occurrence of synchronized outflow of jams depends on drivers time delay.

  11. Simulating bi-directional pedestrian flow in a cellular automaton model considering the body-turning behavior

    Science.gov (United States)

    Jin, Cheng-Jie; Jiang, Rui; Yin, Jun-Lin; Dong, Li-Yun; Li, Dawei

    2017-09-01

    In the experiments of bi-directional pedestrian flow, it is often observed that pedestrians turn their bodies and change from walking straight to walking sideways, in order to mitigate or avoid the conflicts with opposite walking ones. When these conflicts disappear, pedestrians restore and walk straight again. In the turning states, the forward velocities of pedestrians are not affected. In order to simulate this body-turning behavior, we use a cellular automaton (CA) model named ITP model, which has been proposed before. But the occupied area of one pedestrian is set as 0.4 m∗0.2 m. After the introduction of new rules of turnings and restorations, the pedestrians become more intelligent and flexible during the lane formation process, and some improvements of the fundamental diagram of pedestrian flow can be found. The simulation results of two different scenarios under open boundary conditions are also presented, and compared with the experimental data. It is shown that the new model performs much better than the original model in various tests, which further confirms the validity of the new rules. We think this approach is one useful contribution to the pedestrian flow modeling.

  12. Application of a novel cellular automaton porosity prediction model to aluminium castings

    International Nuclear Information System (INIS)

    Atwood, R.C.; Chirazi, A.; Lee, P.D.

    2002-01-01

    A multiscale model was developed to predict the formation of porosity within a solidifying aluminium-silicon alloy. The diffusion of silicon and dissolved gas was simulated on a microscopic scale combined with cellular automaton models of gas porosity formation within the growing three-dimensional solidification microstructure. However, due to high computational cost, the modelled volume is limited to the millimetre range. This renders the application of direct modelling of complex shape castings unfeasible. Combining the microstructural modelling with a statistical response-surface prediction method allows application of the microstructural model results to industrial scale casts by incorporating them in commercial solidification software. (author)

  13. Cellular Automaton Modeling of Dendritic Growth Using a Multi-grid Method

    International Nuclear Information System (INIS)

    Natsume, Y; Ohsasa, K

    2015-01-01

    A two-dimensional cellular automaton model with a multi-grid method was developed to simulate dendritic growth. In the present model, we used a triple-grid system for temperature, solute concentration and solid fraction fields as a new approach of the multi-grid method. In order to evaluate the validity of the present model, we carried out simulations of single dendritic growth, secondary dendrite arm growth, multi-columnar dendritic growth and multi-equiaxed dendritic growth. From the results of the grid dependency from the simulation of single dendritic growth, we confirmed that the larger grid can be used in the simulation and that the computational time can be reduced dramatically. In the simulation of secondary dendrite arm growth, the results from the present model were in good agreement with the experimental data and the simulated results from a phase-field model. Thus, the present model can quantitatively simulate dendritic growth. From the simulated results of multi-columnar and multi-equiaxed dendrites, we confirmed that the present model can perform simulations under practical solidification conditions. (paper)

  14. Detector independent cellular automaton algorithm for track reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Kisel, Ivan; Kulakov, Igor; Zyzak, Maksym [Goethe Univ. Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany); Collaboration: CBM-Collaboration

    2013-07-01

    Track reconstruction is one of the most challenging problems of data analysis in modern high energy physics (HEP) experiments, which have to process per second of the order of 10{sup 7} events with high track multiplicity and density, registered by detectors of different types and, in many cases, located in non-homogeneous magnetic field. Creation of reconstruction package common for all experiments is considered to be important in order to consolidate efforts. The cellular automaton (CA) track reconstruction approach has been used successfully in many HEP experiments. It is very simple, efficient, local and parallel. Meanwhile it is intrinsically independent of detector geometry and good candidate for common track reconstruction. The CA implementation for the CBM experiment has been generalized and applied to the ALICE ITS and STAR HFT detectors. Tests with simulated collisions have been performed. The track reconstruction efficiencies are at the level of 95% for majority of the signal tracks for all detectors.

  15. Development of a formalism of movable cellular automaton method for numerical modeling of fracture of heterogeneous elastic-plastic materials

    Directory of Open Access Journals (Sweden)

    S. Psakhie

    2013-04-01

    Full Text Available A general approach to realization of models of elasticity, plasticity and fracture of heterogeneous materials within the framework of particle-based numerical methods is proposed in the paper. It is based on building many-body forces of particle interaction, which provide response of particle ensemble correctly conforming to the response (including elastic-plastic behavior and fracture of simulated solids. Implementation of proposed approach within particle-based methods is demonstrated by the example of the movable cellular automaton (MCA method, which integrates the possibilities of particle-based discrete element method (DEM and cellular automaton methods. Emergent advantages of the developed approach to formulation of many-body interaction are discussed. Main of them are its applicability to various realizations of the concept of discrete elements and a possibility to realize various rheological models (including elastic-plastic or visco-elastic-plastic and models of fracture to study deformation and fracture of solid-phase materials and media. Capabilities of particle-based modeling of heterogeneous solids are demonstrated by the problem of simulation of deformation and fracture of particle-reinforced metal-ceramic composites.

  16. Emergent 1d Ising Behavior in AN Elementary Cellular Automaton Model

    Science.gov (United States)

    Kassebaum, Paul G.; Iannacchione, Germano S.

    The fundamental nature of an evolving one-dimensional (1D) Ising model is investigated with an elementary cellular automaton (CA) simulation. The emergent CA simulation employs an ensemble of cells in one spatial dimension, each cell capable of two microstates interacting with simple nearest-neighbor rules and incorporating an external field. The behavior of the CA model provides insight into the dynamics of coupled two-state systems not expressible by exact analytical solutions. For instance, state progression graphs show the causal dynamics of a system through time in relation to the system's entropy. Unique graphical analysis techniques are introduced through difference patterns, diffusion patterns, and state progression graphs of the 1D ensemble visualizing the evolution. All analyses are consistent with the known behavior of the 1D Ising system. The CA simulation and new pattern recognition techniques are scalable (in both dimension, complexity, and size) and have many potential applications such as complex design of materials, control of agent systems, and evolutionary mechanism design.

  17. Cellular automaton simulation of the diffusive motion of bacteria and their adhesion to nanostructures on a solid surface.

    Science.gov (United States)

    Yamamoto, Takehiro; Emura, Chie; Oya, Masashi

    2016-12-01

    The growth of a biofilm begins with the adhesion of bacteria to a solid surface. Consequently, biofilm growth can be managed by the control of bacterial adhesion. Recent experimental studies have suggested that bacterial adhesion can be controlled by modifying a solid surface using nanostructures. Computational prediction and analysis of bacterial adhesion behavior are expected to be useful for the design of effective arrangements of nanostructures for controlling bacterial adhesion. The present study developed a cellular automaton (CA) model for bacterial adhesion simulation that could describe both the diffusive motion of bacteria and dependence of their adhesion patterns on the distance between nanostructures observed in experimental studies. The diffusive motion was analyzed by the moment scaling spectrum theory, and the present model was confirmed to describe subdiffusion behavior due to obstacles. Adhesion patterns observed in experimental studies can be successfully simulated by introducing CA rules to describe a mechanism by which bacteria tend to move to increase the area of contact with nanostructures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Pseudo-random number generation using a 3-state cellular automaton

    Science.gov (United States)

    Bhattacharjee, Kamalika; Paul, Dipanjyoti; Das, Sukanta

    This paper investigates the potentiality of pseudo-random number generation of a 3-neighborhood 3-state cellular automaton (CA) under periodic boundary condition. Theoretical and empirical tests are performed on the numbers, generated by the CA, to observe the quality of it as pseudo-random number generator (PRNG). We analyze the strength and weakness of the proposed PRNG and conclude that the selected CA is a good random number generator.

  19. A Modified Cellular Automaton Approach for Mixed Bicycle Traffic Flow Modeling

    Directory of Open Access Journals (Sweden)

    Xiaonian Shan

    2015-01-01

    Full Text Available Several previous studies have used the Cellular Automaton (CA for the modeling of bicycle traffic flow. However, previous CA models have several limitations, resulting in differences between the simulated and the observed traffic flow features. The primary objective of this study is to propose a modified CA model for simulating the characteristics of mixed bicycle traffic flow. Field data were collected on physically separated bicycle path in Shanghai, China, and were used to calibrate the CA model using the genetic algorithm. Traffic flow features between simulations of several CA models and field observations were compared. The results showed that our modified CA model produced more accurate simulation for the fundamental diagram and the passing events in mixed bicycle traffic flow. Based on our model, the bicycle traffic flow features, including the fundamental diagram, the number of passing events, and the number of lane changes, were analyzed. We also analyzed the traffic flow features with different traffic densities, traffic components on different travel lanes. Results of the study can provide important information for understanding and simulating the operations of mixed bicycle traffic flow.

  20. Cellular automaton model of mass transport with chemical reactions

    International Nuclear Information System (INIS)

    Karapiperis, T.; Blankleider, B.

    1993-10-01

    The transport and chemical reactions of solutes are modelled as a cellular automaton in which molecules of different species perform a random walk on a regular lattice and react according to a local probabilistic rule. The model describes advection and diffusion in a simple way, and as no restriction is placed on the number of particles at a lattice site, it is also able to describe a wide variety of chemical reactions. Assuming molecular chaos and a smooth density function, we obtain the standard reaction-transport equations in the continuum limit. Simulations on one-and two-dimensional lattices show that the discrete model can be used to approximate the solutions of the continuum equations. We discuss discrepancies which arise from correlations between molecules and how these discrepancies disappear as the continuum limit is approached. Of particular interest are simulations displaying long-time behaviour which depends on long-wavelength statistical fluctuations not accounted for by the standard equations. The model is applied to the reactions a + b ↔ c and a + b → c with homogeneous and inhomogeneous initial conditions as well as to systems subject to autocatalytic reactions and displaying spontaneous formation of spatial concentration patterns. (author) 9 figs., 34 refs

  1. Cellular automaton decoders of topological quantum memories in the fault tolerant setting

    International Nuclear Information System (INIS)

    Herold, Michael; Eisert, Jens; Kastoryano, Michael J; Campbell, Earl T

    2017-01-01

    Active error decoding and correction of topological quantum codes—in particular the toric code—remains one of the most viable routes to large scale quantum information processing. In contrast, passive error correction relies on the natural physical dynamics of a system to protect encoded quantum information. However, the search is ongoing for a completely satisfactory passive scheme applicable to locally interacting two-dimensional systems. Here, we investigate dynamical decoders that provide passive error correction by embedding the decoding process into local dynamics. We propose a specific discrete time cellular-automaton decoder in the fault tolerant setting and provide numerical evidence showing that the logical qubit has a survival time extended by several orders of magnitude over that of a bare unencoded qubit. We stress that (asynchronous) dynamical decoding gives rise to a Markovian dissipative process. We hence equate cellular-automaton decoding to a fully dissipative topological quantum memory, which removes errors continuously. In this sense, uncontrolled and unwanted local noise can be corrected for by a controlled local dissipative process. We analyze the required resources, commenting on additional polylogarithmic factors beyond those incurred by an ideal constant resource dynamical decoder. (paper)

  2. Cellular automaton and elastic net for event reconstruction in the NEMO-2 experiment

    International Nuclear Information System (INIS)

    Kovalenko, V.

    1997-01-01

    A cellular automaton for track searching and an elastic net for charged particle trajectory fitting are presented. The advantages of the methods are: simplicity of the algorithms, fast and stable convergence to real tracks, and a reconstruction efficiency close to 100%. Demonstration programs are available at http://nuweb.jinr.dubna.su/LNP/NEMO using a Java enabled browser. (orig.)

  3. Deterministic one-way simulation of two-way, real-time cellular automata and its related problems

    Energy Technology Data Exchange (ETDEWEB)

    Umeo, H; Morita, K; Sugata, K

    1982-06-13

    The authors show that for any deterministic two-way, real-time cellular automaton, m, there exists a deterministic one-way cellular automation which can simulate m in twice real-time. Moreover the authors present a new type of deterministic one-way cellular automata, called circular cellular automata, which are computationally equivalent to deterministic two-way cellular automata. 7 references.

  4. Equiaxed and columnar dendrite growth simulation in Al-7Si- Mg ternary alloys using cellular automaton method

    International Nuclear Information System (INIS)

    Chen, Rui; Xu, Qingyan; Liu, Baicheng

    2015-01-01

    In this paper, a modified cellular automaton (MCA) model allowing for the prediction of dendrite growth of Al-Si-Mg ternary alloys in two and three dimensions is presented. The growth kinetic of S/L interface is calculated based on the solute equilibrium approach. In order to describe the dendrite growth with arbitrarily crystallographic orientations, this model introduces a modified decentered octahedron algorithm for neighborhood tracking to eliminate the effect of mesh dependency on dendrite growth. The thermody namic and kinetic data needed for dendrite growth is obtained through coupling with Pandat software package in combination with thermodynamic/kinetic/equilibrium phase diagram calculation databases. The effect of interactions between various alloying elements on solute diffusion coefficient is considered in the model. This model has first been used to simulate Al-7Si (weight percent) binary dendrite growth followed by a validation using theoretical predictions. For ternary alloy, Al-7Si-0.5Mg dendrite simulation has been carried out and the effects of solute interactions on diffusion matrix as well as the differences of Si and Mg in solute distribution have been analyzed. For actual application, this model has been applied to simulate the equiaxed dendrite growth with various crystallographic orientations of Al-7Si-0.36Mg ternary alloy, and the predicted secondary dendrite arm spacing (SDAS) shows a reasonable agreement with the experimental ones. Furthermore, the columnar dendrite growth in directional solidification has also been simulated and the predicted primary dendrite arm spacing (PDAS) is in good agreement with experiments. The simulated results effectively demonstrate the abilities of the model in prediction of dendritic microstructure of Al-Si-Mg ternary alloy. (paper)

  5. Equiaxed and columnar dendrite growth simulation in Al-7Si- Mg ternary alloys using cellular automaton method

    Science.gov (United States)

    Chen, Rui; Xu, Qingyan; Liu, Baicheng

    2015-06-01

    In this paper, a modified cellular automaton (MCA) model allowing for the prediction of dendrite growth of Al-Si-Mg ternary alloys in two and three dimensions is presented. The growth kinetic of S/L interface is calculated based on the solute equilibrium approach. In order to describe the dendrite growth with arbitrarily crystallographic orientations, this model introduces a modified decentered octahedron algorithm for neighborhood tracking to eliminate the effect of mesh dependency on dendrite growth. The thermody namic and kinetic data needed for dendrite growth is obtained through coupling with Pandat software package in combination with thermodynamic/kinetic/equilibrium phase diagram calculation databases. The effect of interactions between various alloying elements on solute diffusion coefficient is considered in the model. This model has first been used to simulate Al-7Si (weight percent) binary dendrite growth followed by a validation using theoretical predictions. For ternary alloy, Al-7Si-0.5Mg dendrite simulation has been carried out and the effects of solute interactions on diffusion matrix as well as the differences of Si and Mg in solute distribution have been analyzed. For actual application, this model has been applied to simulate the equiaxed dendrite growth with various crystallographic orientations of Al-7Si-0.36Mg ternary alloy, and the predicted secondary dendrite arm spacing (SDAS) shows a reasonable agreement with the experimental ones. Furthermore, the columnar dendrite growth in directional solidification has also been simulated and the predicted primary dendrite arm spacing (PDAS) is in good agreement with experiments. The simulated results effectively demonstrate the abilities of the model in prediction of dendritic microstructure of Al-Si-Mg ternary alloy.

  6. Application of a cellular automaton for the evolution of etched nuclear tracks

    International Nuclear Information System (INIS)

    Cruz-Trujillo, Leonardo de la; Hernández-Hernández, C.; Vázquez-López, C.; Zendejas-Leal, B.E.; Golzarri, I.; Espinosa, G.

    2013-01-01

    In the present work, it is demonstrated the first application of cellular automata to the growing of etched nuclear tracks. The simplest case in which conical etched tracks are gradually formed is presented, as well as a general case of time varying etching rate V t . It is demonstrated that the cellular automata elements consist in an image pattern of the latent nuclear track input cells, 16 rules for updating states, the Moore neighborhood and an algorithm of four states. - Highlights: ► We model the evolution of an etched nuclear track using cellular automata (ca). ► A cellular automaton of a conical track has 4 states and 16 transition rules. ► The ca of general tracks require a not regular mesh and the L(t) and V b parameters

  7. CATS: a cellular automaton for tracking in silicon for the HERA-B vertex detector

    International Nuclear Information System (INIS)

    Abt, I.; Emeliyanov, D.; Kisel, I.; Masciocchi, S.

    2002-01-01

    The new track reconstruction program CATS developed for the Vertex Detector System of the HERA-B experiment at DESY is presented. It employs a cellular automaton for track searching and the Kalman filter for track fitting. This results in a very fast algorithm that combines highly efficient track recognition with accurate and reliable track parameter estimation. To reduce the computational cost of the fit an optimized numerical implementation of the Kalman filter is used. Alternative approaches to the track reconstruction in the VDS are also discussed. Since 1999, after extensive tests on simulated data, CATS has been employed to reconstruct experimental data collected in HERA-B. Results regarding tracking performance, the accuracy of track parameter estimates and CPU time consumption are presented

  8. Non-linearity and spatial resolution in a cellular automaton model of a small upland basin

    Directory of Open Access Journals (Sweden)

    T. J. Coulthard

    1998-01-01

    Full Text Available The continuing development of computational fluid dynamics is allowing the high resolution study of hydraulic and sediment transport processes but, due to computational complexities, these are rarely applied to areas larger than a reach. Existing approaches, based upon linked cross sections, can give a quasi two-dimensional view, effectively simulating sediment transport for a single river reach. However, a basin represents a whole discrete dynamic system within which channel, floodplain and slope processes operate over a wide range of space and time scales. Here, a cellular automaton (CA approach has been used to overcome some of these difficulties, in which the landscape is represented as a series of fixed size cells. For every model iteration, each cell acts only in relation to the influence of its immediate neighbours in accordance with appropriate rules. The model presented here takes approximations of existing flow and sediment transport equations, and integrates them, together with slope and floodplain approximations, within a cellular automaton framework. This method has been applied to the basin of Cam Gill Beck (4.2 km2 above Starbotton, upper Wharfedale, a tributary of the River Wharfe, North Yorkshire, UK. This approach provides, for the first time, a workable model of the whole basin at a 1 m resolution. Preliminary results show the evolution of bars, braids, terraces and alluvial fans which are similar to those observed in the field, and examples of large and small scale non-linear behaviour which may have considerable implications for future models.

  9. Cellular automaton and elastic net for event reconstruction in the NEMO-2 experiment

    International Nuclear Information System (INIS)

    Kisel, I.; Kovalenko, V.; Laplanche, F.

    1997-01-01

    A cellular automaton for track searching combined with an elastic net for charged particle trajectory fitting is presented. The advantages of the methods are: the simplicity of the algorithms, the fast and stable convergency to real tracks, and a good reconstruction efficiency. The combination of techniques have been used with success for event reconstruction on the data of the NEMO-2 double-beta (ββ) decay experiments. (orig.)

  10. Cellular automaton modelling of ductile iron microstructure in the thin wall casting

    International Nuclear Information System (INIS)

    Burbelko, A A; Gurgul, D; Kapturkiewicz, W; Górny, M

    2012-01-01

    The mathematical model of the globular eutectic solidification in 2D was designed. Proposed model is based on the Cellular Automaton Finite Differences (CA-FD) calculation method. Model has been used for studies of the primary austenite and of globular eutectic grains growth during the ductile iron solidification in the thin wall casting. Model takes into account, among other things, non-uniform temperature distribution in the casting wall cross-section, kinetics of the austenite and graphite grains nucleation, and non-equilibrium nature of the interphase boundary migration.

  11. Motzkin numbers out of Random Domino Automaton

    Energy Technology Data Exchange (ETDEWEB)

    Białecki, Mariusz, E-mail: bialecki@igf.edu.pl [Institute of Geophysics, Polish Academy of Sciences, ul. Ks. Janusza 64, 01-452 Warszawa (Poland)

    2012-10-01

    Motzkin numbers are derived from a special case of Random Domino Automaton – recently proposed a slowly driven system being a stochastic toy model of earthquakes. It is also a generalisation of 1D Drossel–Schwabl forest-fire model. A solution of the set of equations describing stationary state of Random Domino Automaton in inverse-power case is presented. A link with Motzkin numbers allows to present explicit form of asymptotic behaviour of the automaton. -- Highlights: ► Motzkin numbers are derived from stochastic cellular automaton with avalanches. ► Explicit solution of toy model of earthquakes is presented. ► Case with inverse-power distribution of avalanches is found.

  12. A parallelized three-dimensional cellular automaton model for grain growth during additive manufacturing

    Science.gov (United States)

    Lian, Yanping; Lin, Stephen; Yan, Wentao; Liu, Wing Kam; Wagner, Gregory J.

    2018-05-01

    In this paper, a parallelized 3D cellular automaton computational model is developed to predict grain morphology for solidification of metal during the additive manufacturing process. Solidification phenomena are characterized by highly localized events, such as the nucleation and growth of multiple grains. As a result, parallelization requires careful treatment of load balancing between processors as well as interprocess communication in order to maintain a high parallel efficiency. We give a detailed summary of the formulation of the model, as well as a description of the communication strategies implemented to ensure parallel efficiency. Scaling tests on a representative problem with about half a billion cells demonstrate parallel efficiency of more than 80% on 8 processors and around 50% on 64; loss of efficiency is attributable to load imbalance due to near-surface grain nucleation in this test problem. The model is further demonstrated through an additive manufacturing simulation with resulting grain structures showing reasonable agreement with those observed in experiments.

  13. A parallelized three-dimensional cellular automaton model for grain growth during additive manufacturing

    Science.gov (United States)

    Lian, Yanping; Lin, Stephen; Yan, Wentao; Liu, Wing Kam; Wagner, Gregory J.

    2018-01-01

    In this paper, a parallelized 3D cellular automaton computational model is developed to predict grain morphology for solidification of metal during the additive manufacturing process. Solidification phenomena are characterized by highly localized events, such as the nucleation and growth of multiple grains. As a result, parallelization requires careful treatment of load balancing between processors as well as interprocess communication in order to maintain a high parallel efficiency. We give a detailed summary of the formulation of the model, as well as a description of the communication strategies implemented to ensure parallel efficiency. Scaling tests on a representative problem with about half a billion cells demonstrate parallel efficiency of more than 80% on 8 processors and around 50% on 64; loss of efficiency is attributable to load imbalance due to near-surface grain nucleation in this test problem. The model is further demonstrated through an additive manufacturing simulation with resulting grain structures showing reasonable agreement with those observed in experiments.

  14. A Cellular Automata-based Model for Simulating Restitution Property in a Single Heart Cell.

    Science.gov (United States)

    Sabzpoushan, Seyed Hojjat; Pourhasanzade, Fateme

    2011-01-01

    Ventricular fibrillation is the cause of the most sudden mortalities. Restitution is one of the specific properties of ventricular cell. The recent findings have clearly proved the correlation between the slope of restitution curve with ventricular fibrillation. This; therefore, mandates the modeling of cellular restitution to gain high importance. A cellular automaton is a powerful tool for simulating complex phenomena in a simple language. A cellular automaton is a lattice of cells where the behavior of each cell is determined by the behavior of its neighboring cells as well as the automata rule. In this paper, a simple model is depicted for the simulation of the property of restitution in a single cardiac cell using cellular automata. At first, two state variables; action potential and recovery are introduced in the automata model. In second, automata rule is determined and then recovery variable is defined in such a way so that the restitution is developed. In order to evaluate the proposed model, the generated restitution curve in our study is compared with the restitution curves from the experimental findings of valid sources. Our findings indicate that the presented model is not only capable of simulating restitution in cardiac cell, but also possesses the capability of regulating the restitution curve.

  15. Simulation of plant communities with a cellular automaton

    Energy Technology Data Exchange (ETDEWEB)

    Gassmann, F [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    With a modelling approach based on cellular automata, five observed types of plant development can be simulated. In addition, the proposed model shows a strong tendency towards the formation of patches and a high degree of dynamical and structural instability leading to limits of predictability for the asymptotic solution chosen by the system among several possible metastable patterns (multistability). Further, external fluctuations can be shown to have advantages for certain plant types. The presented model unifies the fundamental dichotomy in vegetation dynamics between determinism (understood as predictability) and disorder (chance effects) by showing the outcome of both classical theories as special cases. (author) 2 figs., 4 refs.

  16. A cellular automaton - finite volume method for the simulation of dendritic and eutectic growth in binary alloys using an adaptive mesh refinement

    Science.gov (United States)

    Dobravec, Tadej; Mavrič, Boštjan; Šarler, Božidar

    2017-11-01

    A two-dimensional model to simulate the dendritic and eutectic growth in binary alloys is developed. A cellular automaton method is adopted to track the movement of the solid-liquid interface. The diffusion equation is solved in the solid and liquid phases by using an explicit finite volume method. The computational domain is divided into square cells that can be hierarchically refined or coarsened using an adaptive mesh based on the quadtree algorithm. Such a mesh refines the regions of the domain near the solid-liquid interface, where the highest concentration gradients are observed. In the regions where the lowest concentration gradients are observed the cells are coarsened. The originality of the work is in the novel, adaptive approach to the efficient and accurate solution of the posed multiscale problem. The model is verified and assessed by comparison with the analytical results of the Lipton-Glicksman-Kurz model for the steady growth of a dendrite tip and the Jackson-Hunt model for regular eutectic growth. Several examples of typical microstructures are simulated and the features of the method as well as further developments are discussed.

  17. A new cellular automaton for signal controlled traffic flow based on driving behaviors

    Science.gov (United States)

    Wang, Yang; Chen, Yan-Yan

    2015-03-01

    The complexity of signal controlled traffic largely stems from the various driving behaviors developed in response to the traffic signal. However, the existing models take a few driving behaviors into account and consequently the traffic dynamics has not been completely explored. Therefore, a new cellular automaton model, which incorporates the driving behaviors typically manifesting during the different stages when the vehicles are moving toward a traffic light, is proposed in this paper. Numerical simulations have demonstrated that the proposed model can produce the spontaneous traffic breakdown and the dissolution of the over-saturated traffic phenomena. Furthermore, the simulation results indicate that the slow-to-start behavior and the inch-forward behavior can foster the traffic breakdown. Particularly, it has been discovered that the over-saturated traffic can be revised to be an under-saturated state when the slow-down behavior is activated after the spontaneous breakdown. Finally, the contributions of the driving behaviors on the traffic breakdown have been examined. Project supported by the National Basic Research Program of China (Grand No. 2012CB723303) and the Beijing Committee of Science and Technology, China (Grand No. Z1211000003120100).

  18. A study of intergranular corrosion of austenitic stainless steel by electrochemical potentiodynamic reactivation, electron back-scattering diffraction and cellular automaton

    Energy Technology Data Exchange (ETDEWEB)

    Yu Xiaofei [Department of Chemistry, Shandong University, Jinan 250100 (China); Chen Shenhao [Department of Chemistry, Shandong University, Jinan 250100 (China); State Key Laboratory for Corrosion and Protection, Shenyang 110016 (China)], E-mail: shchen@sdu.edu.cn; Liu Ying; Ren Fengfeng [Department of Chemistry, Shandong University, Jinan 250100 (China)

    2010-06-15

    The impact of solution and sensitization treatments on the intergranular corrosion (IGC) of austenitic stainless steel (316) was studied by electrochemical potentiodynamic reactivation (EPR) test, and the results showed the degree of sensitization (DOS) decreased as solution treatment temperature and time went up, but it increased as sensitization temperature prolonged. Factors that affected IGC were investigated by field emission scanning electron microscope (FE-SEM) and electron back-scattering diffraction (EBSD). Furthermore, the precipitation evolution of Cr-rich carbides and the distribution of chromium concentration were simulated by cellular automaton (CA), clearly showing the effects of solution and sensitization treatments on IGC.

  19. Simulation of electrochemical processes in cardiac tissue based on cellular automaton

    International Nuclear Information System (INIS)

    Avdeev, S A; Bogatov, N M

    2014-01-01

    A new class of cellular automata using special accumulative function for nonuniformity distribution is presented. Usage of this automata type for simulation of excitable media applied to electrochemical processes in human cardiac tissue is shown

  20. Cellular automaton modeling of ductile iron microstructure in the thin wall

    Directory of Open Access Journals (Sweden)

    A.A. Burbelko

    2011-10-01

    Full Text Available The mathematical model of the globular eutectic solidification in 2D was designed. Proposed model is based on the Cellular Automaton Finite Differences (CA-FD calculation method. Model has been used for studies of the primary austenite and of globular eutectic grains growth during the solidification of the ductile iron with different carbon equivalent in the thin wall casting. Model takes into account, among other things, non-uniform temperature distribution in the casting wall cross-section, kinetics of the austenite and graphite grains nucleation, and non-equilibrium nature of the interphase boundary migration. Solidification of the DI with different carbon equivalents was analyzed. Obtained results were compared with the solidification path calculated by CALPHAD method.

  1. Simple cellular automaton model for traffic breakdown, highway capacity, and synchronized flow

    Science.gov (United States)

    Kerner, Boris S.; Klenov, Sergey L.; Schreckenberg, Michael

    2011-10-01

    We present a simple cellular automaton (CA) model for two-lane roads explaining the physics of traffic breakdown, highway capacity, and synchronized flow. The model consists of the rules “acceleration,” “deceleration,” “randomization,” and “motion” of the Nagel-Schreckenberg CA model as well as “overacceleration through lane changing to the faster lane,” “comparison of vehicle gap with the synchronization gap,” and “speed adaptation within the synchronization gap” of Kerner's three-phase traffic theory. We show that these few rules of the CA model can appropriately simulate fundamental empirical features of traffic breakdown and highway capacity found in traffic data measured over years in different countries, like characteristics of synchronized flow, the existence of the spontaneous and induced breakdowns at the same bottleneck, and associated probabilistic features of traffic breakdown and highway capacity. Single-vehicle data derived in model simulations show that synchronized flow first occurs and then self-maintains due to a spatiotemporal competition between speed adaptation to a slower speed of the preceding vehicle and passing of this slower vehicle. We find that the application of simple dependences of randomization probability and synchronization gap on driving situation allows us to explain the physics of moving synchronized flow patterns and the pinch effect in synchronized flow as observed in real traffic data.

  2. Facilitating arrhythmia simulation: the method of quantitative cellular automata modeling and parallel running

    Directory of Open Access Journals (Sweden)

    Mondry Adrian

    2004-08-01

    Full Text Available Abstract Background Many arrhythmias are triggered by abnormal electrical activity at the ionic channel and cell level, and then evolve spatio-temporally within the heart. To understand arrhythmias better and to diagnose them more precisely by their ECG waveforms, a whole-heart model is required to explore the association between the massively parallel activities at the channel/cell level and the integrative electrophysiological phenomena at organ level. Methods We have developed a method to build large-scale electrophysiological models by using extended cellular automata, and to run such models on a cluster of shared memory machines. We describe here the method, including the extension of a language-based cellular automaton to implement quantitative computing, the building of a whole-heart model with Visible Human Project data, the parallelization of the model on a cluster of shared memory computers with OpenMP and MPI hybrid programming, and a simulation algorithm that links cellular activity with the ECG. Results We demonstrate that electrical activities at channel, cell, and organ levels can be traced and captured conveniently in our extended cellular automaton system. Examples of some ECG waveforms simulated with a 2-D slice are given to support the ECG simulation algorithm. A performance evaluation of the 3-D model on a four-node cluster is also given. Conclusions Quantitative multicellular modeling with extended cellular automata is a highly efficient and widely applicable method to weave experimental data at different levels into computational models. This process can be used to investigate complex and collective biological activities that can be described neither by their governing differentiation equations nor by discrete parallel computation. Transparent cluster computing is a convenient and effective method to make time-consuming simulation feasible. Arrhythmias, as a typical case, can be effectively simulated with the methods

  3. Analyzing the Influence of Mobile Phone Use of Drivers on Traffic Flow Based on an Improved Cellular Automaton Model

    Directory of Open Access Journals (Sweden)

    Yao Xiao

    2015-01-01

    Full Text Available This paper aimed to analyze the influence of drivers’ behavior of phone use while driving on traffic flow, including both traffic efficiency and traffic safety. An improved cellular automaton model was proposed to simulate traffic flow with distracted drivers based on the Nagel-Schreckenberg model. The driving characters of drivers using a phone were first discussed and a value representing the probability to use a phone while driving was put into the CA model. Simulation results showed that traffic flow rate was significantly reduced if some drivers used a phone compared to no phone use. The flow rate and velocity decreased as the proportion of drivers using a phone increased. While, under low density, the risk of traffic decreased first and then increased as the distracted drivers increased, the distracted behavior of drivers, like using a phone, could reduce the flow rate by 5 percent according to the simulation.

  4. Using exploratory regression to identify optimal driving factors for cellular automaton modeling of land use change.

    Science.gov (United States)

    Feng, Yongjiu; Tong, Xiaohua

    2017-09-22

    Defining transition rules is an important issue in cellular automaton (CA)-based land use modeling because these models incorporate highly correlated driving factors. Multicollinearity among correlated driving factors may produce negative effects that must be eliminated from the modeling. Using exploratory regression under pre-defined criteria, we identified all possible combinations of factors from the candidate factors affecting land use change. Three combinations that incorporate five driving factors meeting pre-defined criteria were assessed. With the selected combinations of factors, three logistic regression-based CA models were built to simulate dynamic land use change in Shanghai, China, from 2000 to 2015. For comparative purposes, a CA model with all candidate factors was also applied to simulate the land use change. Simulations using three CA models with multicollinearity eliminated performed better (with accuracy improvements about 3.6%) than the model incorporating all candidate factors. Our results showed that not all candidate factors are necessary for accurate CA modeling and the simulations were not sensitive to changes in statistically non-significant driving factors. We conclude that exploratory regression is an effective method to search for the optimal combinations of driving factors, leading to better land use change models that are devoid of multicollinearity. We suggest identification of dominant factors and elimination of multicollinearity before building land change models, making it possible to simulate more realistic outcomes.

  5. 4D Cellular Automaton Track Finder in the CBM Experiment

    International Nuclear Information System (INIS)

    Akishina, Valentina; Kisel, Ivan

    2016-01-01

    The CBM experiment (FAIR/GSI, Darmstadt, Germany) will focus on the measurement of rare probes at interaction rates up to 10MHz with data flow of up to 1 TB/s. It requires a novel read-out and data-acquisition concept with self-triggered electronics and free-streaming data. In this case resolving different collisions is a non-trivial task and event building must be performed in software online. That requires full online event reconstruction and selection not only in space, but also in time, so-called 4D event building and selection. This is a task of the First-Level Event Selection (FLES). The FLES reconstruction and selection package consists of several modules: track finding, track fitting, short-lived particles finding, event building and event selection. The Cellular Automaton (CA) track finder algorithm was adapted towards time-based reconstruction. In this article, we describe in detail the modification done to the algorithm, as well as the performance of the developed time-based CA approach

  6. Modelling for Near-Surface Transport Dynamics of Hydrogen of Plasma Facing Materials by use of Cellular Automaton

    International Nuclear Information System (INIS)

    Shimura, K.; Terai, T.; Yamawaki, M.

    2003-01-01

    In this study, the kinetics of desorption of adsorbed hydrogen from an ideal metallic surface is modelled in Cellular Automaton (CA). The modelling is achieved by downgrading the surface to one dimension. The model consists of two parts that are surface migration and desorption. The former is attained by randomly sorting the particles at each time, the latter is realised by modelling the thermally-activated process. For the verification of this model, thermal desorption is simulated then the comparison with the chemical kinetics is carried out. Excellent agreement is observed from the result. The results show that this model is reasonable to express the recombinative desorption of two chemisorbed adatoms. Though, the application of this model is limited to the second-order reaction case. But it can be believed that the groundwork of modelling the transport dynamics of hydrogen through the surface under complex conditions is established

  7. Dynamic Simulation of 1D Cellular Automata in the Active aTAM.

    Science.gov (United States)

    Jonoska, Nataša; Karpenko, Daria; Seki, Shinnosuke

    2015-07-01

    The Active aTAM is a tile based model for self-assembly where tiles are able to transfer signals and change identities according to the signals received. We extend Active aTAM to include deactivation signals and thereby allow detachment of tiles. We show that the model allows a dynamic simulation of cellular automata with assemblies that do not record the entire computational history but only the current updates of the states, and thus provide a way for (a) algorithmic dynamical structural changes in the assembly and (b) reusable space in self-assembly. The simulation is such that at a given location the sequence of tiles that attach and detach corresponds precisely to the sequence of states the synchronous cellular automaton generates at that location.

  8. A new stochastic cellular automaton model on traffic flow and its jamming phase transition

    International Nuclear Information System (INIS)

    Sakai, Satoshi; Nishinari, Katsuhiro; Iida, Shinji

    2006-01-01

    A general stochastic traffic cellular automaton (CA) model, which includes the slow-to-start effect and driver's perspective, is proposed in this paper. It is shown that this model includes well-known traffic CA models such as the Nagel-Schreckenberg model, the quick-start model and the slow-to-start model as specific cases. Fundamental diagrams of this new model clearly show metastable states around the critical density even when the stochastic effect is present. We also obtain analytic expressions of the phase transition curve in phase diagrams by using approximate flow-density relations at boundaries. These phase transition curves are in excellent agreement with numerical results

  9. Intelligent Growth Automaton of Virtual Plant Based on Physiological Engine

    Science.gov (United States)

    Zhu, Qingsheng; Guo, Mingwei; Qu, Hongchun; Deng, Qingqing

    In this paper, a novel intelligent growth automaton of virtual plant is proposed. Initially, this intelligent growth automaton analyzes the branching pattern which is controlled by genes and then builds plant; moreover, it stores the information of plant growth, provides the interface between virtual plant and environment, and controls the growth and development of plant on the basis of environment and the function of plant organs. This intelligent growth automaton can simulate that the plant growth is controlled by genetic information system, and the information of environment and the function of plant organs. The experimental results show that the intelligent growth automaton can simulate the growth of plant conveniently and vividly.

  10. A New Cellular Automaton Method Coupled with a Rate-dependent (CARD) Model for Predicting Dynamic Recrystallization Behavior

    Science.gov (United States)

    Azarbarmas, M.; Aghaie-Khafri, M.

    2018-03-01

    A comprehensive cellular automaton (CA) model should be coupled with a rate-dependent (RD) model for analyzing the RD deformation of alloys at high temperatures. In the present study, a new CA technique coupled with an RD model—namely, CARD—was developed. The proposed CARD model was used to simulate the dynamic recrystallization phenomenon during the hot deformation of the Inconel 718 superalloy. This model is capable of calculating the mean grain size and volume fraction of dynamic recrystallized grains, and estimating the phenomenological flow behavior of the material. In the presented model, an actual orientation definition comprising three Euler angles was used by implementing the electron backscatter diffraction data. For calculating the lattice rotation of grains, it was assumed that all slip systems of grains are active during the high-temperature deformation because of the intrinsic rate dependency of the procedure. Moreover, the morphological changes in grains were obtained using a topological module.

  11. A cellular automaton method to simulate the microstructure and evolution of low-enriched uranium (LEU) U–Mo/Al dispersion type fuel plates

    Energy Technology Data Exchange (ETDEWEB)

    Drera, Saleem S., E-mail: saleem.drera@gmail.com [Mechanical Engineering, Colorado School of Mines, Golden, CO 80401 (United States); Hofman, Gerard L. [Argonne National Laboratory, Chicago, IL 60439 (United States); Kee, Robert J. [Mechanical Engineering, Colorado School of Mines, Golden, CO 80401 (United States); King, Jeffrey C. [Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO 80401 (United States)

    2014-10-15

    Highlights: • This article presents a cellular automata (CA) algorithm to synthesize the growth of intermetallic interaction layers in U–Mo/Al dispersion fuel. • The method utilizes a 3D representation of the fuel, which is discretized into separate voxels that can change identy based on derived CA rules. • The CA model is compared to ILT measurements for RERTR experimental data. • The primary objective of the model is to synthesize three-dimensional microstructures that can be used in subsequent thermal and mechanical modeling. • The CA model can be used for predictive analysis. For example, it can be used to study the dependence of temperature on interaction layer growth. - Abstract: Low-enriched uranium (LEU) fuel plates for high power materials test reactors (MTR) are composed of nominally spherical uranium–molybdenum (U–Mo) particles within an aluminum matrix. Fresh U–Mo particles typically range between 10 and 100 μm in diameter, with particle volume fractions up to 50%. As the fuel ages, reaction–diffusion processes cause the formation and growth of interaction layers that surround the fuel particles. The growth rate depends upon the temperature and radiation environment. The cellular automaton algorithm described in this paper can synthesize realistic random fuel-particle structures and simulate the growth of the intermetallic interaction layers. Examples in the present paper pack approximately 1000 particles into three-dimensional rectangular fuel structures that are approximately 1 mm on each side. The computational approach is designed to yield synthetic microstructures consistent with images from actual fuel plates and is validated by comparison with empirical data on actual fuel plates.

  12. Some Properties of topological pressure on cellular automata

    Directory of Open Access Journals (Sweden)

    Chih-Hung Chang

    2014-09-01

    Full Text Available This paper investigates the ergodicity and the power rule of the topological pressure of a cellular automaton. If a cellular automaton is either leftmost or rightmost premutive (due to the terminology given by Hedlund [Math.~Syst.~Theor.~3, 320-375, 1969], then it is ergodic with respect to the uniform Bernoulli measure. More than that, the relation of topological pressure between the original cellular automaton and its power rule is expressed in a closed form. As an application, the topological pressure of a linear cellular automaton can be computed explicitly.

  13. A Cellular Automaton / Finite Element model for predicting grain texture development in galvanized coatings

    Science.gov (United States)

    Guillemot, G.; Avettand-Fènoël, M.-N.; Iosta, A.; Foct, J.

    2011-01-01

    Hot-dipping galvanizing process is a widely used and efficient way to protect steel from corrosion. We propose to master the microstructure of zinc grains by investigating the relevant process parameters. In order to improve the texture of this coating, we model grain nucleation and growth processes and simulate the zinc solid phase development. A coupling scheme model has been applied with this aim. This model improves a previous two-dimensional model of the solidification process. It couples a cellular automaton (CA) approach and a finite element (FE) method. CA grid and FE mesh are superimposed on the same domain. The grain development is simulated at the micro-scale based on the CA grid. A nucleation law is defined using a Gaussian probability and a random set of nucleating cells. A crystallographic orientation is defined for each one with a choice of Euler's angle (Ψ,θ,φ). A small growing shape is then associated to each cell in the mushy domain and a dendrite tip kinetics is defined using the model of Kurz [2]. The six directions of basal plane and the two perpendicular directions develop in each mushy cell. During each time step, cell temperature and solid fraction are then determined at micro-scale using the enthalpy conservation relation and variations are reassigned at macro-scale. This coupling scheme model enables to simulate the three-dimensional growing kinetics of the zinc grain in a two-dimensional approach. Grain structure evolutions for various cooling times have been simulated. Final grain structure has been compared to EBSD measurements. We show that the preferentially growth of dendrite arms in the basal plane of zinc grains is correctly predicted. The described coupling scheme model could be applied for simulated other product or manufacturing processes. It constitutes an approach gathering both micro and macro scale models.

  14. Graph Cellular Automata with Relation-Based Neighbourhoods of Cells for Complex Systems Modelling: A Case of Traffic Simulation

    Directory of Open Access Journals (Sweden)

    Krzysztof Małecki

    2017-12-01

    Full Text Available A complex system is a set of mutually interacting elements for which it is possible to construct a mathematical model. This article focuses on the cellular automata theory and the graph theory in order to compare various types of cellular automata and to analyse applications of graph structures together with cellular automata. It proposes a graph cellular automaton with a variable configuration of cells and relation-based neighbourhoods (r–GCA. The developed mechanism enables modelling of phenomena found in complex systems (e.g., transport networks, urban logistics, social networks taking into account the interaction between the existing objects. As an implementation example, modelling of moving vehicles has been made and r–GCA was compared to the other cellular automata models simulating the road traffic and used in the computer simulation process.

  15. A cellular automaton simulation of contaminant transport in porous media

    International Nuclear Information System (INIS)

    Freed, D.M.; Simonson, S.A.

    1995-01-01

    A simulation tool to investigate radionuclide transport in porous groundwater flow is described. The flow systems of interest are those important in determining the fate of radionuclides emplaced in an underground repository, such as saturated matrix flow, matrix and fracture flow in the unsaturated zone, and viscous fingering in porous fractures. The work discussed here is confined to consideration of saturated flow in porous media carrying a dilute, sorptive species. The simulation technique is based on a special class of cellular automata known as lattice gas automata (LGA) which are capable of predicting hydrodynamic behavior. The original two-dimensional scheme (that of Frisch et. al. known as the FHP model) used particles of unit mass traveling on a triangular lattice with unit velocity and undergoing simple collisions which conserve mass and momentum at each node. These microscopic rules go over to the incompressible Navier-Stokes equations in the macroscopic limit. One of the strengths of this technique is the natural way that heterogeneities, such as boundaries, are accommodated. Complex geometries such as those associated with porous microstructures can be modeled effectively. Several constructions based on the FHP model have been devised, including techniques to eliminate statistical noise, extension to three dimensions, and the addition of surface tension which leads to multiphase flow

  16. Effect of psychological tension on pedestrian counter flow via an extended cost potential field cellular automaton model

    Science.gov (United States)

    Li, Xingli; Guo, Fang; Kuang, Hua; Zhou, Huaguo

    2017-12-01

    Psychology tells us that the different level of tension may lead to different behavior variation for individuals. In this paper, an extended cost potential field cellular automaton is proposed to simulate pedestrian counter flow under an emergency by considering behavior variation of pedestrian induced by psychological tension. A quantitative formula is introduced to describe behavioral changes caused by psychological tension, which also leads to the increasing cost of discomfort. The numerical simulations are performed under the periodic boundary condition and show that the presented model can capture some essential features of pedestrian counter flow, such as lane formation and segregation phenomenon for normal condition. Furthermore, an interesting feature is found that when pedestrians are in an extremely nervous state, a stable lane formation will be broken by a disordered mixture flow. The psychological nervousness under an emergency is not always negative to moving efficiency and a moderate level of tension will delay the occurrence of jamming phase. In addition, a larger asymmetrical ratio of left walkers to right walkers will improve the critical density related to the jamming phase and retard the occurrence of completely jammed phase. These findings will be helpful in pedestrian control and management under an emergency.

  17. Zeno's paradox in quantum cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    Groessing, G [Atominst. der Oesterreichischen Universitaeten, Vienna (Austria); Zeilinger, A [Inst. fuer Experimentalphysik, Univ. Innsbruck (Austria)

    1991-07-01

    The effect of Zeno's paradox in quantum theory is demonstrated with the aid of quantum mechanical cellular automata. It is shown that the degree of non-unitarity of the cellular automaton evolution and the frequency of consecutive measurements of cellular automaton states are operationally indistinguishable. (orig.).

  18. Zeno's paradox in quantum cellular automata

    International Nuclear Information System (INIS)

    Groessing, G.; Zeilinger, A.

    1991-01-01

    The effect of Zeno's paradox in quantum theory is demonstrated with the aid of quantum mechanical cellular automata. It is shown that the degree of non-unitarity of the cellular automaton evolution and the frequency of consecutive measurements of cellular automaton states are operationally indistinguishable. (orig.)

  19. Parallel 4-Dimensional Cellular Automaton Track Finder for the CBM Experiment

    International Nuclear Information System (INIS)

    Akishina, Valentina; Kisel, Ivan

    2016-01-01

    The CBM experiment (FAIR/GSI, Darmstadt, Germany) will focus on the measurement of rare probes at interaction rates up to 10 MHz with data flow of up to 1 TB/s. It requires a novel read-out and data-acquisition concept with self-triggered electronics and free-streaming data. In this case resolving different collisions is not a trivial task and event building must be performed in software online. That requires full online event reconstruction and selection not only in space, but also in time, so-called 4D event building and selection. This is a task of the First-Level Event Selection (FLES). The FLES reconstruction and selection package consists of several modules: track finding, track fitting, short-lived particles finding, event building and event selection. The Cellular Automaton (CA) track finder algorithm was adapted towards time-slice-based reconstruction and included into the CBMROOT framework. In this article, we describe the modification done to the algorithm, as well as the performance of the developed time-based approach. (paper)

  20. High Severity Wildfire Effect On Rainfall Infiltration And Runoff: A Cellular Automata Based Simulation

    Science.gov (United States)

    Vergara-Blanco, J. E.; Leboeuf-Pasquier, J.; Benavides-Solorio, J. D. D.

    2017-12-01

    A simulation software that reproduces rainfall infiltration and runoff for a storm event in a particular forest area is presented. A cellular automaton is utilized to represent space and time. On the time scale, the simulation is composed by a sequence of discrete time steps. On the space scale, the simulation is composed of forest surface cells. The software takes into consideration rain intensity and length, individual forest cell soil absorption capacity evolution, and surface angle of inclination. The software is developed with the C++ programming language. The simulation is executed on a 100 ha area within La Primavera Forest in Jalisco, Mexico. Real soil texture for unburned terrain and high severity wildfire affected terrain is employed to recreate the specific infiltration profile. Historical rainfall data of a 92 minute event is used. The Horton infiltration equation is utilized for infiltration capacity calculation. A Digital Elevation Model (DEM) is employed to reproduce the surface topography. The DEM is displayed with a 3D mesh graph where individual surface cells can be observed. The plot colouring renders water content development at the cell level throughout the storm event. The simulation shows that the cumulative infiltration and runoff which take place at the surface cell level depend on the specific storm intensity, fluctuation and length, overall terrain topography, cell slope, and soil texture. Rainfall cumulative infiltration for unburned and high severity wildfire terrain are compared: unburned terrain exhibits a significantly higher amount of rainfall infiltration.It is concluded that a cellular automaton can be utilized with a C++ program to reproduce rainfall infiltration and runoff under diverse soil texture, topographic and rainfall conditions in a forest setting. This simulation is geared for an optimization program to pinpoint the locations of a series of forest land remediation efforts to support reforestation or to minimize runoff.

  1. Cellular Automaton Study of Hydrogen Porosity Evolution Coupled with Dendrite Growth During Solidification in the Molten Pool of Al-Cu Alloys

    Science.gov (United States)

    Gu, Cheng; Wei, Yanhong; Yu, Fengyi; Liu, Xiangbo; She, Lvbo

    2017-09-01

    Welding porosity defects significantly reduce the mechanical properties of welded joints. In this paper, the hydrogen porosity evolution coupled with dendrite growth during solidification in the molten pool of Al-4.0 wt pct Cu alloy was modeled and simulated. Three phases, including a liquid phase, a solid phase, and a gas phase, were considered in this model. The growth of dendrites and hydrogen gas pores was reproduced using a cellular automaton (CA) approach. The diffusion of solute and hydrogen was calculated using the finite difference method (FDM). Columnar and equiaxed dendrite growth with porosity evolution were simulated. Competitive growth between different dendrites and porosities was observed. Dendrite morphology was influenced by porosity formation near dendrites. After solidification, when the porosities were surrounded by dendrites, they could not escape from the liquid, and they made pores that existed in the welded joints. With the increase in the cooling rate, the average diameter of porosities decreased, and the average number of porosities increased. The average diameter of porosities and the number of porosities in the simulation results had the same trend as the experimental results.

  2. Multiscale modeling of porous ceramics using movable cellular automaton method

    Science.gov (United States)

    Smolin, Alexey Yu.; Smolin, Igor Yu.; Smolina, Irina Yu.

    2017-10-01

    The paper presents a multiscale model for porous ceramics based on movable cellular automaton method, which is a particle method in novel computational mechanics of solid. The initial scale of the proposed approach corresponds to the characteristic size of the smallest pores in the ceramics. At this scale, we model uniaxial compression of several representative samples with an explicit account of pores of the same size but with the unique position in space. As a result, we get the average values of Young's modulus and strength, as well as the parameters of the Weibull distribution of these properties at the current scale level. These data allow us to describe the material behavior at the next scale level were only the larger pores are considered explicitly, while the influence of small pores is included via effective properties determined earliar. If the pore size distribution function of the material has N maxima we need to perform computations for N-1 levels in order to get the properties step by step from the lowest scale up to the macroscale. The proposed approach was applied to modeling zirconia ceramics with bimodal pore size distribution. The obtained results show correct behavior of the model sample at the macroscale.

  3. Parallel 4-dimensional cellular automaton track finder for the CBM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Akishina, Valentina [Goethe-Universitaet Frankfurt am Main, Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); JINR Joint Institute for Nuclear Research, Dubna (Russian Federation); Kisel, Ivan [Goethe-Universitaet Frankfurt am Main, Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Collaboration: CBM-Collaboration

    2016-07-01

    The CBM experiment at FAIR will focus on the measurement of rare probes at interaction rates up to 10 MHz. The beam will provide free stream of particles, so that information about different collisions may overlap in time. It requires the full online event reconstruction not only in space, but also in time, so-called 4D (4-dimensional) event building. This is a task of the First-Level Event Selection (FLES) package. The FLES reconstruction package consists of several modules: track finding, track fitting, short-lived particles finding, event building and selection. The Silicon Tracking System (STS) time measurement information was included into the Cellular Automaton (CA) track finder algorithm. The 4D track finder algorithm speed (8.5 ms per event in a time-slice) and efficiency is comparable with the event-based analysis. The CA track finder was fully parallelised inside the time-slice. The parallel version achieves a speed-up factor of 10.6 while parallelising between 10 Intel Xeon physical cores with a hyper-threading. The first version of event building based on 4D track finder was implemented.

  4. Probabilistic cellular automata.

    Science.gov (United States)

    Agapie, Alexandru; Andreica, Anca; Giuclea, Marius

    2014-09-01

    Cellular automata are binary lattices used for modeling complex dynamical systems. The automaton evolves iteratively from one configuration to another, using some local transition rule based on the number of ones in the neighborhood of each cell. With respect to the number of cells allowed to change per iteration, we speak of either synchronous or asynchronous automata. If randomness is involved to some degree in the transition rule, we speak of probabilistic automata, otherwise they are called deterministic. With either type of cellular automaton we are dealing with, the main theoretical challenge stays the same: starting from an arbitrary initial configuration, predict (with highest accuracy) the end configuration. If the automaton is deterministic, the outcome simplifies to one of two configurations, all zeros or all ones. If the automaton is probabilistic, the whole process is modeled by a finite homogeneous Markov chain, and the outcome is the corresponding stationary distribution. Based on our previous results for the asynchronous case-connecting the probability of a configuration in the stationary distribution to its number of zero-one borders-the article offers both numerical and theoretical insight into the long-term behavior of synchronous cellular automata.

  5. fA cellular automaton model of crystalline cellulose hydrolysis by cellulases

    Directory of Open Access Journals (Sweden)

    Little Bryce A

    2011-10-01

    Full Text Available Abstract Background Cellulose from plant biomass is an abundant, renewable material which could be a major feedstock for low emissions transport fuels such as cellulosic ethanol. Cellulase enzymes that break down cellulose into fermentable sugars are composed of different types - cellobiohydrolases I and II, endoglucanase and β-glucosidase - with separate functions. They form a complex interacting network between themselves, soluble hydrolysis product molecules, solution and solid phase substrates and inhibitors. There have been many models proposed for enzymatic saccharification however none have yet employed a cellular automaton approach, which allows important phenomena, such as enzyme crowding on the surface of solid substrates, denaturation and substrate inhibition, to be considered in the model. Results The Cellulase 4D model was developed de novo taking into account the size and composition of the substrate and surface-acting enzymes were ascribed behaviors based on their movements, catalytic activities and rates, affinity for, and potential for crowding of, the cellulose surface, substrates and inhibitors, and denaturation rates. A basic case modeled on literature-derived parameters obtained from Trichoderma reesei cellulases resulted in cellulose hydrolysis curves that closely matched curves obtained from published experimental data. Scenarios were tested in the model, which included variation of enzyme loadings, adsorption strengths of surface acting enzymes and reaction periods, and the effect on saccharide production over time was assessed. The model simulations indicated an optimal enzyme loading of between 0.5 and 2 of the base case concentrations where a balance was obtained between enzyme crowding on the cellulose crystal, and that the affinities of enzymes for the cellulose surface had a large effect on cellulose hydrolysis. In addition, improvements to the cellobiohydrolase I activity period substantially improved overall

  6. Marine traffic model based on cellular automaton: Considering the change of the ship's velocity under the influence of the weather and sea

    Science.gov (United States)

    Qi, Le; Zheng, Zhongyi; Gang, Longhui

    2017-10-01

    It was found that the ships' velocity change, which is impacted by the weather and sea, e.g., wind, sea wave, sea current, tide, etc., is significant and must be considered in the marine traffic model. Therefore, a new marine traffic model based on cellular automaton (CA) was proposed in this paper. The characteristics of the ship's velocity change are taken into account in the model. First, the acceleration of a ship was divided into two components: regular component and random component. Second, the mathematical functions and statistical distribution parameters of the two components were confirmed by spectral analysis, curve fitting and auto-correlation analysis methods. Third, by combining the two components, the acceleration was regenerated in the update rules for ships' movement. To test the performance of the model, the ship traffic flows in the Dover Strait, the Changshan Channel and the Qiongzhou Strait were studied and simulated. The results show that the characteristics of ships' velocities in the simulations are consistent with the measured data by Automatic Identification System (AIS). Although the characteristics of the traffic flow in different areas are different, the velocities of ships can be simulated correctly. It proves that the velocities of ships under the influence of weather and sea can be simulated successfully using the proposed model.

  7. Glider-based computing in reaction-diffusion hexagonal cellular automata

    International Nuclear Information System (INIS)

    Adamatzky, Andrew; Wuensche, Andrew; De Lacy Costello, Benjamin

    2006-01-01

    A three-state hexagonal cellular automaton, discovered in [Wuensche A. Glider dynamics in 3-value hexagonal cellular automata: the beehive rule. Int J Unconvention Comput, in press], presents a conceptual discrete model of a reaction-diffusion system with inhibitor and activator reagents. The automaton model of reaction-diffusion exhibits mobile localized patterns (gliders) in its space-time dynamics. We show how to implement the basic computational operations with these mobile localizations, and thus demonstrate collision-based logical universality of the hexagonal reaction-diffusion cellular automaton

  8. Quantum field theoretic behavior of a deterministic cellular automaton

    Energy Technology Data Exchange (ETDEWEB)

    Hooft, G ' t; Isler, K; Kalitzin, S [Inst. for Theoretical Physics, Utrecht (Netherlands)

    1992-11-16

    A certain class of cellular automata in 1 space +1 time dimension is shown to be closely related to quantum field theories containing Dirac fermions. In the massless case this relation can be studied analytically, while the introduction of Dirac mass requires numerical simulations. We show that in the last case the cellular automation describes the corresponding field theory only approximately. (orig.).

  9. Macroscopic Spatial Complexity of the Game of Life Cellular Automaton: A Simple Data Analysis

    Science.gov (United States)

    Hernández-Montoya, A. R.; Coronel-Brizio, H. F.; Rodríguez-Achach, M. E.

    In this chapter we present a simple data analysis of an ensemble of 20 time series, generated by averaging the spatial positions of the living cells for each state of the Game of Life Cellular Automaton (GoL). We show that at the macroscopic level described by these time series, complexity properties of GoL are also presented and the following emergent properties, typical of data extracted complex systems such as financial or economical come out: variations of the generated time series following an asymptotic power law distribution, large fluctuations tending to be followed by large fluctuations, and small fluctuations tending to be followed by small ones, and fast decay of linear correlations, however, the correlations associated to their absolute variations exhibit a long range memory. Finally, a Detrended Fluctuation Analysis (DFA) of the generated time series, indicates that the GoL spatial macro states described by the time series are not either completely ordered or random, in a measurable and very interesting way.

  10. Scaling, phase transitions, and nonuniversality in a self-organized critical cellular-automaton model

    International Nuclear Information System (INIS)

    Christensen, K.; Olami, Z.

    1992-01-01

    We present a two-dimensional continuous cellular automaton that is equivalent to a driven spring-block model. Both the conservation and the anisotropy in the model are controllable quantities. Above a critical level of conservation, the model exhibits self-organized criticality. The self-organization of this system and hence the critical exponents depend on the conservation and the boundary conditions. In the critical isotropic nonconservative phase, the exponents change continuously as a function of conservation. Furthermore, the exponents vary continuously when changing the boundary conditions smoothly. Consequently, there is no universality of the critical exponents. We discuss the relevance of this for earthquakes. Introducing anisotropy changes the scaling of the distribution function, but not the power-law exponent. We explore the phase diagram of this model. We find that at low conservation levels a localization transition occurs. We see two additional phase transitions. The first is seen when moving from the conservative into the nonconservative model. The second appears when passing from the anisotropic two-dimensional system to the purely one-dimensional system

  11. Stable oscillations of a predator-prey probabilistic cellular automaton: a mean-field approach

    International Nuclear Information System (INIS)

    Tome, Tania; Carvalho, Kelly C de

    2007-01-01

    We analyze a probabilistic cellular automaton describing the dynamics of coexistence of a predator-prey system. The individuals of each species are localized over the sites of a lattice and the local stochastic updating rules are inspired by the processes of the Lotka-Volterra model. Two levels of mean-field approximations are set up. The simple approximation is equivalent to an extended patch model, a simple metapopulation model with patches colonized by prey, patches colonized by predators and empty patches. This approximation is capable of describing the limited available space for species occupancy. The pair approximation is moreover able to describe two types of coexistence of prey and predators: one where population densities are constant in time and another displaying self-sustained time oscillations of the population densities. The oscillations are associated with limit cycles and arise through a Hopf bifurcation. They are stable against changes in the initial conditions and, in this sense, they differ from the Lotka-Volterra cycles which depend on initial conditions. In this respect, the present model is biologically more realistic than the Lotka-Volterra model

  12. Recursive definition of global cellular-automata mappings

    DEFF Research Database (Denmark)

    Feldberg, Rasmus; Knudsen, Carsten; Rasmussen, Steen

    1994-01-01

    A method for a recursive definition of global cellular-automata mappings is presented. The method is based on a graphical representation of global cellular-automata mappings. For a given cellular-automaton rule the recursive algorithm defines the change of the global cellular-automaton mapping...... as the number of lattice sites is incremented. A proof of lattice size invariance of global cellular-automata mappings is derived from an approximation to the exact recursive definition. The recursive definitions are applied to calculate the fractal dimension of the set of reachable states and of the set...

  13. An Asynchronous Recurrent Network of Cellular Automaton-Based Neurons and Its Reproduction of Spiking Neural Network Activities.

    Science.gov (United States)

    Matsubara, Takashi; Torikai, Hiroyuki

    2016-04-01

    Modeling and implementation approaches for the reproduction of input-output relationships in biological nervous tissues contribute to the development of engineering and clinical applications. However, because of high nonlinearity, the traditional modeling and implementation approaches encounter difficulties in terms of generalization ability (i.e., performance when reproducing an unknown data set) and computational resources (i.e., computation time and circuit elements). To overcome these difficulties, asynchronous cellular automaton-based neuron (ACAN) models, which are described as special kinds of cellular automata that can be implemented as small asynchronous sequential logic circuits have been proposed. This paper presents a novel type of such ACAN and a theoretical analysis of its excitability. This paper also presents a novel network of such neurons, which can mimic input-output relationships of biological and nonlinear ordinary differential equation model neural networks. Numerical analyses confirm that the presented network has a higher generalization ability than other major modeling and implementation approaches. In addition, Field-Programmable Gate Array-implementations confirm that the presented network requires lower computational resources.

  14. Recursive definition of global cellular-automata mappings

    International Nuclear Information System (INIS)

    Feldberg, R.; Knudsen, C.; Rasmussen, S.

    1994-01-01

    A method for a recursive definition of global cellular-automata mappings is presented. The method is based on a graphical representation of global cellular-automata mappings. For a given cellular-automaton rule the recursive algorithm defines the change of the global cellular-automaton mapping as the number of lattice sites is incremented. A proof of lattice size invariance of global cellular-automata mappings is derived from an approximation to the exact recursive definition. The recursive definitions are applied to calculate the fractal dimension of the set of reachable states and of the set of fixed points of cellular automata on an infinite lattice

  15. Cellular automaton for migration in ecosystem: Application of traffic model to a predator-prey system

    Science.gov (United States)

    Nagatani, Takashi; Tainaka, Kei-ichi

    2018-01-01

    In most cases, physicists have studied the migration of biospecies by the use of random walk. In the present article, we apply cellular automaton of traffic model. For simplicity, we deal with an ecosystem contains a prey and predator, and use one-dimensional lattice with two layers. Preys stay on the first layer, but predators uni-directionally move on the second layer. The spatial and temporal evolution is numerically explored. It is shown that the migration has the important effect on populations of both prey and predator. Without migration, the phase transition between a prey-phase and coexisting-phase occurs. In contrast, the phase transition disappears by migration. This is because predator can survive due to migration. We find another phase transition for spatial distribution: in one phase, prey and predator form a stripe pattern of condensation and rarefaction, while in the other phase, they uniformly distribute. The self-organized stripe may be similar to the migration patterns in real ecosystems.

  16. TWO-DIMENSIONAL CELLULAR AUTOMATON MODEL FOR THE EVOLUTION OF ACTIVE REGION CORONAL PLASMAS

    Energy Technology Data Exchange (ETDEWEB)

    López Fuentes, Marcelo [Instituto de Astronomía y Física del Espacio, CONICET-UBA, CC. 67, Suc. 28, 1428 Buenos Aires (Argentina); Klimchuk, James A., E-mail: lopezf@iafe.uba.ar [NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States)

    2015-02-01

    We study a two-dimensional cellular automaton (CA) model for the evolution of coronal loop plasmas. The model is based on the idea that coronal loops are made of elementary magnetic strands that are tangled and stressed by the displacement of their footpoints by photospheric motions. The magnetic stress accumulated between neighbor strands is released in sudden reconnection events or nanoflares that heat the plasma. We combine the CA model with the Enthalpy Based Thermal Evolution of Loops model to compute the response of the plasma to the heating events. Using the known response of the X-Ray Telescope on board Hinode, we also obtain synthetic data. The model obeys easy-to-understand scaling laws relating the output (nanoflare energy, temperature, density, intensity) to the input parameters (field strength, strand length, critical misalignment angle). The nanoflares have a power-law distribution with a universal slope of –2.5, independent of the input parameters. The repetition frequency of nanoflares, expressed in terms of the plasma cooling time, increases with strand length. We discuss the implications of our results for the problem of heating and evolution of active region coronal plasmas.

  17. A NANOFLARE-BASED CELLULAR AUTOMATON MODEL AND THE OBSERVED PROPERTIES OF THE CORONAL PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, Marcelo López [Instituto de Astronomía y Física del Espacio, CONICET-UBA, CC. 67, Suc. 28, 1428 Buenos Aires (Argentina); Klimchuk, James A., E-mail: lopezf@iafe.uba.ar [NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States)

    2016-09-10

    We use the cellular automaton model described in López Fuentes and Klimchuk to study the evolution of coronal loop plasmas. The model, based on the idea of a critical misalignment angle in tangled magnetic fields, produces nanoflares of varying frequency with respect to the plasma cooling time. We compare the results of the model with active region (AR) observations obtained with the Hinode /XRT and SDO /AIA instruments. The comparison is based on the statistical properties of synthetic and observed loop light curves. Our results show that the model reproduces the main observational characteristics of the evolution of the plasma in AR coronal loops. The typical intensity fluctuations have amplitudes of 10%–15% both for the model and the observations. The sign of the skewness of the intensity distributions indicates the presence of cooling plasma in the loops. We also study the emission measure (EM) distribution predicted by the model and obtain slopes in log(EM) versus log(T) between 2.7 and 4.3, in agreement with published observational values.

  18. A Nanoflare-Based Cellular Automaton Model and the Observed Properties of the Coronal Plasma

    Science.gov (United States)

    Lopez-Fuentes, Marcelo; Klimchuk, James Andrew

    2016-01-01

    We use the cellular automaton model described in Lopez Fuentes and Klimchuk to study the evolution of coronal loop plasmas. The model, based on the idea of a critical misalignment angle in tangled magnetic fields, produces nanoflares of varying frequency with respect to the plasma cooling time. We compare the results of the model with active region (AR) observations obtained with the Hinode/XRT and SDOAIA instruments. The comparison is based on the statistical properties of synthetic and observed loop light curves. Our results show that the model reproduces the main observational characteristics of the evolution of the plasma in AR coronal loops. The typical intensity fluctuations have amplitudes of 10 percent - 15 percent both for the model and the observations. The sign of the skewness of the intensity distributions indicates the presence of cooling plasma in the loops. We also study the emission measure (EM) distribution predicted by the model and obtain slopes in log(EM) versus log(T) between 2.7 and 4.3, in agreement with published observational values.

  19. An intrinsic poperty of memory of the Cellular automaton infrastructure of Nature leading to the organization of the physical world as an Internet o things; TOE = IOT

    Science.gov (United States)

    Berkovich, Simon

    2015-04-01

    The undamental advantage of a Cellular automaton construction foris that it can be viewed as an undetectable absolute frame o reference, in accordance with Lorentz-Poincare's interpretation.. The cellular automaton model for physical poblems comes upon two basic hurdles: (1) How to find the Elemental Rule that, and how to get non-locality from local transformations. Both problems are resolved considering the transfomation rule of mutual distributed synchronization Actually any information proessing device starts with a clocking system. and it turns out that ``All physical phenomena are different aspects of the high-level description of distributed mutual synchronization in a network of digital clocks''. Non-locality comes from two hugely different time-scales of signaling.. The universe is acombinines information and matter processes, These fast spreading diffusion wave solutions create the mechanism of the Holographic Universe. And thirdly Disengaged from synchronization, circular counters can perform memory functions by retaining phases of their oscillations, an idea of Von Neumann'. Thus, the suggested model generates the necessary constructs for the physical world as an Internet of Things. Life emerges due to the specifics of macromolecules that serve as communication means, with the holographic memory...

  20. Wavefront cellular learning automata.

    Science.gov (United States)

    Moradabadi, Behnaz; Meybodi, Mohammad Reza

    2018-02-01

    This paper proposes a new cellular learning automaton, called a wavefront cellular learning automaton (WCLA). The proposed WCLA has a set of learning automata mapped to a connected structure and uses this structure to propagate the state changes of the learning automata over the structure using waves. In the WCLA, after one learning automaton chooses its action, if this chosen action is different from the previous action, it can send a wave to its neighbors and activate them. Each neighbor receiving the wave is activated and must choose a new action. This structure for the WCLA is necessary in many dynamic areas such as social networks, computer networks, grid computing, and web mining. In this paper, we introduce the WCLA framework as an optimization tool with diffusion capability, study its behavior over time using ordinary differential equation solutions, and present its accuracy using expediency analysis. To show the superiority of the proposed WCLA, we compare the proposed method with some other types of cellular learning automata using two benchmark problems.

  1. Wavefront cellular learning automata

    Science.gov (United States)

    Moradabadi, Behnaz; Meybodi, Mohammad Reza

    2018-02-01

    This paper proposes a new cellular learning automaton, called a wavefront cellular learning automaton (WCLA). The proposed WCLA has a set of learning automata mapped to a connected structure and uses this structure to propagate the state changes of the learning automata over the structure using waves. In the WCLA, after one learning automaton chooses its action, if this chosen action is different from the previous action, it can send a wave to its neighbors and activate them. Each neighbor receiving the wave is activated and must choose a new action. This structure for the WCLA is necessary in many dynamic areas such as social networks, computer networks, grid computing, and web mining. In this paper, we introduce the WCLA framework as an optimization tool with diffusion capability, study its behavior over time using ordinary differential equation solutions, and present its accuracy using expediency analysis. To show the superiority of the proposed WCLA, we compare the proposed method with some other types of cellular learning automata using two benchmark problems.

  2. Modeling and simulation of a controlled steam generator in the context of dynamic reliability using a Stochastic Hybrid Automaton

    International Nuclear Information System (INIS)

    Babykina, Génia; Brînzei, Nicolae; Aubry, Jean-François; Deleuze, Gilles

    2016-01-01

    The paper proposes a modeling framework to support Monte Carlo simulations of the behavior of a complex industrial system. The aim is to analyze the system dependability in the presence of random events, described by any type of probability distributions. Continuous dynamic evolutions of physical parameters are taken into account by a system of differential equations. Dynamic reliability is chosen as theoretical framework. Based on finite state automata theory, the formal model is built by parallel composition of elementary sub-models using a bottom-up approach. Considerations of a stochastic nature lead to a model called the Stochastic Hybrid Automaton. The Scilab/Scicos open source environment is used for implementation. The case study is carried out on an example of a steam generator of a nuclear power plant. The behavior of the system is studied by exploring its trajectories. Possible system trajectories are analyzed both empirically, using the results of Monte Carlo simulations, and analytically, using the formal system model. The obtained results are show to be relevant. The Stochastic Hybrid Automaton appears to be a suitable tool to address the dynamic reliability problem and to model real systems of high complexity; the bottom-up design provides precision and coherency of the system model. - Highlights: • A part of a nuclear power plant is modeled in the context of dynamic reliability. • Stochastic Hybrid Automaton is used as an input model for Monte Carlo simulations. • The model is formally built using a bottom-up approach. • The behavior of the system is analyzed empirically and analytically. • A formally built SHA shows to be a suitable tool to approach dynamic reliability.

  3. Three-dimensional cellular automaton-finite element modeling of solidification grain structures for arc-welding processes

    International Nuclear Information System (INIS)

    Chen, Shijia; Guillemot, Gildas; Gandin, Charles-André

    2016-01-01

    Solidification grain structure has significant impact on the final properties of welded parts using fusion welding processes. Direct simulation of grain structure at industrial scale is yet rarely reported in the literature and remains a challenge. A three-dimensional (3D) coupled Cellular Automaton (CA) – Finite Element (FE) model is presented that predicts the grain structure formation during multiple passes Gas Tungsten Arc Welding (GTAW) and Gas Metal Arc Welding (GMAW). The FE model is established in a level set (LS) approach that tracks the evolution of the metal-shielding gas interface due to the addition of metal. The FE method solves the mass, energy and momentum conservation equations for the metal plus shielding gas system based on an adaptive mesh (FE mesh). Fields are projected in a second FE mesh, named CA mesh. A CA grid made of a regular lattice of cubic cells is created to overlay the fixed CA mesh. The CA model based on the CA grid simulates the melting and growth of the grain boundaries in the liquid pool. In order to handle large computational domains while keeping reasonable computational costs, parallel computations and dynamic strategies for the allocation/deallocation of the CA grid are introduced. These strategies correspond to significant optimizations of the computer memories that are demonstrated. The 3D CAFE model is first applied to the simple configuration of single linear passes by GTAW of a duplex stainless steel URANUS 2202. It is then applied to a more persuasive example considering GMAW in spray transfer mode during multiple passes to fill a V-groove chamfer. Simulations reveal the possibility to handle domains with millions of grains in representative domain sizes while following the formation of textures that result from the growth competition among columnar grains. -- Graphical abstract: Simulated 3D grain structure (3D CAFE model) for GTAW multiple linear passes at the surface of a duplex stainless steel (URANUS 22002

  4. Towards modeling of random lasing in dye doped bio-organic based systems: ray-tracing and cellular automaton analysis

    Science.gov (United States)

    Mitus, A. C.; Stopa, P.; Zaklukiewicz, W.; Pawlik, G.; Mysliwiec, J.; Kajzar, F.; Rau, I.

    2015-08-01

    One of many photonic applications of biopolymers as functional materials is random lasing resulting from an incorporation of highly luminescent dyes into biopolymeric matrix, which leads to a random but coherent light scattering in amplifying medium. In spite of numerous theoretical and experimental studies the origin of the coherence is still not clear and various scenarios are discussed. In particular, inhomogeneity of biopolymeric layers can hypothetically promote the feedback in the scattering of the emitted light resulting in coherent and incoherent random lasing. In this paper we analyze the light scattering in a model system of scattering centers of circular shapes and various dimensions using ray-tracing techniques. In the second part, which has mostly a tutorial character, we present the approach to the study of random lasing using a cellular automaton model of Wiersma et al.

  5. Statistical mechanics of cellular automata

    International Nuclear Information System (INIS)

    Wolfram, S.

    1983-01-01

    Cellular automata are used as simple mathematical models to investigate self-organization in statistical mechanics. A detailed analysis is given of ''elementary'' cellular automata consisting of a sequence of sites with values 0 or 1 on a line, with each site evolving deterministically in discrete time steps according to p definite rules involving the values of its nearest neighbors. With simple initial configurations, the cellular automata either tend to homogeneous states, or generate self-similar patterns with fractal dimensions approx. =1.59 or approx. =1.69. With ''random'' initial configurations, the irreversible character of the cellular automaton evolution leads to several self-organization phenomena. Statistical properties of the structures generated are found to lie in two universality classes, independent of the details of the initial state or the cellular automaton rules. More complicated cellular automata are briefly considered, and connections with dynamical systems theory and the formal theory of computation are discussed

  6. Simulating Flaring Events via an Intelligent Cellular Automata Mechanism

    Science.gov (United States)

    Dimitropoulou, M.; Vlahos, L.; Isliker, H.; Georgoulis, M.

    2010-07-01

    We simulate flaring events through a Cellular Automaton (CA) model, in which, for the first time, we use observed vector magnetograms as initial conditions. After non-linear force free extrapolation of the magnetic field from the vector magnetograms, we identify magnetic discontinuities, using two alternative criteria: (1) the average magnetic field gradient, or (2) the normalized magnetic field curl (i.e. the current). Magnetic discontinuities are identified at the grid-sites where the magnetic field gradient or curl exceeds a specified threshold. We then relax the magnetic discontinuities according to the rules of Lu and Hamilton (1991) or Lu et al. (1993), i.e. we redistribute the magnetic field locally so that the discontinuities disappear. In order to simulate the flaring events, we consider several alternative scenarios with regard to: (1) The threshold above which magnetic discontinuities are identified (applying low, high, and height-dependent threshold values); (2) The driving process that occasionally causes new discontinuities (at randomly chosen grid sites, magnetic field increments are added that are perpendicular (or may-be also parallel) to the existing magnetic field). We address the question whether the coronal active region magnetic fields can indeed be considered to be in the state of self-organized criticality (SOC).

  7. Reversible one-dimensional cellular automata with one of the two Welch indices equal to 1 and full shifts

    International Nuclear Information System (INIS)

    Mora, Juan Carlos Seck Tuoh; Hernandez, Manuel Gonzalez; Vergara, Sergio V Chapa

    2003-01-01

    Reversible cellular automata are invertible discrete dynamical systems which have been widely studied both for analysing interesting theoretical questions and for obtaining relevant practical applications, for instance, simulating invertible natural systems or implementing data coding devices. An important problem in the theory of reversible automata is to know how the local behaviour which is not invertible is able to yield a reversible global one. In this sense, symbolic dynamics plays an important role for obtaining an adequate representation of a reversible cellular automaton. In this paper we prove the equivalence between a reversible automaton where the ancestors only differ at one side (technically with one of the two Welch indices equal to 1) and a full shift. We represent any reversible automaton by a de Bruijn diagram, and we characterize the way in which the diagram produces an evolution formed by undefined repetitions of two states. By means of amalgamations, we prove that there is always a way of transforming a de Bruijn diagram into the full shift. Finally, we provide an example illustrating the previous results

  8. Reversible one-dimensional cellular automata with one of the two Welch indices equal to 1 and full shifts

    Energy Technology Data Exchange (ETDEWEB)

    Mora, Juan Carlos Seck Tuoh [Centro de Investigacion Avanzada en Ingenieria Industrial, Universidad Autonoma del Estado de Hidalgo, Carr Pachuca-Tulancingo Km 4.5, 42020 Pachuca (Mexico); Hernandez, Manuel Gonzalez [Centro de Investigacion Avanzada en Ingenieria Industrial, Universidad Autonoma del Estado de Hidalgo, Carr Pachuca-Tulancingo Km 4.5, 42020 Pachuca (Mexico); Vergara, Sergio V Chapa [Depto de Ingenieria Electrica, Seccion Computacion, Centro de Investigacion y de Estudios Avanzados, Instituto Politecnico Nacional, Av IPN 2508, Col San Pedro Zacatenco, 07300 DF (Mexico)

    2003-07-25

    Reversible cellular automata are invertible discrete dynamical systems which have been widely studied both for analysing interesting theoretical questions and for obtaining relevant practical applications, for instance, simulating invertible natural systems or implementing data coding devices. An important problem in the theory of reversible automata is to know how the local behaviour which is not invertible is able to yield a reversible global one. In this sense, symbolic dynamics plays an important role for obtaining an adequate representation of a reversible cellular automaton. In this paper we prove the equivalence between a reversible automaton where the ancestors only differ at one side (technically with one of the two Welch indices equal to 1) and a full shift. We represent any reversible automaton by a de Bruijn diagram, and we characterize the way in which the diagram produces an evolution formed by undefined repetitions of two states. By means of amalgamations, we prove that there is always a way of transforming a de Bruijn diagram into the full shift. Finally, we provide an example illustrating the previous results.

  9. Calibrating cellular automaton models for pedestrians walking through corners

    Science.gov (United States)

    Dias, Charitha; Lovreglio, Ruggiero

    2018-05-01

    Cellular Automata (CA) based pedestrian simulation models have gained remarkable popularity as they are simpler and easier to implement compared to other microscopic modeling approaches. However, incorporating traditional floor field representations in CA models to simulate pedestrian corner navigation behavior could result in unrealistic behaviors. Even though several previous studies have attempted to enhance CA models to realistically simulate pedestrian maneuvers around bends, such modifications have not been calibrated or validated against empirical data. In this study, two static floor field (SFF) representations, namely 'discrete representation' and 'continuous representation', are calibrated for CA-models to represent pedestrians' walking behavior around 90° bends. Trajectory data collected through a controlled experiment are used to calibrate these model representations. Calibration results indicate that although both floor field representations can represent pedestrians' corner navigation behavior, the 'continuous' representation fits the data better. Output of this study could be beneficial for enhancing the reliability of existing CA-based models by representing pedestrians' corner navigation behaviors more realistically.

  10. Predictability in cellular automata.

    Science.gov (United States)

    Agapie, Alexandru; Andreica, Anca; Chira, Camelia; Giuclea, Marius

    2014-01-01

    Modelled as finite homogeneous Markov chains, probabilistic cellular automata with local transition probabilities in (0, 1) always posses a stationary distribution. This result alone is not very helpful when it comes to predicting the final configuration; one needs also a formula connecting the probabilities in the stationary distribution to some intrinsic feature of the lattice configuration. Previous results on the asynchronous cellular automata have showed that such feature really exists. It is the number of zero-one borders within the automaton's binary configuration. An exponential formula in the number of zero-one borders has been proved for the 1-D, 2-D and 3-D asynchronous automata with neighborhood three, five and seven, respectively. We perform computer experiments on a synchronous cellular automaton to check whether the empirical distribution obeys also that theoretical formula. The numerical results indicate a perfect fit for neighbourhood three and five, which opens the way for a rigorous proof of the formula in this new, synchronous case.

  11. Intractable problems in reversible cellular automata

    International Nuclear Information System (INIS)

    Vatan, F.

    1988-01-01

    The billiard ball model, a classical mechanical system in which all parameters are real variables, can perform all digital computations. An eight-state, 11-neighbor reversible cellular automaton (an entirely discrete system in which all parameters are integer variables) can simulate this model. One of the natural problems for this system is to determine the shape of a container so that they initial specific distribution of gas molecules eventually leads to a predetermined distribution. This problem if PSPACE-complete. Related intractable and decidable problems are discussed as well

  12. Multi Car Elevator Control by using Learning Automaton

    Science.gov (United States)

    Shiraishi, Kazuaki; Hamagami, Tomoki; Hirata, Hironori

    We study an adaptive control technique for multi car elevators (MCEs) by adopting learning automatons (LAs.) The MCE is a high performance and a near-future elevator system with multi shafts and multi cars. A strong point of the system is that realizing a large carrying capacity in small shaft area. However, since the operation is too complicated, realizing an efficient MCE control is difficult for top-down approaches. For example, “bunching up together" is one of the typical phenomenon in a simple traffic environment like the MCE. Furthermore, an adapting to varying environment in configuration requirement is a serious issue in a real elevator service. In order to resolve these issues, having an autonomous behavior is required to the control system of each car in MCE system, so that the learning automaton, as the solutions for this requirement, is supposed to be appropriate for the simple traffic control. First, we assign a stochastic automaton (SA) to each car control system. Then, each SA varies its stochastic behavior distributions for adapting to environment in which its policy is evaluated with each passenger waiting times. That is LA which learns the environment autonomously. Using the LA based control technique, the MCE operation efficiency is evaluated through simulation experiments. Results show the technique enables reducing waiting times efficiently, and we confirm the system can adapt to the dynamic environment.

  13. An Urban Cellular Automata Model for Simulating Dynamic States on a Local Scale

    Directory of Open Access Journals (Sweden)

    Jenni Partanen

    2016-12-01

    Full Text Available In complex systems, flexibility and adaptability to changes are crucial to the systems’ dynamic stability and evolution. Such resilience requires that the system is able to respond to disturbances by self-organizing, which implies a certain level of entropy within the system. Dynamic states (static, cyclical/periodic, complex, and chaotic reflect this generative capacity, and correlate with the level of entropy. For planning complex cities, we need to develop methods to guide such autonomous progress in an optimal manner. A classical apparatus, cellular automaton (CA, provides such a tool. Applications of CA help us to study temporal dynamics in self-organizing urban systems. By exploring the dynamic states of the model’s dynamics resulting from different border conditions it is possible to discover favorable set(s of rules conductive to the self-organizing dynamics and enable the system’s recovery at the time of crises. Level of entropy is a relevant measurement for evaluation of these dynamic states. The 2-D urban cellular automaton model studied here is based on the microeconomic principle that similar urban activities are attracted to each other, especially in certain self-organizing areas, and that the local dynamics of these enclaves affect the dynamics of the urban region by channeling flows of information, goods and people. The results of the modeling experiment indicate that the border conditions have a major impact on the model’s dynamics generating various dynamic states of the system. Most importantly, it seemed that the model could simulate a favorable, complex dynamic state with medium entropy level which may refer to the continuous self-organization of the system. The model provides a tool for exploring and understanding the effects of boundary conditions in the planning process as various scenarios are tested: resulting dynamics of the system can be explored with such “planning rules” prior to decisions, helping to

  14. An improved cellular automata model for train operation simulation with dynamic acceleration

    Science.gov (United States)

    Li, Wen-Jun; Nie, Lei

    2018-03-01

    Urban rail transit plays an important role in the urban public traffic because of its advantages of fast speed, large transport capacity, high safety, reliability and low pollution. This study proposes an improved cellular automaton (CA) model by considering the dynamic characteristic of the train acceleration to analyze the energy consumption and train running time. Constructing an effective model for calculating energy consumption to aid train operation improvement is the basis for studying and analyzing energy-saving measures for urban rail transit system operation.

  15. Cellular automaton for surface reactions

    Energy Technology Data Exchange (ETDEWEB)

    Pechatnikov, E L [AN SSSR, Chernogolovka (Russian Federation). Otdelenie Inst. Khimicheskoj Fiziki; Frankowicz, A; Danielak, R [Uniwersytet Jagiellonski, Cracow (Poland)

    1994-06-01

    A new algorithm which overcomes some specific difficulties arising in modeling of heterogeneous catalytic processes by cellular automata (CA) technique is proposed. The algorithm was tested with scheme introduced by Ziff, Gulari and Barshad and showed a good agreement with their results. The problem of the physical adequacy and interpretation of the algorithm was discussed. (author). 10 refs, 4 figs.

  16. Effect of Temperature and Fluid Flow on Dendrite Growth During Solidification of Al-3 Wt Pct Cu Alloy by the Two-Dimensional Cellular Automaton Method

    Science.gov (United States)

    Gu, Cheng; Wei, Yanhong; Liu, Renpei; Yu, Fengyi

    2017-12-01

    A two-dimensional cellular automaton-finite volume model was developed to simulate dendrite growth of Al-3 wt pct Cu alloy during solidification to investigate the effect of temperature and fluid flow on dendrite morphology, solute concentration distribution, and dendrite growth velocity. Different calculation conditions that may influence the results of the simulation, including temperature and flow, were considered. The model was also employed to study the effect of different undercoolings, applied temperature fields, and forced flow velocities on solute segregation and dendrite growth. The initial temperature and fluid flow have a significant impact on the dendrite morphologies and solute profiles during solidification. The release of energy is operated with solidification and results in the increase of temperature. A larger undercooling leads to larger solute concentration near the solid/liquid interface and solute concentration gradient at the same time-step. Solute concentration in the solid region tends to increase with the increase of undercooling. Four vortexes appear under the condition when natural flow exists: the two on the right of the dendrite rotate clockwise, and those on the left of the dendrite rotate counterclockwise. With the increase of forced flow velocity, the rejected solute in the upstream region becomes easier to be washed away and enriched in the downstream region, resulting in acceleration of the growth of the dendrite in the upstream and inhibiting the downstream dendrite growth. The dendrite perpendicular to fluid flow shows a coarser morphology in the upstream region than that of the downstream. Almost no secondary dendrite appears during the calculation process.

  17. Simulating the impacts of on-street vehicle parking on traffic operations on urban streets using cellular automation

    Science.gov (United States)

    Chen, Jingxu; Li, Zhibin; Jiang, Hang; Zhu, Senlai; Wang, Wei

    2017-02-01

    In recent years, many bicycle lanes on urban streets are replaced with vehicle parking places. Spaces for bicycle riding are reduced, resulting in changes in bicycle and vehicle operational features. The objective of this study is to estimate the impacts of on-street parking on heterogeneous traffic operation on urban streets. A cellular automaton (CA) model is developed and calibrated to simulate bicycle lane-changing on streets with on-street parking. Two types of street segments with different bicycle lane width are considered. From the simulation, two types of conflicts between bicycles and vehicles are identified which are frictional conflicts and blocking conflicts. Factors affecting the frequency of conflicts are also identified. Based on the results, vehicle delay is estimated for various traffic situations considering the range of occupancy levels for on-street parking. Later, a numerical network example is analyzed to estimate the network impact of on-street parking on traffic assignment and operation. Findings of the study are helpful to policies and design regarding on-street vehicle parking to improve the efficiency of traffic operations.

  18. Genetic Algorithm Calibration of Probabilistic Cellular Automata for Modeling Mining Permit Activity

    Science.gov (United States)

    Louis, S.J.; Raines, G.L.

    2003-01-01

    We use a genetic algorithm to calibrate a spatially and temporally resolved cellular automata to model mining activity on public land in Idaho and western Montana. The genetic algorithm searches through a space of transition rule parameters of a two dimensional cellular automata model to find rule parameters that fit observed mining activity data. Previous work by one of the authors in calibrating the cellular automaton took weeks - the genetic algorithm takes a day and produces rules leading to about the same (or better) fit to observed data. These preliminary results indicate that genetic algorithms are a viable tool in calibrating cellular automata for this application. Experience gained during the calibration of this cellular automata suggests that mineral resource information is a critical factor in the quality of the results. With automated calibration, further refinements of how the mineral-resource information is provided to the cellular automaton will probably improve our model.

  19. A Universal Semi-totalistic Cellular Automaton on Kite and Dart Penrose Tilings

    Directory of Open Access Journals (Sweden)

    Katsunobu Imai

    2012-08-01

    Full Text Available In this paper we investigate certain properties of semi-totalistic cellular automata (CA on the well known quasi-periodic kite and dart two dimensional tiling of the plane presented by Roger Penrose. We show that, despite the irregularity of the underlying grid, it is possible to devise a semi-totalistic CA capable of simulating any boolean circuit on this aperiodic tiling.

  20. Cellular Automata and the Humanities.

    Science.gov (United States)

    Gallo, Ernest

    1994-01-01

    The use of cellular automata to analyze several pre-Socratic hypotheses about the evolution of the physical world is discussed. These hypotheses combine characteristics of both rigorous and metaphoric language. Since the computer demands explicit instructions for each step in the evolution of the automaton, such models can reveal conceptual…

  1. FPGA Implementation of one-dimensional and two-dimensional cellular automata

    International Nuclear Information System (INIS)

    D'Antone, I.

    1999-01-01

    This report describes the hardware implementation of one-dimensional and two-dimensional cellular automata (CAs). After a general introduction to the cellular automata, we consider a one-dimensional CA used to implement pseudo-random techniques in built-in self test for VLSI. Due to the increase in digital ASIC complexity, testing is becoming one of the major costs in the VLSI production. The high electronics complexity, used in particle physics experiments, demands higher reliability than in the past time. General criterions are given to evaluate the feasibility of the circuit used for testing and some quantitative parameters are underlined to optimize the architecture of the cellular automaton. Furthermore, we propose a two-dimensional CA that performs a peak finding algorithm in a matrix of cells mapping a sub-region of a calorimeter. As in a two-dimensional filtering process, the peaks of the energy clusters are found in one evolution step. This CA belongs to Wolfram class II cellular automata. Some quantitative parameters are given to optimize the architecture of the cellular automaton implemented in a commercial field programmable gate array (FPGA)

  2. Mesoscopic simulation of recrystallization and grain growth

    International Nuclear Information System (INIS)

    Rollett, A.D.

    2000-01-01

    A brief summary of simulation techniques for recrystallization and grain growth is given. The available methods include surface evolver, front tracking (including finite element methods and vertex methods), networks of curves, phase field, cellular automata, and Monte Carlo. Two of the models that use a regular lattice, the Potts model and the Cellular Automaton (CA) model, have proved to be very useful. Microstructure is represented on a discrete lattice where the value of the field at each point represents the local orientation of the material and boundaries exist between points of unlike orientation. Two issues are discussed: one is a hybrid approach to combining the standard Monte Carlo and cellular automata algorithms for recrystallization modeling. The second is adaptation of the MC method for modeling grain growth (and recrystallization) with physically based boundary properties. Both models have significant limitations in their standard forms. The CA model is very useful and efficient for simulating recrystallization with deterministic motion of the recrystallization fronts. It can be adapted to simulate curvature driven migration provided that multiple sub-lattices are used with a probabilistic switching rule. The Potts model is very successful in modeling curvature driven boundary migration and grain growth. It does not simulate the proportionality between boundary velocity and a stored energy driving force, however, unless rather restricted conditions of stored energy (in relation to the grain boundary energy) and lattice temperature are satisfied. A new approach based on a hybrid of the Potts model (MC) and the Cellular Automaton (CA) model has been developed to obtain the desired limiting behavior for both curvature-driven and stored energy-driven grain boundary migration. The combination of methods is achieved by interleaving the two different types of reorientation event in time. The results show that the hybrid algorithm models the Gibbs

  3. Car Deceleration Considering Its Own Velocity in Cellular Automata Model

    International Nuclear Information System (INIS)

    Li Keping

    2006-01-01

    In this paper, we propose a new cellular automaton model, which is based on NaSch traffic model. In our method, when a car has a larger velocity, if the gap between the car and its leading car is not enough large, it will decrease. The aim is that the following car has a buffer space to decrease its velocity at the next time, and then avoid to decelerate too high. The simulation results show that using our model, the car deceleration is realistic, and is closer to the field measure than that of NaSch model.

  4. Phase transitions enable computational universality in neuristor-based cellular automata

    International Nuclear Information System (INIS)

    Pickett, Matthew D; Stanley Williams, R

    2013-01-01

    We recently demonstrated that Mott memristors, two-terminal devices that exhibit threshold switching via an insulator to conductor phase transition, can serve as the active components necessary to build a neuristor, a biomimetic threshold spiking device. Here we extend those results to demonstrate, in simulation, neuristor-based circuits capable of performing general Boolean logic operations. We additionally show that these components can be used to construct a one-dimensional cellular automaton, rule 137, previously proven to be universal. This proof-of-principle shows that localized phase transitions can perform spiking computation, which is of particular interest for neuromorphic hardware. (paper)

  5. Overview of cellular automaton models for corrosion

    International Nuclear Information System (INIS)

    Perez-Brokate, Cristian Felipe; De Lamare, Jacques; Dung di Caprio; Feron, Damien; Chausse, Annie

    2014-01-01

    A review of corrosion process modeling using cellular automata methods is presented. This relatively new and growing approach takes into account the stochastic nature of the phenomena and uses physico-chemical rules to make predictions at a mesoscopic scale. Milestone models are analyzed and perspectives are established. (authors)

  6. FACC: A Novel Finite Automaton Based on Cloud Computing for the Multiple Longest Common Subsequences Search

    Directory of Open Access Journals (Sweden)

    Yanni Li

    2012-01-01

    Full Text Available Searching for the multiple longest common subsequences (MLCS has significant applications in the areas of bioinformatics, information processing, and data mining, and so forth, Although a few parallel MLCS algorithms have been proposed, the efficiency and effectiveness of the algorithms are not satisfactory with the increasing complexity and size of biologic data. To overcome the shortcomings of the existing MLCS algorithms, and considering that MapReduce parallel framework of cloud computing being a promising technology for cost-effective high performance parallel computing, a novel finite automaton (FA based on cloud computing called FACC is proposed under MapReduce parallel framework, so as to exploit a more efficient and effective general parallel MLCS algorithm. FACC adopts the ideas of matched pairs and finite automaton by preprocessing sequences, constructing successor tables, and common subsequences finite automaton to search for MLCS. Simulation experiments on a set of benchmarks from both real DNA and amino acid sequences have been conducted and the results show that the proposed FACC algorithm outperforms the current leading parallel MLCS algorithm FAST-MLCS.

  7. A quantum Samaritan’s dilemma cellular automaton

    Science.gov (United States)

    Situ, Haozhen

    2017-01-01

    The dynamics of a spatial quantum formulation of the iterated Samaritan’s dilemma game with variable entangling is studied in this work. The game is played in the cellular automata manner, i.e. with local and synchronous interaction. The game is assessed in fair and unfair contests, in noiseless scenarios and with disrupting quantum noise. PMID:28680654

  8. Modeling the potential spread of the recently identified non-native panther grouper (Chromileptes altivelis) in the Atlantic using a cellular automaton approach.

    Science.gov (United States)

    Johnston, Matthew W; Purkis, Sam J

    2013-01-01

    The Indo-pacific panther grouper (Chromileptes altiveli) is a predatory fish species and popular imported aquarium fish in the United States which has been recently documented residing in western Atlantic waters. To date, the most successful marine invasive species in the Atlantic is the lionfish (Pterois volitans/miles), which, as for the panther grouper, is assumed to have been introduced to the wild through aquarium releases. However, unlike lionfish, the panther grouper is not yet thought to have an established breeding population in the Atlantic. Using a proven modeling technique developed to track the lionfish invasion, presented is the first known estimation of the potential spread of panther grouper in the Atlantic. The employed cellular automaton-based computer model examines the life history of the subject species including fecundity, mortality, and reproductive potential and combines this with habitat preferences and physical oceanic parameters to forecast the distribution and periodicity of spread of this potential new invasive species. Simulations were examined for origination points within one degree of capture locations of panther grouper from the United States Geological Survey Nonindigenous Aquatic Species Database to eliminate introduction location bias, and two detailed case studies were scrutinized. The model indicates three primary locations where settlement is likely given the inputs and limits of the model; Jupiter Florida/Vero Beach, the Cape Hatteras Tropical Limit/Myrtle Beach South Carolina, and Florida Keys/Ten Thousand Islands locations. Of these locations, Jupiter Florida/Vero Beach has the highest settlement rate in the model and is indicated as the area in which the panther grouper is most likely to become established. This insight is valuable if attempts are to be made to halt this potential marine invasive species.

  9. Modeling the potential spread of the recently identified non-native panther grouper (Chromileptes altivelis in the Atlantic using a cellular automaton approach.

    Directory of Open Access Journals (Sweden)

    Matthew W Johnston

    Full Text Available The Indo-pacific panther grouper (Chromileptes altiveli is a predatory fish species and popular imported aquarium fish in the United States which has been recently documented residing in western Atlantic waters. To date, the most successful marine invasive species in the Atlantic is the lionfish (Pterois volitans/miles, which, as for the panther grouper, is assumed to have been introduced to the wild through aquarium releases. However, unlike lionfish, the panther grouper is not yet thought to have an established breeding population in the Atlantic. Using a proven modeling technique developed to track the lionfish invasion, presented is the first known estimation of the potential spread of panther grouper in the Atlantic. The employed cellular automaton-based computer model examines the life history of the subject species including fecundity, mortality, and reproductive potential and combines this with habitat preferences and physical oceanic parameters to forecast the distribution and periodicity of spread of this potential new invasive species. Simulations were examined for origination points within one degree of capture locations of panther grouper from the United States Geological Survey Nonindigenous Aquatic Species Database to eliminate introduction location bias, and two detailed case studies were scrutinized. The model indicates three primary locations where settlement is likely given the inputs and limits of the model; Jupiter Florida/Vero Beach, the Cape Hatteras Tropical Limit/Myrtle Beach South Carolina, and Florida Keys/Ten Thousand Islands locations. Of these locations, Jupiter Florida/Vero Beach has the highest settlement rate in the model and is indicated as the area in which the panther grouper is most likely to become established. This insight is valuable if attempts are to be made to halt this potential marine invasive species.

  10. Cellular automaton simulation of microstructure evolution during ...

    Indian Academy of Sciences (India)

    Unknown

    different composition and austenite grain size. Using the ..... Figure 1. Microstructures of 0⋅28% C steel heat treated samples: a. cooling rate 1⋅75°C/S and equivalent grain diameter .... qualitative predictions point to the essential soundness.

  11. Peculiarities of hardware implementation of generalized cellular tetra automaton

    OpenAIRE

    Аноприенко, Александр Яковлевич; Федоров, Евгений Евгениевич; Иваница, Сергей Васильевич; Альрабаба, Хамза

    2015-01-01

    Cellular automata are widely used in many fields of knowledge for the study of variety of complex real processes: computer engineering and computer science, cryptography, mathematics, physics, chemistry, ecology, biology, medicine, epidemiology, geology, architecture, sociology, theory of neural networks. Thus, cellular automata (CA) and tetra automata are gaining relevance taking into account the hardware and software solutions.Also it is marked a trend towards an increase in the number of p...

  12. Probing Cellular Dynamics with Mesoscopic Simulations

    DEFF Research Database (Denmark)

    Shillcock, Julian C.

    2010-01-01

    Cellular processes span a huge range of length and time scales from the molecular to the near-macroscopic. Understanding how effects on one scale influence, and are themselves influenced by, those on lower and higher scales is a critical issue for the construction of models in Systems Biology....... Advances in computing hardware and software now allow explicit simulation of some aspects of cellular dynamics close to the molecular scale. Vesicle fusion is one example of such a process. Experiments, however, typically probe cellular behavior from the molecular scale up to microns. Standard particle...... soon be coupled to Mass Action models allowing the parameters in such models to be continuously tuned according to the finer resolution simulation. This will help realize the goal of a computational cellular simulation that is able to capture the dynamics of membrane-associated processes...

  13. Cellular automaton model for hydrogen transport dynamics through metallic surface

    International Nuclear Information System (INIS)

    Shimura, K.; Yamaguchi, K.; Terai, T.; Yamawaki, M.

    2002-01-01

    Hydrogen re-emission and re-combination at the surface of first wall materials are a crucial issue for the understanding of the fuel recycling and for the tritium inventory in plasma facing materials. It is know to be difficult to model the transient behaviour of those processes due to their complex time-transient nature. However, cellular automata (CA) are powerful tools to model such complex systems because of their nature of discreteness in both dependent and independent variables. Then the system can be represented by the fully local interactions between cells. For that reason, complex physical and chemical systems can be described by fairly simple manner. In this study, the kinetics of desorption of adsorbed hydrogen from an ideal metallic surface is modelled in CA. Thermal desorption is simulated with this model and the comparison with the theory of rate processes is performed to identify the validity of this model. The overall results show that this model is reasonable to express the desorption kinetics

  14. Algorithmic crystal chemistry: A cellular automata approach

    International Nuclear Information System (INIS)

    Krivovichev, S. V.

    2012-01-01

    Atomic-molecular mechanisms of crystal growth can be modeled based on crystallochemical information using cellular automata (a particular case of finite deterministic automata). In particular, the formation of heteropolyhedral layered complexes in uranyl selenates can be modeled applying a one-dimensional three-colored cellular automaton. The use of the theory of calculations (in particular, the theory of automata) in crystallography allows one to interpret crystal growth as a computational process (the realization of an algorithm or program with a finite number of steps).

  15. A hybrid finite-element and cellular-automaton framework for modeling 3D microstructure of Ti–6Al–4V alloy during solid–solid phase transformation in additive manufacturing

    Science.gov (United States)

    Chen, Shaohua; Xu, Yaopengxiao; Jiao, Yang

    2018-06-01

    Additive manufacturing such as selective laser sintering and electron beam melting has become a popular technique which enables one to build near-net-shape product from packed powders. The performance and properties of the manufactured product strongly depends on its material microstructure, which is in turn determined by the processing conditions including beam power density, spot size, scanning speed and path etc. In this paper, we develop a computational framework that integrates the finite element method (FEM) and cellular automaton (CA) simulation to model the 3D microstructure of additively manufactured Ti–6Al–4V alloy, focusing on the β → α + β transition pathway in a consolidated alloy region as the power source moves away from this region. Specifically, the transient temperature field resulted from a scanning laser/electron beam following a zig-zag path is first obtained by solving nonlinear heat transfer equations using the FEM. Next, a CA model for the β → α + β phase transformation in the consolidated alloy is developed which explicitly takes into account the temperature dependent heterogeneous nucleation and anisotropic growth of α grains from the parent β phase field. We verify our model by reproducing the overall transition kinetics predicted by the Johnson–Mehl–Avrami–Kolmogorov theory under a typical processing condition and by quantitatively comparing our simulation results with available experimental data. The utility of the model is further demonstrated by generating large-field realistic 3D alloy microstructures for subsequent structure-sensitive micro-mechanical analysis. In addition, we employ our model to generate a wide spectrum of alloy microstructures corresponding to different processing conditions for establishing quantitative process-structure relations for the system.

  16. Cellular-automata method for phase unwrapping

    International Nuclear Information System (INIS)

    Ghiglia, D.C.; Mastin, G.A.; Romero, L.A.

    1987-01-01

    Research into two-dimensional phase unwrapping has uncovered interesting and troublesome inconsistencies that cause path-dependent results. Cellular automata, which are simple, discrete mathematical systems, offered promise of computation in nondirectional, parallel manner. A cellular automaton was discovered that can unwrap consistent phase data in n dimensions in a path-independent manner and can automatically accommodate noise-induced (pointlike) inconsistencies and arbitrary boundary conditions (region partitioning). For data with regional (nonpointlike) inconsistencies, no phase-unwrapping algorithm will converge, including the cellular-automata approach. However, the automata method permits more simple visualization of the regional inconsistencies. Examples of its behavior on one- and two-dimensional data are presented

  17. Model checking of time Petri nets using the state class timed automaton

    DEFF Research Database (Denmark)

    Lime, Didier; Roux, Olivier H.

    2006-01-01

    In this paper, we propose a method for building the state class graph of a bounded time Petri net (TPN) as a timed automaton (TA), which we call the state class timed automaton. We consider bounded TPN, whose underlying net is not necessarily bounded. We prove that our translation preserves the b...

  18. A Local Land Use Competition Cellular Automata Model and Its Application

    Directory of Open Access Journals (Sweden)

    Jun Yang

    2016-06-01

    Full Text Available Cellular automaton (CA is an important method in land use and cover change studies, however, the majority of research focuses on the discovery of macroscopic factors affecting LUCC, which results in ignoring the local effects within the neighborhoods. This paper introduces a Local Land Use Competition Cellular Automata (LLUC-CA model, based on local land use competition, land suitability evaluation, demand analysis of the different land use types, and multi-target land use competition allocation algorithm to simulate land use change at a micro level. The model is applied to simulate land use changes at Jinshitan National Tourist Holiday Resort from 1988 to 2012. The results show that the simulation accuracies were 64.46%, 77.21%, 85.30% and 99.14% for the agricultural land, construction land, forestland and water, respectively. In addition, comparing the simulation results of the LLUC-CA and CA-Markov model with the real land use data, their overall spatial accuracies were found to be 88.74% and 86.82%, respectively. In conclusion, the results from this study indicated that the model was an acceptable method for the simulation of large-scale land use changes, and the approach used here is applicable to analyzing the land use change driven forces and assist in decision-making.

  19. Reliable self-replicating machines in asynchronous cellular automata.

    Science.gov (United States)

    Lee, Jia; Adachi, Susumu; Peper, Ferdinand

    2007-01-01

    We propose a self-replicating machine that is embedded in a two-dimensional asynchronous cellular automaton with von Neumann neighborhood. The machine dynamically encodes its shape into description signals, and despite the randomness of cell updating, it is able to successfully construct copies of itself according to the description signals. Self-replication on asynchronously updated cellular automata may find application in nanocomputers, where reconfigurability is an essential property, since it allows avoidance of defective parts and simplifies programming of such computers.

  20. Simulating flaring events in complex active regions driven by observed magnetograms

    Science.gov (United States)

    Dimitropoulou, M.; Isliker, H.; Vlahos, L.; Georgoulis, M. K.

    2011-05-01

    Context. We interpret solar flares as events originating in active regions that have reached the self organized critical state, by using a refined cellular automaton model with initial conditions derived from observations. Aims: We investigate whether the system, with its imposed physical elements, reaches a self organized critical state and whether well-known statistical properties of flares, such as scaling laws observed in the distribution functions of characteristic parameters, are reproduced after this state has been reached. Methods: To investigate whether the distribution functions of total energy, peak energy and event duration follow the expected scaling laws, we first applied a nonlinear force-free extrapolation that reconstructs the three-dimensional magnetic fields from two-dimensional vector magnetograms. We then locate magnetic discontinuities exceeding a threshold in the Laplacian of the magnetic field. These discontinuities are relaxed in local diffusion events, implemented in the form of cellular automaton evolution rules. Subsequent loading and relaxation steps lead the system to self organized criticality, after which the statistical properties of the simulated events are examined. Physical requirements, such as the divergence-free condition for the magnetic field vector, are approximately imposed on all elements of the model. Results: Our results show that self organized criticality is indeed reached when applying specific loading and relaxation rules. Power-law indices obtained from the distribution functions of the modeled flaring events are in good agreement with observations. Single power laws (peak and total flare energy) are obtained, as are power laws with exponential cutoff and double power laws (flare duration). The results are also compared with observational X-ray data from the GOES satellite for our active-region sample. Conclusions: We conclude that well-known statistical properties of flares are reproduced after the system has

  1. Orientation selection of equiaxed dendritic growth by three-dimensional cellular automaton model

    Energy Technology Data Exchange (ETDEWEB)

    Wei Lei [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072 (China); Lin Xin, E-mail: xlin@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072 (China); Wang Meng; Huang Weidong [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072 (China)

    2012-07-01

    A three-dimensional (3-D) adaptive mesh refinement (AMR) cellular automata (CA) model is developed to simulate the equiaxed dendritic growth of pure substance. In order to reduce the mesh induced anisotropy by CA capture rules, a limited neighbor solid fraction (LNSF) method is presented. It is shown that the LNSF method reduced the mesh induced anisotropy based on the simulated morphologies for isotropic interface free energy. An expansion description using two interface free energy anisotropy parameters ({epsilon}{sub 1}, {epsilon}{sub 2}) is used in the present 3-D CA model. It is illustrated by present 3-D CA model that the positive {epsilon}{sub 1} favors the dendritic growth with the Left-Pointing-Angle-Bracket 100 Right-Pointing-Angle-Bracket preferred directions, and negative {epsilon}{sub 2} favors dendritic growth with the Left-Pointing-Angle-Bracket 110 Right-Pointing-Angle-Bracket preferred directions, which has a good agreement with the prediction of the spherical plot of the inverse of the interfacial stiffness. The dendritic growths with the orientation selection between Left-Pointing-Angle-Bracket 100 Right-Pointing-Angle-Bracket and Left-Pointing-Angle-Bracket 110 Right-Pointing-Angle-Bracket are also discussed using the different {epsilon}{sub 1} with {epsilon}{sub 2}=-0.02. It is found that the simulated morphologies by present CA model are as expected from the minimum stiffness criterion.

  2. Cellular Particle Dynamics simulation of biomechanical relaxation processes of multi-cellular systems

    Science.gov (United States)

    McCune, Matthew; Kosztin, Ioan

    2013-03-01

    Cellular Particle Dynamics (CPD) is a theoretical-computational-experimental framework for describing and predicting the time evolution of biomechanical relaxation processes of multi-cellular systems, such as fusion, sorting and compression. In CPD, cells are modeled as an ensemble of cellular particles (CPs) that interact via short range contact interactions, characterized by an attractive (adhesive interaction) and a repulsive (excluded volume interaction) component. The time evolution of the spatial conformation of the multicellular system is determined by following the trajectories of all CPs through numerical integration of their equations of motion. Here we present CPD simulation results for the fusion of both spherical and cylindrical multi-cellular aggregates. First, we calibrate the relevant CPD model parameters for a given cell type by comparing the CPD simulation results for the fusion of two spherical aggregates to the corresponding experimental results. Next, CPD simulations are used to predict the time evolution of the fusion of cylindrical aggregates. The latter is relevant for the formation of tubular multi-cellular structures (i.e., primitive blood vessels) created by the novel bioprinting technology. Work supported by NSF [PHY-0957914]. Computer time provided by the University of Missouri Bioinformatics Consortium.

  3. HEURISTIC METHOD FOR LOW POWER RACE-FREE STATE-ASSIGNMENT OF AN ASYNGHRONOUS AUTOMATON

    Directory of Open Access Journals (Sweden)

    Yu. V. Pottosin

    2016-01-01

    Full Text Available The problem of race free state-assignment of an asynchronous automaton minimizing the switching activity of memory elements in an implementing circuit is considered. A heuristic method to solve this problem for an asynchronous automaton is suggested where the critical races between memory elements of the implementing circuit are eliminated.

  4. Cellular automaton model of crowd evacuation inspired by slime mould

    Science.gov (United States)

    Kalogeiton, V. S.; Papadopoulos, D. P.; Georgilas, I. P.; Sirakoulis, G. Ch.; Adamatzky, A. I.

    2015-04-01

    In all the living organisms, the self-preservation behaviour is almost universal. Even the most simple of living organisms, like slime mould, is typically under intense selective pressure to evolve a response to ensure their evolution and safety in the best possible way. On the other hand, evacuation of a place can be easily characterized as one of the most stressful situations for the individuals taking part on it. Taking inspiration from the slime mould behaviour, we are introducing a computational bio-inspired model crowd evacuation model. Cellular Automata (CA) were selected as a fully parallel advanced computation tool able to mimic the Physarum's behaviour. In particular, the proposed CA model takes into account while mimicking the Physarum foraging process, the food diffusion, the organism's growth, the creation of tubes for each organism, the selection of optimum tube for each human in correspondence to the crowd evacuation under study and finally, the movement of all humans at each time step towards near exit. To test the model's efficiency and robustness, several simulation scenarios were proposed both in virtual and real-life indoor environments (namely, the first floor of office building B of the Department of Electrical and Computer Engineering of Democritus University of Thrace). The proposed model is further evaluated in a purely quantitative way by comparing the simulation results with the corresponding ones from the bibliography taken by real data. The examined fundamental diagrams of velocity-density and flow-density are found in full agreement with many of the already published corresponding results proving the adequacy, the fitness and the resulting dynamics of the model. Finally, several real Physarum experiments were conducted in an archetype of the aforementioned real-life environment proving at last that the proposed model succeeded in reproducing sufficiently the Physarum's recorded behaviour derived from observation of the aforementioned

  5. The MatchIT Automaton

    DEFF Research Database (Denmark)

    Weyland, Mathias; Fellermann, Harold; Hadorn, Maik

    2013-01-01

    In this paper, we propose the MATCHIT Automaton (MA), a theoretical framework that shows how to improve the yield of the synthesis of chemical polymer reactions. This is achieved by separating sub-steps of the path of syn- thesis into compartments. We use chemical containers (chemtainers) to carr...... reticulum and the Golgi apparatus, and we show how this compartmentalization can be exploited for the synthesis of branched polymers. Lastly, we show exam- ples of artificial branched polymers and discuss how the MA can be configured to synthesize them with maximal yield....

  6. Cellular automata in photonic cavity arrays.

    Science.gov (United States)

    Li, Jing; Liew, T C H

    2016-10-31

    We propose theoretically a photonic Turing machine based on cellular automata in arrays of nonlinear cavities coupled with artificial gauge fields. The state of the system is recorded making use of the bistability of driven cavities, in which losses are fully compensated by an external continuous drive. The sequential update of the automaton layers is achieved automatically, by the local switching of bistable states, without requiring any additional synchronization or temporal control.

  7. CAFE simulation of columnar-to-equiaxed transition in Al-7wt%Si alloys directionally solidified under microgravity

    Science.gov (United States)

    Liu, D. R.; Mangelinck-Noël, N.; Gandin, Ch-A.; Zimmermann, G.; Sturz, L.; Nguyen Thi, H.; Billia, B.

    2016-03-01

    A two-dimensional multi-scale cellular automaton - finite element (CAFE) model is used to simulate grain structure evolution and microsegregation formation during solidification of refined Al-7wt%Si alloys under microgravity. The CAFE simulations are first qualitatively compared with the benchmark experimental data under microgravity. Qualitative agreement is obtained for the position of columnar to equiaxed transition (CET) and the CET transition mode (sharp or progressive). Further comparisons of the distributions of grain elongation factor and equivalent diameter are conducted and reveal a fair quantitative agreement.

  8. Research of the method of pseudo-random number generation based on asynchronous cellular automata with several active cells

    Directory of Open Access Journals (Sweden)

    Bilan Stepan

    2017-01-01

    Full Text Available To date, there are many tasks that are aimed at studying the dynamic changes in physical processes. These tasks do not give advance known result. The solution of such problems is based on the construction of a dynamic model of the object. Successful structural and functional implementation of the object model can give a positive result in time. This approach uses the task of constructing artificial biological objects. To solve such problems, pseudo-random number generators are used, which also find wide application for information protection tasks. Such generators should have good statistical properties and give a long repetition period of the generated pseudo-random bit sequence. This work is aimed at improving these characteristics. The paper considers the method of forming pseudo-random sequences of numbers on the basis of aperiodic cellular automata with two active cells. A pseudo-random number generator is proposed that generates three bit sequences. The first two bit sequences are formed by the corresponding two active cells in the cellular automaton. The third bit sequence is the result of executing the XOR function over the bits of the first two sequences and it has better characteristics compared to them. The use of cellular automata with two active cells allowed to improve the statistical properties of the formed bit sequence, as well as its repetition period. This is proved by using graphical tests for generators built based on cellular automata using the neighborhoods of von Neumann and Moore. The tests showed high efficiency of the generator based on an asynchronous cellular automaton with the neighborhood of Moore. The proposed pseudo-random number generators have good statistical properties, which makes it possible to use them in information security systems, as well as for simulation tasks of various dynamic processes.

  9. Surface Dynamic Process Simulation with the Use of Cellular Automata

    International Nuclear Information System (INIS)

    Adamska-Szatko, M.; Bala, J.

    2010-01-01

    Cellular automata are known for many applications, especially for physical and biological simulations. Universal cellular automata can be used for modelling complex natural phenomena. The paper presents simulation of surface dynamic process. Simulation uses 2-dimensional cellular automata algorithm. Modelling and visualisation were created by in-house developed software with standard OpenGL graphic library. (authors)

  10. Cellular Automata Simulation for Wealth Distribution

    Science.gov (United States)

    Lo, Shih-Ching

    2009-08-01

    Wealth distribution of a country is a complicate system. A model, which is based on the Epstein & Axtell's "Sugars cape" model, is presented in Netlogo. The model considers the income, age, working opportunity and salary as control variables. There are still other variables should be considered while an artificial society is established. In this study, a more complicate cellular automata model for wealth distribution model is proposed. The effects of social welfare, tax, economical investment and inheritance are considered and simulated. According to the cellular automata simulation for wealth distribution, we will have a deep insight of financial policy of the government.

  11. CAFE simulation of columnar-to-equiaxed transition in Al-7wt%Si alloys directionally solidified under microgravity

    International Nuclear Information System (INIS)

    Liu, D R; Mangelinck-Noël, N; Thi, H Nguyen; Billia, B; Gandin, Ch-A; Zimmermann, G; Sturz, L

    2016-01-01

    A two-dimensional multi-scale cellular automaton - finite element (CAFE) model is used to simulate grain structure evolution and microsegregation formation during solidification of refined Al-7wt%Si alloys under microgravity. The CAFE simulations are first qualitatively compared with the benchmark experimental data under microgravity. Qualitative agreement is obtained for the position of columnar to equiaxed transition (CET) and the CET transition mode (sharp or progressive). Further comparisons of the distributions of grain elongation factor and equivalent diameter are conducted and reveal a fair quantitative agreement. (paper)

  12. Exact quantification of the complexity of spacewise pattern growth in cellular automata

    International Nuclear Information System (INIS)

    Freire, Joana G; Gallas, Jason A C; Brison, Owen J

    2009-01-01

    We analyze the two possible ways of simulating complex systems with cellular automata: by using the familiar timewise updating or by using the complementary spacewise updating. Both updating algorithms operate on identical sets of initial conditions defining the state of the automaton. While timewise growth generally probes just vanishingly small sets of initial conditions producing statistical samples of the asymptotic attractors, spacewise growth operates with much restricted sets which allow one to simulate them all, exhaustively. Our main result is the derivation of an exact analytical formula to quantify precisely one of the two sources of algorithmic complexity of spacewise detection of the complete set of attractors for elementary 1D cellular automata with generic non-periodic architectures of any arbitrary size. The formula gives the total number of initial conditions that need to be investigated to locate rigorously all possible patterns for any given rule. As simple applications, we illustrate how this knowledge may be used (i) to uncover missing patterns in previous classifications in the literature and (ii) to obtain surprisingly novel patterns that are totally unreachable with the time-honored technique of artificially imposing spatially periodic boundary conditions.

  13. Multidimensional cellular automata and generalization of Fekete's lemma

    Directory of Open Access Journals (Sweden)

    Silvio Capobianco

    2008-08-01

    Full Text Available Fekete's lemma is a well known combinatorial result on number sequences: we extend it to functions defined on $d$-tuples of integers. As an application of the new variant, we show that nonsurjective $d$-dimensional cellular automata are characterized by loss of arbitrarily much information on finite supports, at a growth rate greater than that of the support's boundary determined by the automaton's neighbourhood index.

  14. Bin packing problem solution through a deterministic weighted finite automaton

    Science.gov (United States)

    Zavala-Díaz, J. C.; Pérez-Ortega, J.; Martínez-Rebollar, A.; Almanza-Ortega, N. N.; Hidalgo-Reyes, M.

    2016-06-01

    In this article the solution of Bin Packing problem of one dimension through a weighted finite automaton is presented. Construction of the automaton and its application to solve three different instances, one synthetic data and two benchmarks are presented: N1C1W1_A.BPP belonging to data set Set_1; and BPP13.BPP belonging to hard28. The optimal solution of synthetic data is obtained. In the first benchmark the solution obtained is one more container than the ideal number of containers and in the second benchmark the solution is two more containers than the ideal solution (approximately 2.5%). The runtime in all three cases was less than one second.

  15. Investigation of the Practical Possibility of Solving Problems on Generalized Cellular Automata Associated with Cryptanalysis by Mean Algebraic Methods

    Directory of Open Access Journals (Sweden)

    P. G. Klyucharev

    2017-01-01

    Full Text Available A number of previous author’s papers proposed methods for constructing various cryptographic algorithms, including block ciphers and cryptographic hash functions, based on generalized cellular automata. This one is aimed at studying a possibility to use the algebraic cryptanalysis methods related to the construction of Gröbner bases for the generalized cellular automata to be applied in cryptography, i.e. this paper studies the possibility for using algebraic cryptanalysis methods to solve the problems of inversion of a generalized cellular automaton and recovering the key of such an automaton.If the cryptographic algorithm is represented as a system of polynomial equations over a certain finite field, then its breach is reduced to solving this system with respect to the key. Although the problem of solving a system of polynomial equations in a finite field is NP-difficult in the general case, the solution of a particular system can have low computational cost.Cryptanalysis based on the construction of a system of polynomial equations that links plain text, cipher-text and key, and its solution by algebraic methods, is usually called algebraic cryptanalysis. Among the main methods to solve systems of polynomial equations are those to construct Gröbner bases.Cryptanalysis of ciphers and hash functions based on generalized cellular automata can be reduced to various problems. We will consider two such problems: the problem of inversion of a generalized cellular automaton, which, in case we know the values of the cells after k iterations, enables us to find the initial values. And the task of recovering the key, which is to find the initial values of the remaining cells, using the cell values after k steps and the initial values of a part of the cells.A computational experiment was carried out to solve the two problems above stated in order to determine the maximum size of a generalized cellular automaton for which the solution of these

  16. Clarification of complex phenomena in nuclear plants present status and future trend of fluid analysis by cellular automaton methods

    International Nuclear Information System (INIS)

    Kato, Yasuyoshi

    1999-01-01

    Since most of complex phenomena comprise of various elementary processes e.g., fluid flow, heat conduction, phase transition, chemical reaction, structural deformation, and these processes interact each other nonlinearly, the complex phenomena cannot be easily clarified by such the conventional topdown approaches as describe phenomena by using differential equations. In contrast to the topdown approaches where the differential equations are located at the top of the analysis procedures, these are bottomup approaches where phenomena are reproduced by local interaction of particles on cells. Cellular automata are one of the typical bottomup approaches. The basic principle, computer simulation results, and massively parallel processors for the cellular automata are reviewed and perspectives of the bottomup approach are discussed on clarification of the complex phenomena in nuclear plants. The computer simulations mainly deal with fluid flows and phase interfacial phenomena. (author)

  17. Number-conserving cellular automata with a von Neumann neighborhood of range one

    International Nuclear Information System (INIS)

    Wolnik, Barbara; Dzedzej, Adam; Baetens, Jan M; De Baets, Bernard

    2017-01-01

    We present necessary and sufficient conditions for a cellular automaton with a von Neumann neighborhood of range one to be number-conserving. The conditions are formulated for any dimension and for any set of states containing zero. The use of the geometric structure of the von Neumann neighborhood allows for computationally tractable conditions even in higher dimensions. (paper)

  18. Geometrical automata for two phase flow simulation

    International Nuclear Information System (INIS)

    Herrero, V.; Guido-Lavalle, G.; Clausse, A.

    1996-01-01

    An automaton is an entity defined by a mathematical state which changes following iterative rules representing the interaction with the neighborhood. A model of automata for two-phase flow simulation consisting in a field of disks which are allowed to change their radii and move in a plane is presented. The model is more general than the classical cellular automata in two respects: (1) the grid of cellular automata is dismissed in favor of a trajectory generator; and (2) the rules of interaction involve parameters intended to represent some of the most relevant variables governing the actual physical interactions between phases. Computational experiments show that the algorithm captures the essential physics underlying two-phase flow problems such as bubbly-slug pattern transition and void fraction development along tubes. A comparison with experimental data of void fraction profiles is presented, showing excellent agreement. (orig.)

  19. Computing aggregate properties of preimages for 2D cellular automata.

    Science.gov (United States)

    Beer, Randall D

    2017-11-01

    Computing properties of the set of precursors of a given configuration is a common problem underlying many important questions about cellular automata. Unfortunately, such computations quickly become intractable in dimension greater than one. This paper presents an algorithm-incremental aggregation-that can compute aggregate properties of the set of precursors exponentially faster than naïve approaches. The incremental aggregation algorithm is demonstrated on two problems from the two-dimensional binary Game of Life cellular automaton: precursor count distributions and higher-order mean field theory coefficients. In both cases, incremental aggregation allows us to obtain new results that were previously beyond reach.

  20. Game of Life Cellular Automata

    CERN Document Server

    Adamatzky, Andrew

    2010-01-01

    In the late 1960s, British mathematician John Conway invented a virtual mathematical machine that operates on a two-dimensional array of square cell. Each cell takes two states, live and dead. The cells' states are updated simultaneously and in discrete time. A dead cell comes to life if it has exactly three live neighbours. A live cell remains alive if two or three of its neighbours are alive, otherwise the cell dies. Conway's Game of Life became the most programmed solitary game and the most known cellular automaton. The book brings together results of forty years of study into computational

  1. Application of neural networks and cellular automata to calorimetric problems

    International Nuclear Information System (INIS)

    Brenton, V.; Fonvieille, H.; Guicheney, C.; Jousset, J.; Roblin, Y.; Tamin, F.; Grenier, P.

    1994-09-01

    Computing techniques based on parallel processing have been used to treat the information from the electromagnetic calorimeters in SLAC experiments E142/E143. Cluster finding and separation of overlapping showers are performed by a cellular automaton, pion and electron identification is done by using a multilayered neural network. Both applications are presented and their resulting performances are shown to be improved compared to more standard approaches. (author)

  2. Invariant strings and pattern-recognizing properties of one-dimensional cellular automata

    International Nuclear Information System (INIS)

    Jen, E.

    1986-01-01

    A cellular automaton is a discrete dynamical system whose evolution is governed by a deterministic rule involving local interactions. It is shown that given an arbitrary string of values and an arbitry neighborhood size (representing the range of interaction), a simple procedure can be used to find the fules of that neighborhood size under which the string is unvarian. The set of nearestneighbor rules for which invariant strings exist is completely specified, as is the set of strings invariant under each such rule. For any automaton rule, an associated ''filtering'' rule is defined for which the only attractors are spatial sequences consisting of concatenations of invariant strings. A result is provided defining the rule of minimum neighborhood size for which an arbitrrily chosen string is the unique invariant string. The applications of filtering rules to pttern recognition problems are discussed

  3. Cellular Automata for Modeling the field-scale erosion

    International Nuclear Information System (INIS)

    Diaz Suarez, Jorge; Bagarotti Marin, Angel; Ruiz Perez, Maria Elena

    2008-01-01

    Full text: The Cellular Automaton (CA) is a system used discrete dynamic modeling of many physical systems. Their fundamental properties are the interaction at the local level, homogeneity and parallelism. It has been used as a secondary for the simulation of large systems where the use of equations in partial derivatives is complex and costly from the computational point of view. On the other hand, the high complexity of spatial interaction in the processes involved in the erosion-transport-deposition of sediments at field level, considerably limiting the use of base models physics. The objective of this study is to model the main processes involved in erosion water supply of soils through the use of the CAMELot system, based on an extension of the original paradigm of the CA. The CAMELot system has been used in the simulation of systems of large spatial extent, where the laws of local interaction between automata have a deep physical sense. This system guarantees both the input of the necessary specifications and simulation in parallel, as the visualization and the general management of the system. They are exposed to each of the submodels used in it and the overall dynamics of the system is analyzed. (author)

  4. Simulating the behavior of patients who leave a public hospital emergency department without being seen by a physician: a cellular automaton and agent-based framework

    Directory of Open Access Journals (Sweden)

    Milad Yousefi

    2018-01-01

    Full Text Available The objective of this study was to develop an agent based modeling (ABM framework to simulate the behavior of patients who leave a public hospital emergency department (ED without being seen (LWBS. In doing so, the study complements computer modeling and cellular automata (CA techniques to simulate the behavior of patients in an ED. After verifying and validating the model by comparing it with data from a real case study, the significance of four preventive policies including increasing number of triage nurses, fast-track treatment, increasing the waiting room capacity and reducing treatment time were investigated by utilizing ordinary least squares regression. After applying the preventing policies in ED, an average of 42.14% reduction in the number of patients who leave without being seen and 6.05% reduction in the average length of stay (LOS of patients was reported. This study is the first to apply CA in an ED simulation. Comparing the average LOS before and after applying CA with actual times from emergency department information system showed an 11% improvement. The simulation results indicated that the most effective approach to reduce the rate of LWBS is applying fast-track treatment. The ABM approach represents a flexible tool that can be constructed to reflect any given environment. It is also a support system for decision-makers to assess the relative impact of control strategies.

  5. Simulating the behavior of patients who leave a public hospital emergency department without being seen by a physician: a cellular automaton and agent-based framework.

    Science.gov (United States)

    Yousefi, Milad; Yousefi, Moslem; Fogliatto, F S; Ferreira, R P M; Kim, J H

    2018-01-11

    The objective of this study was to develop an agent based modeling (ABM) framework to simulate the behavior of patients who leave a public hospital emergency department (ED) without being seen (LWBS). In doing so, the study complements computer modeling and cellular automata (CA) techniques to simulate the behavior of patients in an ED. After verifying and validating the model by comparing it with data from a real case study, the significance of four preventive policies including increasing number of triage nurses, fast-track treatment, increasing the waiting room capacity and reducing treatment time were investigated by utilizing ordinary least squares regression. After applying the preventing policies in ED, an average of 42.14% reduction in the number of patients who leave without being seen and 6.05% reduction in the average length of stay (LOS) of patients was reported. This study is the first to apply CA in an ED simulation. Comparing the average LOS before and after applying CA with actual times from emergency department information system showed an 11% improvement. The simulation results indicated that the most effective approach to reduce the rate of LWBS is applying fast-track treatment. The ABM approach represents a flexible tool that can be constructed to reflect any given environment. It is also a support system for decision-makers to assess the relative impact of control strategies.

  6. A Five Species Cyclically Dominant Evolutionary Game with Fixed Direction: A New Way to Produce Self-Organized Spatial Patterns

    Directory of Open Access Journals (Sweden)

    Yibin Kang

    2016-08-01

    Full Text Available Cyclically dominant systems are hot issues in academia, and they play an important role in explaining biodiversity in Nature. In this paper, we construct a five-strategy cyclically dominant system. Each individual in our system changes its strategy along a fixed direction. The dominant strategy can promote a change in the dominated strategy, and the dominated strategy can block a change in the dominant strategy. We use mean-field theory and cellular automaton simulation to discuss the evolving characters of the system. In the cellular automaton simulation, we find the emergence of spiral waves on spatial patterns without a migration rate, which suggests a new way to produce self-organized spatial patterns.

  7. Factorization, reduction and embedding in integrable cellular automata

    International Nuclear Information System (INIS)

    Kuniba, Atsuo; Takagi, Taichiro; Takenouchi, Akira

    2004-01-01

    Factorized dynamics in soliton cellular automata with quantum group symmetry is identified with a motion of particles and anti-particles exhibiting pair creation and annihilation. An embedding scheme is presented showing that the D (1) n -automaton contains, as certain subsectors, the box-ball systems and all the other automata associated with the crystal bases of non-exceptional affine Lie algebras. The results extend the earlier ones to higher representations by a certain reduction and to a wider class of boundary conditions

  8. An extinction-survival-type phase transition in the probabilistic cellular automaton p182-q200

    International Nuclear Information System (INIS)

    Mendonca, J R G; Oliveira, M J de

    2011-01-01

    We investigate the critical behaviour of a probabilistic mixture of cellular automata (CA) rules 182 and 200 (in Wolfram's enumeration scheme) by mean-field analysis and Monte Carlo simulations. We found that as we switch off one CA and switch on the other by the variation of the single parameter of the model, the probabilistic CA (PCA) goes through an extinction-survival-type phase transition, and the numerical data indicate that it belongs to the directed percolation universality class of critical behaviour. The PCA displays a characteristic stationary density profile and a slow, diffusive dynamics close to the pure CA 200 point that we discuss briefly. Remarks on an interesting related stochastic lattice gas are addressed in the conclusions.

  9. Localizations in cellular automata with mutualistic excitation rules

    International Nuclear Information System (INIS)

    Adamatzky, Andrew

    2009-01-01

    Every cell of two-dimensional cellular automaton with eight-cell neighborhood takes three states: resting, excited and refractory, and updates excited to refractory and refractory to resting states unconditionally. A resting cell excites depending on number of excited and refractory neighbors. We made exhaustive study of spatio-temporal excitation dynamics for all rules of this type and selected several classes of rules. The classes supporting self-localizations are studied in details. We uncover basic types of mobile (gliders) and stationary localizations, and characterize their morphology and dynamics.

  10. A cellular automata model of Ebola virus dynamics

    Science.gov (United States)

    Burkhead, Emily; Hawkins, Jane

    2015-11-01

    We construct a stochastic cellular automaton (SCA) model for the spread of the Ebola virus (EBOV). We make substantial modifications to an existing SCA model used for HIV, introduced by others and studied by the authors. We give a rigorous analysis of the similarities between models due to the spread of virus and the typical immune response to it, and the differences which reflect the drastically different timing of the course of EBOV. We demonstrate output from the model and compare it with clinical data.

  11. An extinction-survival-type phase transition in the probabilistic cellular automaton p182-q200

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, J R G; Oliveira, M J de, E-mail: jricardo@usp.br, E-mail: oliveira@if.usp.br [Instituto de Fisica, Universidade de Sao Paulo, Rua do Matao, Travessa R 187, Cidade Universitaria 05508-090, Sao Paulo (Brazil)

    2011-04-15

    We investigate the critical behaviour of a probabilistic mixture of cellular automata (CA) rules 182 and 200 (in Wolfram's enumeration scheme) by mean-field analysis and Monte Carlo simulations. We found that as we switch off one CA and switch on the other by the variation of the single parameter of the model, the probabilistic CA (PCA) goes through an extinction-survival-type phase transition, and the numerical data indicate that it belongs to the directed percolation universality class of critical behaviour. The PCA displays a characteristic stationary density profile and a slow, diffusive dynamics close to the pure CA 200 point that we discuss briefly. Remarks on an interesting related stochastic lattice gas are addressed in the conclusions.

  12. Application of neural networks and cellular automata to calorimetric problems

    Energy Technology Data Exchange (ETDEWEB)

    Brenton, V; Fonvieille, H; Guicheney, C; Jousset, J; Roblin, Y; Tamin, F; Grenier, P

    1994-09-01

    Computing techniques based on parallel processing have been used to treat the information from the electromagnetic calorimeters in SLAC experiments E142/E143. Cluster finding and separation of overlapping showers are performed by a cellular automaton, pion and electron identification is done by using a multilayered neural network. Both applications are presented and their resulting performances are shown to be improved compared to more standard approaches. (author). 9 refs.; Submitted to Nuclear Instruments and Methods (NL).

  13. Cellular automata for spatiotemporal pattern formation from reaction–diffusion partial differential equations

    International Nuclear Information System (INIS)

    Ohmori, Shousuke; Yamazaki, Yoshihiro

    2016-01-01

    Ultradiscrete equations are derived from a set of reaction–diffusion partial differential equations, and cellular automaton rules are obtained on the basis of the ultradiscrete equations. Some rules reproduce the dynamical properties of the original reaction–diffusion equations, namely, bistability and pulse annihilation. Furthermore, other rules bring about soliton-like preservation and periodic pulse generation with a pacemaker, which are not obtained from the original reaction–diffusion equations. (author)

  14. Periodical cicadas: A minimal automaton model

    Science.gov (United States)

    de O. Cardozo, Giovano; de A. M. M. Silvestre, Daniel; Colato, Alexandre

    2007-08-01

    The Magicicada spp. life cycles with its prime periods and highly synchronized emergence have defied reasonable scientific explanation since its discovery. During the last decade several models and explanations for this phenomenon appeared in the literature along with a great deal of discussion. Despite this considerable effort, there is no final conclusion about this long standing biological problem. Here, we construct a minimal automaton model without predation/parasitism which reproduces some of these aspects. Our results point towards competition between different strains with limited dispersal threshold as the main factor leading to the emergence of prime numbered life cycles.

  15. Learning automaton newtork and its dynamics. Gakushu automaton network to sono dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Quan, F [Hiroshima-Denki Institute of Technology, Hiroshima (Jpaan); Unno, F; Hirata, H [Chiba Univ., Chiba (Japan)

    1991-10-20

    In order to construct a distributed processing system having learning automata as autonomous elements, a reinforcement learning network of the automaton is proposed and it{prime}s dynamics is investigated. In this paper, it is attempted to add another level of meaning to computational cooperativity by using a reinforcement learning network with generalized leaning automata. The collection of learning automata in the team situation acts as self-interested agents that work toward improving their performance with respect to their individual preference ordering. In the global state space of the network, the case of partially synchronous stochastic process is considered. In this case, the existence of mean field is shown and a reinforcement learning algorithm which can make the dynamics on the average reinforcement trajectory is presented. This algorithm is shown to have a high convergence speed as a result of a simple experiment. 14 refs., 9 figs.

  16. LOW POWER RACE-FREE STATE ASSIGNMENT OF AN ASYNGHRONOUS AUTOMATON

    Directory of Open Access Journals (Sweden)

    Yu. V. Pottosin

    2015-01-01

    Full Text Available The problem of a race free state assignment of an asynchronous automaton is considered. A method for the state assignment is suggested that provides the minimization of the number and theswitching activity of the memory elements along with the elimination of the critical races betweenthem.

  17. Simulating physics with cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    Vichniac, G Y

    1984-01-01

    Cellular automata are dynamical systems where space, time, and variables are discrete. They are shown on two-dimensional examples to be capable of non-numerical simulations of physics. They are useful for faithful parallel processing of lattice models. At another level, they exhibit behaviours and illustrate concepts that are unmistakably physical, such as non-ergodicity and order parameters, frustration, relaxation to chaos through period doublings, a conspicuous arrow of time in reversible microscopic dynamics, causality and light-cone, and non-separability. In general, they constitute exactly computable models for complex phenomena and large-scale correlations that result from very simple short-range interactions. The author studies their space, time, and intrinsic symmetries and the corresponding conservation laws, with an emphasis on the conservation of information obeyed by reversible cellular automata. 60 references.

  18. Three-dimensional simulations of cellular non-premixed jet flames

    Energy Technology Data Exchange (ETDEWEB)

    Valaer, A.L.; Frouzakis, C.E.; Boulouchos, K. [Aerothermochemistry and Combustion System Laboratory, Swiss Federal Institute of Technology, CH-8092 Zurich (Switzerland); Papas, P. [Division of Engineering, Colorado School of Mines, Golden, CO 80401 (United States); Tomboulides, A.G. [Department of Engineering and Management of Energy Resources, University of Western Macedonia, 50100 Kozani (Greece)

    2010-04-15

    The formation, dynamics and structure of cellular flames in circular non-premixed jets are examined with three-dimensional numerical simulations incorporating detailed descriptions of chemistry and transport. Similar to past experiments reported in the literature, CO{sub 2}-diluted hydrogen in diluted or pure oxygen co-flowing streams in the proximity of the extinction limit are considered. As in the experiments, several preferred cellular states are found to co-exist with the particular state realized depending on initial conditions as well as on the jet characteristics. The simulations provide additionally the temporal transitions to different stationary or rotating cellular flames, their detailed structure, and the dependence of the scaling of the realized number of cells with the vorticity thickness. (author)

  19. Toward an automaton Constraint for Local Search

    Directory of Open Access Journals (Sweden)

    Jun He

    2009-10-01

    Full Text Available We explore the idea of using finite automata to implement new constraints for local search (this is already a successful technique in constraint-based global search. We show how it is possible to maintain incrementally the violations of a constraint and its decision variables from an automaton that describes a ground checker for that constraint. We establish the practicality of our approach idea on real-life personnel rostering problems, and show that it is competitive with the approach of [Pralong, 2007].

  20. Modelling for near-surface interaction of lithium ceramics and sweep-gas by use of cellular automation

    International Nuclear Information System (INIS)

    Shimura, K.; Terai, T.; Yamawaki, M.; Yamaguchi, K.

    2003-01-01

    Tritium release from the lithium ceramics as a fusion reactor breeder material is strongly affected by the composition of the sweep-gas as result of its influences with the material's surface. The typical surface processes which play important roles are adsorption, desorption and interaction between vacancy site and the constituents of the sweep-gas. Among a large number of studies and models, yet it seems to be difficult to model the overall behaviour of those processes due to its complex time-transient nature. In the present work the coarse grained atomic simulation based on the Cellular Automaton (CA) is used to model the dynamics of near-surface interaction between Li 2 O surface and sweep-gas that is consisting of a noble gas, hydrogen gas and water vapour. (author)

  1. Mesoscale modeling and simulation of microstructure evolution during dynamic recrystallization of a Ni-based superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fei [University of Nottingham, Department of Mechanical, Materials and Manufacturing Engineering, Nottingham (United Kingdom); Shanghai Jiao Tong University, Institute of Forming Technology and Equipment, Shanghai (China); Cui, Zhenshan [Shanghai Jiao Tong University, Institute of Forming Technology and Equipment, Shanghai (China); Ou, Hengan [University of Nottingham, Department of Mechanical, Materials and Manufacturing Engineering, Nottingham (United Kingdom); Long, Hui [University of Sheffield, Department of Mechanical Engineering, Sheffield (United Kingdom)

    2016-10-15

    Microstructural evolution and plastic flow characteristics of a Ni-based superalloy were investigated using a simulative model that couples the basic metallurgical principle of dynamic recrystallization (DRX) with the two-dimensional (2D) cellular automaton (CA). Variation of dislocation density with local strain of deformation is considered for accurate determination of the microstructural evolution during DRX. The grain topography, the grain size and the recrystallized fraction can be well predicted by using the developed CA model, which enables to the establishment of the relationship between the flow stress, dislocation density, recrystallized fraction volume, recrystallized grain size and the thermomechanical parameters. (orig.)

  2. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    An extensive computer simulation using empirical pseudopotential method ... Two- and three-dimensional models for analysis of optical absorption in ... Study on growth factors of intermetallic layer within hot-dipped 25%Al-Zn alloy coating on steel ... Cellular automaton simulation of microstructure evolution during austenite ...

  3. Cellular automata in image processing and geometry

    CERN Document Server

    Adamatzky, Andrew; Sun, Xianfang

    2014-01-01

    The book presents findings, views and ideas on what exact problems of image processing, pattern recognition and generation can be efficiently solved by cellular automata architectures. This volume provides a convenient collection in this area, in which publications are otherwise widely scattered throughout the literature. The topics covered include image compression and resizing; skeletonization, erosion and dilation; convex hull computation, edge detection and segmentation; forgery detection and content based retrieval; and pattern generation. The book advances the theory of image processing, pattern recognition and generation as well as the design of efficient algorithms and hardware for parallel image processing and analysis. It is aimed at computer scientists, software programmers, electronic engineers, mathematicians and physicists, and at everyone who studies or develops cellular automaton algorithms and tools for image processing and analysis, or develops novel architectures and implementations of mass...

  4. High performance cellular level agent-based simulation with FLAME for the GPU.

    Science.gov (United States)

    Richmond, Paul; Walker, Dawn; Coakley, Simon; Romano, Daniela

    2010-05-01

    Driven by the availability of experimental data and ability to simulate a biological scale which is of immediate interest, the cellular scale is fast emerging as an ideal candidate for middle-out modelling. As with 'bottom-up' simulation approaches, cellular level simulations demand a high degree of computational power, which in large-scale simulations can only be achieved through parallel computing. The flexible large-scale agent modelling environment (FLAME) is a template driven framework for agent-based modelling (ABM) on parallel architectures ideally suited to the simulation of cellular systems. It is available for both high performance computing clusters (www.flame.ac.uk) and GPU hardware (www.flamegpu.com) and uses a formal specification technique that acts as a universal modelling format. This not only creates an abstraction from the underlying hardware architectures, but avoids the steep learning curve associated with programming them. In benchmarking tests and simulations of advanced cellular systems, FLAME GPU has reported massive improvement in performance over more traditional ABM frameworks. This allows the time spent in the development and testing stages of modelling to be drastically reduced and creates the possibility of real-time visualisation for simple visual face-validation.

  5. The nature of turbulence in a triangular lattice gas automaton

    Science.gov (United States)

    Duong-Van, Minh; Feit, M. D.; Keller, P.; Pound, M.

    1986-12-01

    Power spectra calculated from the coarse-graining of a simple lattice gas automaton, and those of time averaging other stochastic times series that we have investigated, have exponents in the range -1.6 to -2, consistent with observation of fully developed turbulence. This power spectrum is a natural consequence of coarse-graining; the exponent -2 represents the continuum limit.

  6. Flows around a moving flat plate simulated by the method of cellular automata. Seru outoman ho ni yoru ido heiban mawari no nagare

    Energy Technology Data Exchange (ETDEWEB)

    Tsutahara, M; Tomiyama, A; Kimura, T; Murata, H [Kobe University, Kobe (Japan). Faculty of Engineering

    1993-08-25

    In order to analyze the field of flow containing a moving boundary by the method of cellular automaton, the method of giving the boundary conditions in the case where a wall is moving at a constant velocity in the normal direction was examined. This method is used to simulate the movement of continuous fluid by statistically treating the movement of many discrete particles which repeat translation and collision. The collision law of particles at grid points is formulated so as to conserve mass(number of particles) and momentum for the purpose of satisfying the governing equation of flow. The object is the flow in the case where a flat plate moves in the normal direction inside the fluid enclosed by rectangular walls and the plate was assumed that it is first in a standing condition, then starts to move from left to right at a speed of V and stops in front of the right wall. Three boundary conditions, surrounding wall, plate in the standing condition and moving plate, were considered. Flow rates were calculated concerning the translation and collision and each divided mean-field-approximation region(space having a magnitude of capable of averaging operation of particles). Effectiveness of proposed boundary conditions was confirmed by a visualization experiment. 3 refs., 14 figs.

  7. The linearity of quantum mechanics from the perspective of Hamiltonian cellular automata

    International Nuclear Information System (INIS)

    Enrico Fermi, Università di Pisa, Largo Pontecorvo 3, I-56127 Pisa (Italy))" data-affiliation=" (Dipartimento di Fisica Enrico Fermi, Università di Pisa, Largo Pontecorvo 3, I-56127 Pisa (Italy))" >Elze, Hans-Thomas

    2014-01-01

    We discuss the action principle and resulting Hamiltonian equations of motion for a class of integer-valued cellular automata introduced recently [1]. Employing sampling theory, these deterministic finite-difference equations are mapped reversibly on continuum equations describing a set of bandwidth limited harmonic oscillators. They represent the Schrödinger equation. However, modifications reflecting the bandwidth limit are incorporated, i.e., the presence of a time (or length) scale. When this discreteness scale is taken to zero, the usual results are obtained. Thus, the linearity of quantum mechanics can be traced to the postulated action principle of such cellular automata and its conservation laws to discrete ones. The cellular automaton conservation laws are in one-to-one correspondence with those of the related quantum mechanical model, while admissible symmetries are not.

  8. A Cellular Automata-Based Simulation Tool for Real Fire Accident Prevention

    Directory of Open Access Journals (Sweden)

    Jacek M. Czerniak

    2018-01-01

    Full Text Available Many serious real-life problems could be simulated using cellular automata theory. There were a lot of fires in public places which kill many people. Proposed method, called Cellular Automata Evaluation (CAEva in short, is using cellular automata theory and could be used for checking buildings conditions for fire accident. The tests performed on real accident showed that an appropriately configured program allows obtaining a realistic simulation of human evacuation. The authors analyze some real accidents and proved that CAEva method appears as a very promising solution, especially in the cases of building renovations or temporary unavailability of escape routes.

  9. Modélisation tridimensionnelle Automate Cellulaire - Éléments Finis (CAFE) pour la simulation du développement des structures de grains dans les procédés de soudage GTAW / GMAW

    OpenAIRE

    Chen , Shijia

    2014-01-01

    Grain structure formation during fusion welding processes has a significant impact on the mechanical strength of the joint. Defects such as hot cracking are also linked to the crystallographic texture formed during the solidification step. Direct simulation of three-dimensional (3D) grain structure at industrial scale for welding processes is rarely modeled. In this work, a 3D coupled Cellular Automaton (CA) – Finite Element (FE) model is proposed to predict the grain structure formation duri...

  10. Simulation of root forms using cellular automata model

    International Nuclear Information System (INIS)

    Winarno, Nanang; Prima, Eka Cahya; Afifah, Ratih Mega Ayu

    2016-01-01

    This research aims to produce a simulation program for root forms using cellular automata model. Stephen Wolfram in his book entitled “A New Kind of Science” discusses the formation rules based on the statistical analysis. In accordance with Stephen Wolfram’s investigation, the research will develop a basic idea of computer program using Delphi 7 programming language. To best of our knowledge, there is no previous research developing a simulation describing root forms using the cellular automata model compared to the natural root form with the presence of stone addition as the disturbance. The result shows that (1) the simulation used four rules comparing results of the program towards the natural photographs and each rule had shown different root forms; (2) the stone disturbances prevent the root growth and the multiplication of root forms had been successfully modeled. Therefore, this research had added some stones, which have size of 120 cells placed randomly in the soil. Like in nature, stones cannot be penetrated by plant roots. The result showed that it is very likely to further develop the program of simulating root forms by 50 variations

  11. Simulation of root forms using cellular automata model

    Energy Technology Data Exchange (ETDEWEB)

    Winarno, Nanang, E-mail: nanang-winarno@upi.edu; Prima, Eka Cahya [International Program on Science Education, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudi no 229, Bandung40154 (Indonesia); Afifah, Ratih Mega Ayu [Department of Physics Education, Post Graduate School, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudi no 229, Bandung40154 (Indonesia)

    2016-02-08

    This research aims to produce a simulation program for root forms using cellular automata model. Stephen Wolfram in his book entitled “A New Kind of Science” discusses the formation rules based on the statistical analysis. In accordance with Stephen Wolfram’s investigation, the research will develop a basic idea of computer program using Delphi 7 programming language. To best of our knowledge, there is no previous research developing a simulation describing root forms using the cellular automata model compared to the natural root form with the presence of stone addition as the disturbance. The result shows that (1) the simulation used four rules comparing results of the program towards the natural photographs and each rule had shown different root forms; (2) the stone disturbances prevent the root growth and the multiplication of root forms had been successfully modeled. Therefore, this research had added some stones, which have size of 120 cells placed randomly in the soil. Like in nature, stones cannot be penetrated by plant roots. The result showed that it is very likely to further develop the program of simulating root forms by 50 variations.

  12. Simulation of dendritic growth of magnesium alloys with fluid flow

    Directory of Open Access Journals (Sweden)

    Meng-wu Wu

    2017-11-01

    Full Text Available Fluid flow has a significant impact on the microstructure evolution of alloys during solidification. Based on the previous work relating simulation of the dendritic growth of magnesium alloys with hcp (hexagonal close-packed structure, an extension was made to the formerly established CA (cellular automaton model with the purpose of studying the effect of fluid flow on the dendritic growth of magnesium alloys. The modified projection method was used to solve the transport equations of flow field. By coupling the flow field with the solute field, simulation results of equiaxed and columnar dendritic growth of magnesium alloys with fluid flow were achieved. The simulated results were quantitatively compared with those without fluid flow. Moreover, a comparison was also made between the present work and previous works conducted by others. It can be concluded that a deep understanding of the dendritic growth of magnesium alloys with fluid flow can be obtained by applying the present numerical model.

  13. Développement d'une approche couplée Automates Cellulaires – Eléments Finis pour la modélisation du développement des structures de grains en soudage TIG A coupled Cellular Automaton – Finite Element approach for the modelling of grain structure development in TIG welding

    Directory of Open Access Journals (Sweden)

    Chen Shijia

    2013-11-01

    Full Text Available Dans le domaine du soudage, les propriétés finales du cordon sont fortement liées à la structure de grains développée au cours des procédés de fusion / resolidification. La maîtrise des propriétés de l'assemblage final passe ainsi par une amélioration de la connaissance de sa structure de ce domaine. Dans cet objectif, un modèle couplé Automates Cellulaires – Eléments Finis est proposé pour simuler le développement, en volume, de cette structure, dans le cadre du soudage TIG. Ce modèle est appliqué au soudage d'acier Duplex 2202 et l'évolution de la structure de grains selon les paramètres procédés est discutée. In the welding area, the final properties of the weld bead are mainly induced by the grain structure developed during the melting and solidification steps. The mastery of the properties of the joining will be achieved with a better knowledge of the developed grain structure. A 3D coupled Cellular Automaton – Finite Element model is proposed in order to simulate the grains development in TIG process. This model is applied to the welding of a duplex stainless steel grade. The grain structure evolution is discussed for the various process parameters.

  14. Simulation of microstructural evolution in directional solidification of Ti-45at.%Al alloy using cellular automaton method

    Directory of Open Access Journals (Sweden)

    Wang Kuangfei

    2010-02-01

    Full Text Available The microstructural evolution of Ti-45 at.%Al alloy during directional solidification was simulated by applying a solute diffusion controlled solidification model. The obtained results have shown that under high thermal gradients the stable primary spacing can be adjusted via branching or competitive growth. For dendritic structures formed under a high thermal gradient, the secondary dendrite arms are developed not very well in many cases due to the branching mechanism under a constrained dendritic growth condition. Furthermore, it has been observed that, with increasing pulling velocity, there exists a cell/dendrite transition region consisting of cells and dendrites, which varies with the thermal gradient in a contradicting way, i.e. increase of the thermal gradient leading to the decrease of the range of the transition region. The simulations agree reasonably well with experiment results.

  15. Cellular Automata Based Modeling for Evaluating Different Bus Stop Designs in China

    Directory of Open Access Journals (Sweden)

    Haoyang Ding

    2015-01-01

    Full Text Available A cellular automaton model is proposed to simulate mixed traffic flow composed of motor vehicles and bicycles near bus stops. Three typical types of bus stops which are common in China are considered in the model, including two types of curbside bus stops and one type of bus bay stops. Passenger transport capacity of three types of bus stops, which is applied to evaluate the bus stop design, is calculated based on the corresponding traffic flow rate. According to the simulation results, the flow rates of both motor vehicles and bicycles exhibit phase transition from free flow to the saturation one at the critical point. The results also show that the larger the interaction between motor vehicle and bicycle flow is near curbside bus stops, the more the value of saturated flows drops. Curbside bus stops are more suitable when the conflicts between two flows are small and the inflow rate of motor vehicles is low. On the contrary, bus bay stops should be applied due to their ability to reduce traffic conflicts. Findings of this study can provide useful suggestions on bus stop selection considering different inflow rate of motor vehicles and bicycles simultaneously.

  16. Hybrid cellular automaton modeling of nutrient modulated cell growth in tissue engineering constructs.

    Science.gov (United States)

    Chung, C A; Lin, Tze-Hung; Chen, Shih-Di; Huang, Hsing-I

    2010-01-21

    Mathematic models help interpret experimental results and accelerate tissue engineering developments. We develop in this paper a hybrid cellular automata model that combines the differential nutrient transport equation to investigate the nutrient limited cell construct development for cartilage tissue engineering. Individual cell behaviors of migration, contact inhibition and cell collision, coupled with the cell proliferation regulated by oxygen concentration were carefully studied. Simplified two-dimensional simulations were performed. Using this model, we investigated the influence of cell migration speed on the overall cell growth within in vitro cell scaffolds. It was found that intense cell motility can enhance initial cell growth rates. However, since cell growth is also significantly modulated by the nutrient contents, intense cell motility with conventional uniform cell seeding method may lead to declined cell growth in the final time because concentrated cell population has been growing around the scaffold periphery to block the nutrient transport from outside culture media. Therefore, homogeneous cell seeding may not be a good way of gaining large and uniform cell densities for the final results. We then compared cell growth in scaffolds with various seeding modes, and proposed a seeding mode with cells initially residing in the middle area of the scaffold that may efficiently reduce the nutrient blockage and result in a better cell amount and uniform cell distribution for tissue engineering construct developments.

  17. A Compact Synchronous Cellular Model of Nonlinear Calcium Dynamics: Simulation and FPGA Synthesis Results.

    Science.gov (United States)

    Soleimani, Hamid; Drakakis, Emmanuel M

    2017-06-01

    Recent studies have demonstrated that calcium is a widespread intracellular ion that controls a wide range of temporal dynamics in the mammalian body. The simulation and validation of such studies using experimental data would benefit from a fast large scale simulation and modelling tool. This paper presents a compact and fully reconfigurable cellular calcium model capable of mimicking Hopf bifurcation phenomenon and various nonlinear responses of the biological calcium dynamics. The proposed cellular model is synthesized on a digital platform for a single unit and a network model. Hardware synthesis, physical implementation on FPGA, and theoretical analysis confirm that the proposed cellular model can mimic the biological calcium behaviors with considerably low hardware overhead. The approach has the potential to speed up large-scale simulations of slow intracellular dynamics by sharing more cellular units in real-time. To this end, various networks constructed by pipelining 10 k to 40 k cellular calcium units are compared with an equivalent simulation run on a standard PC workstation. Results show that the cellular hardware model is, on average, 83 times faster than the CPU version.

  18. Continuous limit of a crowd motion and herding model: Analysis and numerical simulations

    KAUST Repository

    Pietschmann, Jan-Frederik; Markowich, Peter Alexander; Burger, Martin

    2011-01-01

    In this paper we study the continuum limit of a cellular automaton model used for simulating human crowds with herding behaviour. We derive a system of non-linear partial differential equations resembling the Keller-Segel model for chemotaxis, however with a non-monotone interaction. The latter has interesting consequences on the behaviour of the model's solutions, which we highlight in its analysis. In particular we study the possibility of stationary states, the formation of clusters and explore their connection to congestion. We also introduce an efficient numerical simulation approach based on an appropriate hybrid discontinuous Galerkin method, which in particular allows flexible treatment of complicated geometries. Extensive numerical studies also provide a better understanding of the strengths and shortcomings of the herding model, in particular we examine trapping effects of crowds behind nonconvex obstacles. © American Institute of Mathematical Sciences.

  19. Continuous limit of a crowd motion and herding model: Analysis and numerical simulations

    KAUST Repository

    Pietschmann, Jan-Frederik

    2011-11-01

    In this paper we study the continuum limit of a cellular automaton model used for simulating human crowds with herding behaviour. We derive a system of non-linear partial differential equations resembling the Keller-Segel model for chemotaxis, however with a non-monotone interaction. The latter has interesting consequences on the behaviour of the model\\'s solutions, which we highlight in its analysis. In particular we study the possibility of stationary states, the formation of clusters and explore their connection to congestion. We also introduce an efficient numerical simulation approach based on an appropriate hybrid discontinuous Galerkin method, which in particular allows flexible treatment of complicated geometries. Extensive numerical studies also provide a better understanding of the strengths and shortcomings of the herding model, in particular we examine trapping effects of crowds behind nonconvex obstacles. © American Institute of Mathematical Sciences.

  20. On the effect of memory in a quantum prisoner's dilemma cellular automaton

    Science.gov (United States)

    Alonso-Sanz, Ramón; Revuelta, Fabio

    2018-03-01

    The disrupting effect of quantum memory on the dynamics of a spatial quantum formulation of the iterated prisoner's dilemma game with variable entangling is studied. The game is played within a cellular automata framework, i.e., with local and synchronous interactions. The main findings of this work refer to the shrinking effect of memory on the disruption induced by noise.

  1. The effect of cellular aging on the dynamics of spiral waves

    International Nuclear Information System (INIS)

    Deng Min-Yi; Chen Xi-Qiong; Tang Guo-Ning

    2014-01-01

    Cellular aging can result in deterioration of electrical coupling, the extension of the action potential duration, and lower excitability of the cell. Those factors are introduced into the Greenberg—Hastings cellular automaton model and the effects of the cellular aging on the dynamics of spiral waves are studied. The numerical results show that a 50% reduction of the coupling strength of aging cells has a little influence on spiral waves. If the coupling strength of aging cells equals zero, the ability for the medium to maintain spiral waves will be reduced by approximately 50% when the aging cell ratio increases from 0 to 0.5, where the reduction of cell excitability plays a major role in inducing disappearance of spiral waves. When the relevant parameters are properly chosen, the cellular aging can lead to the meandering of spiral waves, the emergence of the binary spiral waves, and even the disappearance of spiral waves via the stopping rotation or shrinkage of wave. Physical mechanisms of the above phenomena are analyzed briefly. (general)

  2. Study of Drying Shrinkage Cracking by Lattice Gas Automaton and Environmental Scanning Electron Microscope

    NARCIS (Netherlands)

    Van Mier, J.G.M.; Jankovic, D.

    2005-01-01

    Numerical modeling of moisture flow, drying shrinkage and crack phenomena in cement microstructure, by coupling a Lattice Gas Automaton and a Lattice Fracture Model, highlighted the importance of a shrinkage coefficient (?sh) as the most significant parameter for achieving realistic numerical

  3. Fulltext PDF

    Indian Academy of Sciences (India)

    Unknown

    Effect of stress ratio and frequency on fatigue crack growth rate of 2618 aluminium alloy silicon carbide metal matrix composite. 169 ... Characterization of ancient Indian iron and entrapped slag inclu- ... Cellular automaton simulation of microstructure evolution .... High temperature flow behaviour of SiC reinforced lithium.

  4. Evolution of Cellular Automata toward a LIFE-Like Rule Guided by 1/ƒ Noise

    Science.gov (United States)

    Ninagawa, Shigeru

    There is evidence in favor of a relationship between the presence of 1/ƒ noise and computational universality in cellular automata. To confirm the relationship, we search for two-dimensional cellular automata with a 1/ƒ power spectrum by means of genetic algorithms. The power spectrum is calculated from the evolution of the state of the cell, starting from a random initial configuration. The fitness is estimated by the power spectrum with consideration of the spectral similarity to the 1/ƒ spectrum. The result shows that the rule with the highest fitness over the most runs exhibits a 1/ƒ type spectrum and its transition function and behavior are quite similar to those of the Game of Life, which is known to be a computationally universal cellular automaton. These results support the relationship between the presence of 1/ƒ noise and computational universality.

  5. A hybrid parallel framework for the cellular Potts model simulations

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yi [Los Alamos National Laboratory; He, Kejing [SOUTH CHINA UNIV; Dong, Shoubin [SOUTH CHINA UNIV

    2009-01-01

    The Cellular Potts Model (CPM) has been widely used for biological simulations. However, most current implementations are either sequential or approximated, which can't be used for large scale complex 3D simulation. In this paper we present a hybrid parallel framework for CPM simulations. The time-consuming POE solving, cell division, and cell reaction operation are distributed to clusters using the Message Passing Interface (MPI). The Monte Carlo lattice update is parallelized on shared-memory SMP system using OpenMP. Because the Monte Carlo lattice update is much faster than the POE solving and SMP systems are more and more common, this hybrid approach achieves good performance and high accuracy at the same time. Based on the parallel Cellular Potts Model, we studied the avascular tumor growth using a multiscale model. The application and performance analysis show that the hybrid parallel framework is quite efficient. The hybrid parallel CPM can be used for the large scale simulation ({approx}10{sup 8} sites) of complex collective behavior of numerous cells ({approx}10{sup 6}).

  6. Treatment Analysis in a Cancer Stem Cell Context Using a Tumor Growth Model Based on Cellular Automata.

    Science.gov (United States)

    Monteagudo, Ángel; Santos, José

    2015-01-01

    Cancer can be viewed as an emergent behavior in terms of complex system theory and artificial life, Cellular Automata (CA) being the tool most used for studying and characterizing the emergent behavior. Different approaches with CA models were used to model cancer growth. The use of the abstract model of acquired cancer hallmarks permits the direct modeling at cellular level, where a cellular automaton defines the mitotic and apoptotic behavior of cells, and allows for an analysis of different dynamics of the cellular system depending on the presence of the different hallmarks. A CA model based on the presence of hallmarks in the cells, which includes a simulation of the behavior of Cancer Stem Cells (CSC) and their implications for the resultant growth behavior of the multicellular system, was employed. This modeling of cancer growth, in the avascular phase, was employed to analyze the effect of cancer treatments in a cancer stem cell context. The model clearly explains why, after treatment against non-stem cancer cells, the regrowth capability of CSCs generates a faster regrowth of tumor behavior, and also shows that a continuous low-intensity treatment does not favor CSC proliferation and differentiation, thereby allowing an unproblematic control of future tumor regrowth. The analysis performed indicates that, contrary to the current attempts at CSC control, trying to make CSC proliferation more difficult is an important point to consider, especially in the immediate period after a standard treatment for controlling non-stem cancer cell proliferation.

  7. Digitally programmable microfluidic automaton for multiscale combinatorial mixing and sample processing†

    Science.gov (United States)

    Jensen, Erik C.; Stockton, Amanda M.; Chiesl, Thomas N.; Kim, Jungkyu; Bera, Abhisek; Mathies, Richard A.

    2013-01-01

    A digitally programmable microfluidic Automaton consisting of a 2-dimensional array of pneumatically actuated microvalves is programmed to perform new multiscale mixing and sample processing operations. Large (µL-scale) volume processing operations are enabled by precise metering of multiple reagents within individual nL-scale valves followed by serial repetitive transfer to programmed locations in the array. A novel process exploiting new combining valve concepts is developed for continuous rapid and complete mixing of reagents in less than 800 ms. Mixing, transfer, storage, and rinsing operations are implemented combinatorially to achieve complex assay automation protocols. The practical utility of this technology is demonstrated by performing automated serial dilution for quantitative analysis as well as the first demonstration of on-chip fluorescent derivatization of biomarker targets (carboxylic acids) for microchip capillary electrophoresis on the Mars Organic Analyzer. A language is developed to describe how unit operations are combined to form a microfluidic program. Finally, this technology is used to develop a novel microfluidic 6-sample processor for combinatorial mixing of large sets (>26 unique combinations) of reagents. The digitally programmable microfluidic Automaton is a versatile programmable sample processor for a wide range of process volumes, for multiple samples, and for different types of analyses. PMID:23172232

  8. Algorithm for repairing the damaged images of grain structures obtained from the cellular automata and measurement of grain size

    Science.gov (United States)

    Ramírez-López, A.; Romero-Romo, M. A.; Muñoz-Negron, D.; López-Ramírez, S.; Escarela-Pérez, R.; Duran-Valencia, C.

    2012-10-01

    Computational models are developed to create grain structures using mathematical algorithms based on the chaos theory such as cellular automaton, geometrical models, fractals, and stochastic methods. Because of the chaotic nature of grain structures, some of the most popular routines are based on the Monte Carlo method, statistical distributions, and random walk methods, which can be easily programmed and included in nested loops. Nevertheless, grain structures are not well defined as the results of computational errors and numerical inconsistencies on mathematical methods. Due to the finite definition of numbers or the numerical restrictions during the simulation of solidification, damaged images appear on the screen. These images must be repaired to obtain a good measurement of grain geometrical properties. Some mathematical algorithms were developed to repair, measure, and characterize grain structures obtained from cellular automata in the present work. An appropriate measurement of grain size and the corrected identification of interfaces and length are very important topics in materials science because they are the representation and validation of mathematical models with real samples. As a result, the developed algorithms are tested and proved to be appropriate and efficient to eliminate the errors and characterize the grain structures.

  9. Simulation Modeling by Classification of Problems: A Case of Cellular Manufacturing

    International Nuclear Information System (INIS)

    Afiqah, K N; Mahayuddin, Z R

    2016-01-01

    Cellular manufacturing provides good solution approach to manufacturing area by applying Group Technology concept. The evolution of cellular manufacturing can enhance performance of the cell and to increase the quality of the product manufactured but it triggers other problem. Generally, this paper highlights factors and problems which emerge commonly in cellular manufacturing. The aim of the research is to develop a thorough understanding of common problems in cellular manufacturing. A part from that, in order to find a solution to the problems exist using simulation technique, this classification framework is very useful to be adapted during model building. Biology evolution tool was used in the research in order to classify the problems emerge. The result reveals 22 problems and 25 factors using cladistic technique. In this research, the expected result is the cladogram established based on the problems in cellular manufacturing gathered. (paper)

  10. Stochastic cellular automata model and Monte Carlo simulations of CD4+ T cell dynamics with a proposed alternative leukapheresis treatment for HIV/AIDS.

    Science.gov (United States)

    Precharattana, Monamorn; Nokkeaw, Arthorn; Triampo, Wannapong; Triampo, Darapond; Lenbury, Yongwimon

    2011-07-01

    Acquired Immunodeficiency Syndrome (AIDS) is responsible for millions of deaths worldwide. To date, many drug treatment regimens have been applied to AIDS patients but none has resulted in a successful cure. This is mainly due to the fact that free HIV particles are frequently in mutation, and infected CD4(+) T cells normally reside in the lymphoid tissue where they cannot (so far) be eradicated. We present a stochastic cellular automaton (CA) model to computationally study what could be an alternative treatment, namely Leukapheresis (LCAP), to remove HIV infected leukocytes in the lymphoid tissue. We base our investigations on Monte Carlo computer simulations. Our major objective is to investigate how the number of infected CD4(+) T cells changes in response to LCAP during the short-time (weeks) and long-time (years) scales of HIV/AIDS progression in an infected individual. To achieve our goal, we analyze the time evolution of the CD4(+) T cell population in the lymphoid tissue (i.e., the lymph node) for HIV dynamics in treatment situations with various starting times and frequencies and under a no treatment condition. Our findings suggest that the effectiveness of the treatment depends mainly on the treatment starting time and the frequency of the LCAP. Other factors (e.g., the removal proportion, the treatment duration, and the state of removed cells) that likely influence disease progression are subjects for further investigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Two Phase Flow Simulation Using Cellular Automata

    International Nuclear Information System (INIS)

    Marcel, C.P.

    2002-01-01

    The classical mathematical treatment of two-phase flows is based on the average of the conservation equations for each phase.In this work, a complementary approach to the modeling of these systems based on statistical population balances of aut omata sets is presented.Automata are entities defined by mathematical states that change following iterative rules representing interactions with the neighborhood.A model of automata for two-phase flow simulation is presented.This model consists of fie lds of virtual spheres that change their volumes and move around a certain environment.The model is more general than the classical cellular automata in two respects: the grid of cellular automata is dismissed in favor of a trajectory generator, and the rules of interaction involve parameters representing the actual physical interactions between phases.Automata simulation was used to study unsolved two-phase flow problems involving high heat flux rates. One system described in this work consists of a vertical channel with saturated water at normal pressure heated from the lower surface.The heater causes water to boil and starts the bubble production.We used cellular automata to describe two-phase flows and the interaction with the heater.General rule s for such cellular automata representing bubbles moving in stagnant liquid were used, with special attention to correct modeling of different mechanisms of heat transfer.The results of the model were compared to previous experiments and correlations finding good agreement.One of the most important findings is the confirmation of Kutateladze's idea about a close relation between the start of critical heat flux and a change in the flow's topology.This was analyzed using a control volume located in the upper surface of the heater.A strong decrease in the interfacial surface just before the CHF start was encountered.The automata describe quite well some characteristic parameters such as the shape of the local void fraction in the

  12. Stair evacuation simulation based on cellular automata considering evacuees’ walk preferences

    International Nuclear Information System (INIS)

    Ding Ning; Luh, Peter B.; Zhang Hui; Chen Tao

    2015-01-01

    As a physical model, the cellular automata (CA) model is widely used in many areas, such as stair evacuation. However, existing CA models do not consider evacuees’ walk preferences nor psychological status, and the structure of the basic model is unapplicable for the stair structure. This paper is to improve the stair evacuation simulation by addressing these issues, and a new cellular automata model is established. Several evacuees’ walk preference and how evacuee’s psychology influences their behaviors are introduced into this model. Evacuees’ speeds will be influenced by these features. To validate this simulation, two fire drills held in two high-rise buildings are video-recorded. It is found that the simulation results are similar to the fire drill results. The structure of this model is simple, and it is easy to further develop and utilize in different buildings with various kinds of occupants. (paper)

  13. Simulating Urban Growth Using a Random Forest-Cellular Automata (RF-CA Model

    Directory of Open Access Journals (Sweden)

    Courage Kamusoko

    2015-04-01

    Full Text Available Sustainable urban planning and management require reliable land change models, which can be used to improve decision making. The objective of this study was to test a random forest-cellular automata (RF-CA model, which combines random forest (RF and cellular automata (CA models. The Kappa simulation (KSimulation, figure of merit, and components of agreement and disagreement statistics were used to validate the RF-CA model. Furthermore, the RF-CA model was compared with support vector machine cellular automata (SVM-CA and logistic regression cellular automata (LR-CA models. Results show that the RF-CA model outperformed the SVM-CA and LR-CA models. The RF-CA model had a Kappa simulation (KSimulation accuracy of 0.51 (with a figure of merit statistic of 47%, while SVM-CA and LR-CA models had a KSimulation accuracy of 0.39 and −0.22 (with figure of merit statistics of 39% and 6%, respectively. Generally, the RF-CA model was relatively accurate at allocating “non-built-up to built-up” changes as reflected by the correct “non-built-up to built-up” components of agreement of 15%. The performance of the RF-CA model was attributed to the relatively accurate RF transition potential maps. Therefore, this study highlights the potential of the RF-CA model for simulating urban growth.

  14. Cellular automata models for diffusion of information and highway traffic flow

    Science.gov (United States)

    Fuks, Henryk

    In the first part of this work we study a family of deterministic models for highway traffic flow which generalize cellular automaton rule 184. This family is parameterized by the speed limit m and another parameter k that represents degree of 'anticipatory driving'. We compare two driving strategies with identical maximum throughput: 'conservative' driving with high speed limit and 'anticipatory' driving with low speed limit. Those two strategies are evaluated in terms of accident probability. We also discuss fundamental diagrams of generalized traffic rules and examine limitations of maximum achievable throughput. Possible modifications of the model are considered. For rule 184, we present exact calculations of the order parameter in a transition from the moving phase to the jammed phase using the method of preimage counting, and use this result to construct a solution to the density classification problem. In the second part we propose a probabilistic cellular automaton model for the spread of innovations, rumors, news, etc., in a social system. We start from simple deterministic models, for which exact expressions for the density of adopters are derived. For a more realistic model, based on probabilistic cellular automata, we study the influence of a range of interaction R on the shape of the adoption curve. When the probability of adoption is proportional to the local density of adopters, and individuals can drop the innovation with some probability p, the system exhibits a second order phase transition. Critical line separating regions of parameter space in which asymptotic density of adopters is positive from the region where it is equal to zero converges toward the mean-field line when the range of the interaction increases. In a region between R=1 critical line and the mean-field line asymptotic density of adopters depends on R, becoming zero if R is too small (smaller than some critical value). This result demonstrates the importance of connectivity in

  15. Treatment Analysis in a Cancer Stem Cell Context Using a Tumor Growth Model Based on Cellular Automata.

    Directory of Open Access Journals (Sweden)

    Ángel Monteagudo

    Full Text Available Cancer can be viewed as an emergent behavior in terms of complex system theory and artificial life, Cellular Automata (CA being the tool most used for studying and characterizing the emergent behavior. Different approaches with CA models were used to model cancer growth. The use of the abstract model of acquired cancer hallmarks permits the direct modeling at cellular level, where a cellular automaton defines the mitotic and apoptotic behavior of cells, and allows for an analysis of different dynamics of the cellular system depending on the presence of the different hallmarks. A CA model based on the presence of hallmarks in the cells, which includes a simulation of the behavior of Cancer Stem Cells (CSC and their implications for the resultant growth behavior of the multicellular system, was employed. This modeling of cancer growth, in the avascular phase, was employed to analyze the effect of cancer treatments in a cancer stem cell context. The model clearly explains why, after treatment against non-stem cancer cells, the regrowth capability of CSCs generates a faster regrowth of tumor behavior, and also shows that a continuous low-intensity treatment does not favor CSC proliferation and differentiation, thereby allowing an unproblematic control of future tumor regrowth. The analysis performed indicates that, contrary to the current attempts at CSC control, trying to make CSC proliferation more difficult is an important point to consider, especially in the immediate period after a standard treatment for controlling non-stem cancer cell proliferation.

  16. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    A spreading to non-spreading transition is seen in the system. A cellular automaton version of the coupled system maps the spreading to non-spreading transition to a transition from a probabilistic to a deterministic cellular automaton. The solitonic sector of the system shows spatiotemporal intermittency with soliton creation, ...

  17. An Automaton Analysis of the Learning of a Miniature System of Japanese. Psychology Series.

    Science.gov (United States)

    Wexler, Kenneth Norman

    The purpose of the study reported here was to do an automata-theoretical and experimental investigation of the learning of the syntax and semantics of a second natural language. The main thrust of the work was to ask what kind of automaton a person can become. Various kinds of automata were considered, predictions were made from them, and these…

  18. A coarse-grained model for the simulations of biomolecular interactions in cellular environments

    International Nuclear Information System (INIS)

    Xie, Zhong-Ru; Chen, Jiawen; Wu, Yinghao

    2014-01-01

    The interactions of bio-molecules constitute the key steps of cellular functions. However, in vivo binding properties differ significantly from their in vitro measurements due to the heterogeneity of cellular environments. Here we introduce a coarse-grained model based on rigid-body representation to study how factors such as cellular crowding and membrane confinement affect molecular binding. The macroscopic parameters such as the equilibrium constant and the kinetic rate constant are calibrated by adjusting the microscopic coefficients used in the numerical simulations. By changing these model parameters that are experimentally approachable, we are able to study the kinetic and thermodynamic properties of molecular binding, as well as the effects caused by specific cellular environments. We investigate the volumetric effects of crowded intracellular space on bio-molecular diffusion and diffusion-limited reactions. Furthermore, the binding constants of membrane proteins are currently difficult to measure. We provide quantitative estimations about how the binding of membrane proteins deviates from soluble proteins under different degrees of membrane confinements. The simulation results provide biological insights to the functions of membrane receptors on cell surfaces. Overall, our studies establish a connection between the details of molecular interactions and the heterogeneity of cellular environments

  19. Simulating tumor growth in confined heterogeneous environments

    International Nuclear Information System (INIS)

    Gevertz, Jana L; Torquato, Salvatore; Gillies, George T

    2008-01-01

    The holy grail of computational tumor modeling is to develop a simulation tool that can be utilized in the clinic to predict neoplastic progression and propose individualized optimal treatment strategies. In order to develop such a predictive model, one must account for many of the complex processes involved in tumor growth. One interaction that has not been incorporated into computational models of neoplastic progression is the impact that organ-imposed physical confinement and heterogeneity have on tumor growth. For this reason, we have taken a cellular automaton algorithm that was originally designed to simulate spherically symmetric tumor growth and generalized the algorithm to incorporate the effects of tissue shape and structure. We show that models that do not account for organ/tissue geometry and topology lead to false conclusions about tumor spread, shape and size. The impact that confinement has on tumor growth is more pronounced when a neoplasm is growing close to, versus far from, the confining boundary. Thus, any clinical simulation tool of cancer progression must not only consider the shape and structure of the organ in which a tumor is growing, but must also consider the location of the tumor within the organ if it is to accurately predict neoplastic growth dynamics

  20. Molecular dynamics simulation of ribosome jam

    KAUST Repository

    Matsumoto, Shigenori

    2011-09-01

    We propose a coarse-grained molecular dynamics model of ribosome molecules to study the dependence of translation process on environmental parameters. We found the model exhibits traffic jam property, which is consistent with an ASEP model. We estimated the influence of the temperature and concentration of molecules on the hopping probability used in the ASEP model. Our model can also treat environmental effects on the translation process that cannot be explained by such cellular automaton models. © 2010 Elsevier B.V. All rights reserved.

  1. Generic framework for mining cellular automata models on protein-folding simulations.

    Science.gov (United States)

    Diaz, N; Tischer, I

    2016-05-13

    Cellular automata model identification is an important way of building simplified simulation models. In this study, we describe a generic architectural framework to ease the development process of new metaheuristic-based algorithms for cellular automata model identification in protein-folding trajectories. Our framework was developed by a methodology based on design patterns that allow an improved experience for new algorithms development. The usefulness of the proposed framework is demonstrated by the implementation of four algorithms, able to obtain extremely precise cellular automata models of the protein-folding process with a protein contact map representation. Dynamic rules obtained by the proposed approach are discussed, and future use for the new tool is outlined.

  2. Strictly local one-dimensional topological quantum error correction with symmetry-constrained cellular automata

    Directory of Open Access Journals (Sweden)

    Nicolai Lang, Hans Peter Büchler

    2018-01-01

    Full Text Available Active quantum error correction on topological codes is one of the most promising routes to long-term qubit storage. In view of future applications, the scalability of the used decoding algorithms in physical implementations is crucial. In this work, we focus on the one-dimensional Majorana chain and construct a strictly local decoder based on a self-dual cellular automaton. We study numerically and analytically its performance and exploit these results to contrive a scalable decoder with exponentially growing decoherence times in the presence of noise. Our results pave the way for scalable and modular designs of actively corrected one-dimensional topological quantum memories.

  3. Self-organisation in Cellular Automata with Coalescent Particles: Qualitative and Quantitative Approaches

    Science.gov (United States)

    Hellouin de Menibus, Benjamin; Sablik, Mathieu

    2017-06-01

    This article introduces new tools to study self-organisation in a family of simple cellular automata which contain some particle-like objects with good collision properties (coalescence) in their time evolution. We draw an initial configuration at random according to some initial shift-ergodic measure, and use the limit measure to describe the asymptotic behaviour of the automata. We first take a qualitative approach, i.e. we obtain information on the limit measure(s). We prove that only particles moving in one particular direction can persist asymptotically. This provides some previously unknown information on the limit measures of various deterministic and probabilistic cellular automata: 3 and 4-cyclic cellular automata [introduced by Fisch (J Theor Probab 3(2):311-338, 1990; Phys D 45(1-3):19-25, 1990)], one-sided captive cellular automata [introduced by Theyssier (Captive Cellular Automata, 2004)], the majority-traffic cellular automaton, a self stabilisation process towards a discrete line [introduced by Regnault and Rémila (in: Mathematical Foundations of Computer Science 2015—40th International Symposium, MFCS 2015, Milan, Italy, Proceedings, Part I, 2015)]. In a second time we restrict our study to a subclass, the gliders cellular automata. For this class we show quantitative results, consisting in the asymptotic law of some parameters: the entry times [generalising K ůrka et al. (in: Proceedings of AUTOMATA, 2011)], the density of particles and the rate of convergence to the limit measure.

  4. Research on the comparison of extension mechanism of cellular automaton based on hexagon grid and rectangular grid

    Science.gov (United States)

    Zhai, Xiaofang; Zhu, Xinyan; Xiao, Zhifeng; Weng, Jie

    2009-10-01

    Historically, cellular automata (CA) is a discrete dynamical mathematical structure defined on spatial grid. Research on cellular automata system (CAS) has focused on rule sets and initial condition and has not discussed its adjacency. Thus, the main focus of our study is the effect of adjacency on CA behavior. This paper is to compare rectangular grids with hexagonal grids on their characteristics, strengths and weaknesses. They have great influence on modeling effects and other applications including the role of nearest neighborhood in experimental design. Our researches present that rectangular and hexagonal grids have different characteristics. They are adapted to distinct aspects, and the regular rectangular or square grid is used more often than the hexagonal grid. But their relative merits have not been widely discussed. The rectangular grid is generally preferred because of its symmetry, especially in orthogonal co-ordinate system and the frequent use of raster from Geographic Information System (GIS). However, in terms of complex terrain, uncertain and multidirectional region, we have preferred hexagonal grids and methods to facilitate and simplify the problem. Hexagonal grids can overcome directional warp and have some unique characteristics. For example, hexagonal grids have a simpler and more symmetric nearest neighborhood, which avoids the ambiguities of the rectangular grids. Movement paths or connectivity, the most compact arrangement of pixels, make hexagonal appear great dominance in the process of modeling and analysis. The selection of an appropriate grid should be based on the requirements and objectives of the application. We use rectangular and hexagonal grids respectively for developing city model. At the same time we make use of remote sensing images and acquire 2002 and 2005 land state of Wuhan. On the base of city land state in 2002, we make use of CA to simulate reasonable form of city in 2005. Hereby, these results provide a proof of

  5. Cellular automata and integrodifferential equation models for cell renewal in mosaic tissues

    Science.gov (United States)

    Bloomfield, J. M.; Sherratt, J. A.; Painter, K. J.; Landini, G.

    2010-01-01

    Mosaic tissues are composed of two or more genetically distinct cell types. They occur naturally, and are also a useful experimental method for exploring tissue growth and maintenance. By marking the different cell types, one can study the patterns formed by proliferation, renewal and migration. Here, we present mathematical modelling suggesting that small changes in the type of interaction that cells have with their local cellular environment can lead to very different outcomes for the composition of mosaics. In cell renewal, proliferation of each cell type may depend linearly or nonlinearly on the local proportion of cells of that type, and these two possibilities produce very different patterns. We study two variations of a cellular automaton model based on simple rules for renewal. We then propose an integrodifferential equation model, and again consider two different forms of cellular interaction. The results of the continuous and cellular automata models are qualitatively the same, and we observe that changes in local environment interaction affect the dynamics for both. Furthermore, we demonstrate that the models reproduce some of the patterns seen in actual mosaic tissues. In particular, our results suggest that the differing patterns seen in organ parenchymas may be driven purely by the process of cell replacement under different interaction scenarios. PMID:20375040

  6. Characteristic Analysis of Mixed Traffic Flow of Regular and Autonomous Vehicles Using Cellular Automata

    Directory of Open Access Journals (Sweden)

    Yangzexi Liu

    2017-01-01

    Full Text Available The technology of autonomous vehicles is expected to revolutionize the operation of road transport systems. The penetration rate of autonomous vehicles will be low at the early stage of their deployment. It is a challenge to explore the effects of autonomous vehicles and their penetration on heterogeneous traffic flow dynamics. This paper aims to investigate this issue. An improved cellular automaton was employed as the modeling platform for our study. In particular, two sets of rules for lane changing were designed to address mild and aggressive lane changing behavior. With extensive simulation studies, we obtained some promising results. First, the introduction of autonomous vehicles to road traffic could considerably improve traffic flow, particularly the road capacity and free-flow speed. And the level of improvement increases with the penetration rate. Second, the lane-changing frequency between neighboring lanes evolves with traffic density along a fundamental-diagram-like curve. Third, the impacts of autonomous vehicles on the collective traffic flow characteristics are mainly related to their smart maneuvers in lane changing and car following, and it seems that the car-following impact is more pronounced.

  7. Simulation and Experimental Studies on Grain Selection and Structure Design of the Spiral Selector for Casting Single Crystal Ni-Based Superalloy.

    Science.gov (United States)

    Zhang, Hang; Xu, Qingyan

    2017-10-27

    Grain selection is an important process in single crystal turbine blades manufacturing. Selector structure is a control factor of grain selection, as well as directional solidification (DS). In this study, the grain selection and structure design of the spiral selector were investigated through experimentation and simulation. A heat transfer model and a 3D microstructure growth model were established based on the Cellular automaton-Finite difference (CA-FD) method for the grain selector. Consequently, the temperature field, the microstructure and the grain orientation distribution were simulated and further verified. The average error of the temperature result was less than 1.5%. The grain selection mechanisms were further analyzed and validated through simulations. The structural design specifications of the selector were suggested based on the two grain selection effects. The structural parameters of the spiral selector, namely, the spiral tunnel diameter ( d w ), the spiral pitch ( h b ) and the spiral diameter ( h s ), were studied and the design criteria of these parameters were proposed. The experimental and simulation results demonstrated that the improved selector could accurately and efficiently produce a single crystal structure.

  8. Pitting corrosion as a mixed system: coupled deterministic-probabilistic simulation of pit growth

    Science.gov (United States)

    Ibrahim, Israr B. M.; Fonna, S.; Pidaparti, R.

    2018-05-01

    Stochastic behavior of pitting corrosion poses a unique challenge in its computational analysis. However, it also stems from electrochemical activity causing general corrosion. In this paper, a framework for corrosion pit growth simulation based on the coupling of the Cellular Automaton (CA) and Boundary Element Methods (BEM) is presented. The framework assumes that pitting corrosion is controlled by electrochemical activity inside the pit cavity. The BEM provides the prediction of electrochemical activity given the geometrical data and polarization curves, while the CA is used to simulate the evolution of pit shapes based on electrochemical activity provided by BEM. To demonstrate the methodology, a sample case of local corrosion cells formed in pitting corrosion with varied dimensions and polarization functions is considered. Results show certain shapes tend to grow in certain types of environments. Some pit shapes appear to pose a higher risk by being potentially significant stress raisers or potentially increasing the rate of corrosion under the surface. Furthermore, these pits are comparable to commonly observed pit shapes in general corrosion environments.

  9. An extension to Galilean relativity gives rise to quantum mechanics framework

    Science.gov (United States)

    Berkovich, Simon

    The presented scheme for quantum mechanics appeared from considering Cellular Automaton Universe in view of the hidden energy associated with the property of inertia. Galilean relativity states that all inertial frames are equivalent. Our consideration reveals one seemingly small exception - the original frame of reference for the material formations of the Cellular Automaton infrastructure is not isotropic. This frame of reference has a distinctive direction as long as elementary particles of matter are generated by cellular automaton relocations As a result, Cellular Automaton Universe basically complying with the laws of macrophysics for bulk bodies, could exhibit peculiar characteristics for microphysics.. Why the states of microobjects are described by complex numbers is obscure. The observables are presented by real numbers through corresponding macro manipulations. In the inertial frame with unidirectional anisotropy isolated particles are characterized by two numbers; magnitude of their velocity and inclination angle to motion direction. So, these quantum states are mapped to a complex Hilbert space with zero vector representing bulk bodies. The effect of spin may be associated with the sign of the inclination angle trending separations for Stern-Gerlach output and Paul Principle. Emeritus.

  10. Modeling evolution and immune system by cellular automata

    International Nuclear Information System (INIS)

    Bezzi, M.

    2001-01-01

    In this review the behavior of two different biological systems is investigated using cellular automata. Starting from this spatially extended approach it is also tried, in some cases, to reduce the complexity of the system introducing mean-field approximation, and solving (or trying to solve) these simplified systems. It is discussed the biological meaning of the results, the comparison with experimental data (if available) and the different features between spatially extended and mean-field versions. The biological systems considered in this review are the following: Darwinian evolution in simple ecosystems and immune system response. In the first section the main features of molecular evolution are introduced, giving a short survey of genetics for physicists and discussing some models for prebiotic systems and simple ecosystems. It is also introduced a cellular automaton model for studying a set of evolving individuals in a general fitness landscape, considering also the effects of co-evolution. In particular the process of species formation (speciation) is described in sect. 5. The second part deals with immune system modeling. The biological features of immune response are discussed, as well as it is introduced the concept of shape space and of idiotypic network. More detailed reviews which deal with immune system models (mainly focused on idiotypic network models) can be found. Other themes here discussed: the applications of CA to immune system modeling, two complex cellular automata for humoral and cellular immune response. Finally, it is discussed the biological data and the general conclusions are drawn in the last section

  11. Interpretation of Cellular Imaging and AQP4 Quantification Data in a Single Cell Simulator

    Directory of Open Access Journals (Sweden)

    Seon B. Kim

    2014-03-01

    Full Text Available The goal of the present study is to integrate different datasets in cell biology to derive additional quantitative information about a gene or protein of interest within a single cell using computational simulations. We propose a novel prototype cell simulator as a quantitative tool to integrate datasets including dynamic information about transcript and protein levels and the spatial information on protein trafficking in a complex cellular geometry. In order to represent the stochastic nature of transcription and gene expression, our cell simulator uses event-based stochastic simulations to capture transcription, translation, and dynamic trafficking events. In a reconstructed cellular geometry, a realistic microtubule structure is generated with a novel growth algorithm for simulating vesicular transport and trafficking events. In a case study, we investigate the change in quantitative expression levels of a water channel-aquaporin 4-in a single astrocyte cell, upon pharmacological treatment. Gillespie based discrete time approximation method results in stochastic fluctuation of mRNA and protein levels. In addition, we compute the dynamic trafficking of aquaporin-4 on microtubules in this reconstructed astrocyte. Computational predictions are validated with experimental data. The demonstrated cell simulator facilitates the analysis and prediction of protein expression dynamics.

  12. Investigation of high burnup structures in uranium dioxide applying cellular automata: algorithms and codes

    International Nuclear Information System (INIS)

    Akishina, E.P.; Kostenko, B.F.; Ivanov, V.V.

    2003-01-01

    A new method of research in spatial structures that result from uranium dioxide burning in nuclear reactors of modern atomic plants is suggested. The method is based on the presentation of images of the mentioned structures in the form of the working field of a cellular automaton (CA). First, it has allowed one to extract some important quantitative characteristics of the structures directly from the micrographs of the uranium fuel surface. Secondly, the CA has been found out to allow one to formulate easily the dynamics of the evolution of the studied structures in terms of such micrograph elements as spots, spots' boundaries, cracks, etc. Relation has been found between the dynamics and some exactly solvable models of the theory of cellular automata, in particular, the Ising model and the vote model. This investigation gives a detailed description of some CA algorithms which allow one to perform the fuel surface image processing and to model its evolution caused by burnup or chemical etching. (author)

  13. Analysis of stray grain formation in single crystal CMSX-4 superalloy; Analyse der Bildung von Fehlkoernern in einer einkristallinen CMSX-4-Superlegierung

    Energy Technology Data Exchange (ETDEWEB)

    Chmiela, Bartosz; Sozanska, Maria; Cwajna, Jan [Silesian Univ. of Technology, Katowice (Poland). Dept. of Materials Science; Szeliga, Dariusz [Rzeszow Univ. of Technology (Poland). Dept. of Materials Science; Jarczyk, Jerzy [ALD Vacuum Technologies, Hanau (Germany)

    2013-08-01

    Modern single crystal (SX) turbine blades are fabricated by directional solidification using a grain selector. The grain selection process was investigated by numerical simulation and verified by the experiment. A coupled ProCAST and cellular automaton finite element (CAFE) model was used in this study. According to the latest literature data, we designed the grain selector. Simulation confirmed an optimal grain selection efficiency of the applied selector geometry. The obtained experimental results reveal the possibility of stray grain formation in SX castings with a designed selector, in contrast to the simulation results. (orig.)

  14. A federation of simulations based on cellular automata in cyber-physical systems

    Directory of Open Access Journals (Sweden)

    Hoang Van Tran

    2016-02-01

    Full Text Available In cyber-physical system (CPS, cooperation between a variety of computational and physical elements usually poses difficulties to current modelling and simulation tools. Although much research has proposed to address those challenges, most solutions do not completely cover uncertain interactions in CPS. In this paper, we present a new approach to federate simulations for CPS. A federation is a combination of, and coordination between simulations upon a standard of communication. In addition, a mixed simulation is defined as several parallel simulations federated in a common time progress. Such simulations run on the models of physical systems, which are built based on cellular automata theory. The experimental results are performed on a federation of three simulations of forest fire spread, river pollution diffusion and wireless sensor network. The obtained results can be utilized to observe and predict the behaviours of physical systems in their interactions.

  15. Simulation Based Optimization of Complex Monolithic Composite Structures Using Cellular Core Technology

    Science.gov (United States)

    Hickmott, Curtis W.

    Cellular core tooling is a new technology which has the capability to manufacture complex integrated monolithic composite structures. This novel tooling method utilizes thermoplastic cellular cores as inner tooling. The semi-rigid nature of the cellular cores makes them convenient for lay-up, and under autoclave temperature and pressure they soften and expand providing uniform compaction on all surfaces including internal features such as ribs and spar tubes. This process has the capability of developing fully optimized aerospace structures by reducing or eliminating assembly using fasteners or bonded joints. The technology is studied in the context of evaluating its capabilities, advantages, and limitations in developing high quality structures. The complex nature of these parts has led to development of a model using the Finite Element Analysis (FEA) software Abaqus and the plug-in COMPRO Common Component Architecture (CCA) provided by Convergent Manufacturing Technologies. This model utilizes a "virtual autoclave" technique to simulate temperature profiles, resin flow paths, and ultimately deformation from residual stress. A model has been developed simulating the temperature profile during curing of composite parts made with the cellular core technology. While modeling of composites has been performed in the past, this project will look to take this existing knowledge and apply it to this new manufacturing method capable of building more complex parts and develop a model designed specifically for building large, complex components with a high degree of accuracy. The model development has been carried out in conjunction with experimental validation. A double box beam structure was chosen for analysis to determine the effects of the technology on internal ribs and joints. Double box beams were manufactured and sectioned into T-joints for characterization. Mechanical behavior of T-joints was performed using the T-joint pull-off test and compared to traditional

  16. Analytical studies on a modified Nagel-Schreckenberg model with the Fukui-Ishibashi acceleration rule

    International Nuclear Information System (INIS)

    Fu Chuanji; Wang Binghong; Yin Chuanyang; Zhou Tao; Hu Bo; Gao Kun; Hui, P.M.; Hu, C.-K.

    2007-01-01

    We propose and study a one-dimensional traffic flow cellular automaton model of high-speed vehicles with the Fukui-Ishibashi-type (FI) acceleration rule for all cars, and the Nagel-Schreckenberg-type (NS) stochastic delay mechanism. We obtain analytically the fundamental diagrams of the average speed and vehicle flux depending on the vehicle density and stochastic delay probability. Our theoretical results are in excellent agreement with numerical simulations

  17. Design and Realization of an Arabic Morphological Automaton-New Approach for Arabic Morphological Analysis and Generation

    OpenAIRE

    Mourad Gridach; Noureddine Chenfour

    2011-01-01

    Arabic morphological analysis is one of the essential stages in Arabic Natural Language Processing. In this paper we present an approach for Arabic morphological analysis. This approach is based on Arabic morphological automaton (AMAUT). The proposed technique uses a morphological database realized using XMODEL language. Arabic morphology represents a special type of morphological systems because it is based on the concept of scheme to represent Arabic words. We use this concept to develop th...

  18. Archaic man meets a marvellous automaton: posthumanism, social robots, archetypes.

    Science.gov (United States)

    Jones, Raya

    2017-06-01

    Posthumanism is associated with critical explorations of how new technologies are rewriting our understanding of what it means to be human and how they might alter human existence itself. Intersections with analytical psychology vary depending on which technologies are held in focus. Social robotics promises to populate everyday settings with entities that have populated the imagination for millennia. A legend of A Marvellous Automaton appears as early as 350 B.C. in a book of Taoist teachings, and is joined by ancient and medieval legends of manmade humanoids coming to life, as well as the familiar robots of modern science fiction. However, while the robotics industry seems to be realizing an archetypal fantasy, the technology creates new social realities that generate distinctive issues of potential relevance for the theory and practice of analytical psychology. © 2017, The Society of Analytical Psychology.

  19. Simulation of three lanes one-way freeway in low visibility weather by possible traffic accidents

    Science.gov (United States)

    Pang, Ming-bao; Zheng, Sha-sha; Cai, Zhang-hui

    2015-09-01

    The aim of this work is to investigate the traffic impact of low visibility weather on a freeway including the fraction of real vehicle rear-end accidents and road traffic capacity. Based on symmetric two-lane Nagel-Schreckenberg (STNS) model, a cellular automaton model of three-lane freeway mainline with the real occurrence of rear-end accidents in low visibility weather, which considers delayed reaction time and deceleration restriction, was established with access to real-time traffic information of intelligent transportation system (ITS). The characteristics of traffic flow in different visibility weather were discussed via the simulation experiments. The results indicate that incoming flow control (decreasing upstream traffic volume) and inputting variable speed limits (VSL) signal are effective in accident reducing and road actual traffic volume's enhancing. According to different visibility and traffic demand the appropriate control strategies should be adopted in order to not only decrease the probability of vehicle accidents but also avoid congestion.

  20. Idealized Mesoscale Model Simulations of Open Cellular Convection Over the Sea

    DEFF Research Database (Denmark)

    Vincent, Claire Louise; Hahmann, Andrea N.; Kelly, Mark C.

    2012-01-01

    The atmospheric conditions during an observed case of open cellular convection over the North Sea were simulated using the Weather Research and Forecasting (WRF) numerical model. Wind, temperature and water vapour mixing ratio profiles from the WRF simulation were used to initialize an idealized...... version of the model, which excluded the effects of topography, surface inhomogeneities and large-scale weather forcing. Cells with an average diameter of 17.4 km developed. Simulations both with and without a capping inversion were made, and the cell-scale kinetic energy budget was calculated for each...... case. By considering all sources of explicit diffusion in the model, the budgets were balanced. In comparison with previous work based on observational studies, the use of three-dimensional, gridded model data afforded the possibility of calculating all terms in the budgets, which showed...

  1. Ocean acidification affects competition for space: projections of community structure using cellular automata.

    Science.gov (United States)

    McCoy, Sophie J; Allesina, Stefano; Pfister, Catherine A

    2016-03-16

    Historical ecological datasets from a coastal marine community of crustose coralline algae (CCA) enabled the documentation of ecological changes in this community over 30 years in the Northeast Pacific. Data on competitive interactions obtained from field surveys showed concordance between the 1980s and 2013, yet also revealed a reduction in how strongly species interact. Here, we extend these empirical findings with a cellular automaton model to forecast ecological dynamics. Our model suggests the emergence of a new dominant competitor in a global change scenario, with a reduced role of herbivory pressure, or trophic control, in regulating competition among CCA. Ocean acidification, due to its energetic demands, may now instead play this role in mediating competitive interactions and thereby promote species diversity within this guild. © 2016 The Author(s).

  2. Mapping Thermal Habitat of Ectotherms Based on Behavioral Thermoregulation in a Controlled Thermal Environment

    Science.gov (United States)

    Fei, T.; Skidmore, A.; Liu, Y.

    2012-07-01

    Thermal environment is especially important to ectotherm because a lot of physiological functions rely on the body temperature such as thermoregulation. The so-called behavioural thermoregulation function made use of the heterogeneity of the thermal properties within an individual's habitat to sustain the animal's physiological processes. This function links the spatial utilization and distribution of individual ectotherm with the thermal properties of habitat (thermal habitat). In this study we modelled the relationship between the two by a spatial explicit model that simulates the movements of a lizard in a controlled environment. The model incorporates a lizard's transient body temperatures with a cellular automaton algorithm as a way to link the physiology knowledge of the animal with the spatial utilization of its microhabitat. On a larger spatial scale, 'thermal roughness' of the habitat was defined and used to predict the habitat occupancy of the target species. The results showed the habitat occupancy can be modelled by the cellular automaton based algorithm at a smaller scale, and can be modelled by the thermal roughness index at a larger scale.

  3. Neural networks, cellular automata, and robust approach applications for vertex localization in the opera target tracker detector

    International Nuclear Information System (INIS)

    Dmitrievskij, S.G.; Gornushkin, Yu.A.; Ososkov, G.A.

    2005-01-01

    A neural-network (NN) approach for neutrino interaction vertex reconstruction in the OPERA experiment with the help of the Target Tracker (TT) detector is described. A feed-forward NN with the standard back propagation option is used. The energy functional minimization of the network is performed by the method of conjugate gradients. Data preprocessing by means of cellular automaton algorithm is performed. The Hough transform is applied for muon track determination and the robust fitting method is used for shower axis reconstruction. A comparison of the proposed approach with earlier studies, based on the use of the neural network package SNNS, shows their similar performance. The further development of the approach is underway

  4. Using discrete event simulation to change from a functional layout to a cellular layout in an auto parts industry

    Directory of Open Access Journals (Sweden)

    Thiago Buselato Maurício

    2015-07-01

    Full Text Available This paper presents a discrete event simulation employed in a Brazilian automotive company. There was a huge waste caused by one family scrap. It was believed one reason was the company functional layout. In this case, changing from current to cellular layout, employee synergy and knowledge about this family would increase. Due to the complexity for dimensioning a new cellular layout, mainly because of batch size and client’s demand variation. In this case, discrete event simulation was used, which made possible to introduce those effects improving accuracy in final results. This accuracy will be shown by comparing results obtained with simulation and without it (as company used to do. To conclude, cellular layout was responsible for increasing 15% of productivity, reducing lead-time in 7 days and scrap in 15% for this family.

  5. Anomalous spreading of a density front from an infinite continuous source in a concentration-dependent lattice gas automaton diffusion model

    CERN Document Server

    Kuentz, M

    2003-01-01

    A two-dimensional lattice gas automaton (LGA) is used for simulating concentration-dependent diffusion in a microscopically random heterogeneous structure. The heterogeneous medium is initialized at a low density rho sub 0 and then submitted to a steep concentration gradient by continuous injection of particles at a concentration rho sub 1 >rho sub 0 from a one-dimensional source to model spreading of a density front. Whereas the nonlinear diffusion equation generally used to describe concentration-dependent diffusion processes predicts a scaling law of the type phi = xt sup - sup 1 sup / sup 2 in one dimension, the spreading process is shown to deviate from the expected t sup 1 sup / sup 2 scaling. The time exponent is found to be larger than 1/2, i.e. diffusion of the density front is enhanced with respect to standard Fickian diffusion. It is also established that the anomalous time exponent decreases as time elapses: anomalous spreading is thus not a timescaling process. We demonstrate that occurrence of a...

  6. Simulations of living cell origins using a cellular automata model.

    Science.gov (United States)

    Ishida, Takeshi

    2014-04-01

    Understanding the generalized mechanisms of cell self-assembly is fundamental for applications in various fields, such as mass producing molecular machines in nanotechnology. Thus, the details of real cellular reaction networks and the necessary conditions for self-organized cells must be elucidated. We constructed a 2-dimensional cellular automata model to investigate the emergence of biological cell formation, which incorporated a looped membrane and a membrane-bound information system (akin to a genetic code and gene expression system). In particular, with an artificial reaction system coupled with a thermal system, the simultaneous formation of a looped membrane and an inner reaction process resulted in a more stable structure. These double structures inspired the primitive biological cell formation process from chemical evolution stage. With a model to simulate cellular self-organization in a 2-dimensional cellular automata model, 3 phenomena could be realized: (1) an inner reaction system developed as an information carrier precursor (akin to DNA); (2) a cell border emerged (akin to a cell membrane); and (3) these cell structures could divide into 2. This double-structured cell was considered to be a primary biological cell. The outer loop evolved toward a lipid bilayer membrane, and inner polymeric particles evolved toward precursor information carriers (evolved toward DNA). This model did not completely clarify all the necessary and sufficient conditions for biological cell self-organization. Further, our virtual cells remained unstable and fragile. However, the "garbage bag model" of Dyson proposed that the first living cells were deficient; thus, it would be reasonable that the earliest cells were more unstable and fragile than the simplest current unicellular organisms.

  7. WE-DE-202-02: Are Track Structure Simulations Truly Needed for Radiobiology at the Cellular and Tissue Levels?

    International Nuclear Information System (INIS)

    Stewart, R.

    2016-01-01

    Radiation therapy for the treatment of cancer has been established as a highly precise and effective way to eradicate a localized region of diseased tissue. To achieve further significant gains in the therapeutic ratio, we need to move towards biologically optimized treatment planning. To achieve this goal, we need to understand how the radiation-type dependent patterns of induced energy depositions within the cell (physics) connect via molecular, cellular and tissue reactions to treatment outcome such as tumor control and undesirable effects on normal tissue. Several computational biology approaches have been developed connecting physics to biology. Monte Carlo simulations are the most accurate method to calculate physical dose distributions at the nanometer scale, however simulations at the DNA scale are slow and repair processes are generally not simulated. Alternative models that rely on the random formation of individual DNA lesions within one or two turns of the DNA have been shown to reproduce the clusters of DNA lesions, including single strand breaks (SSBs), double strand breaks (DSBs) without the need for detailed track structure simulations. Efficient computational simulations of initial DNA damage induction facilitate computational modeling of DNA repair and other molecular and cellular processes. Mechanistic, multiscale models provide a useful conceptual framework to test biological hypotheses and help connect fundamental information about track structure and dosimetry at the sub-cellular level to dose-response effects on larger scales. In this symposium we will learn about the current state of the art of computational approaches estimating radiation damage at the cellular and sub-cellular scale. How can understanding the physics interactions at the DNA level be used to predict biological outcome? We will discuss if and how such calculations are relevant to advance our understanding of radiation damage and its repair, or, if the underlying biological

  8. WE-DE-202-02: Are Track Structure Simulations Truly Needed for Radiobiology at the Cellular and Tissue Levels?

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, R. [University of Washington (United States)

    2016-06-15

    Radiation therapy for the treatment of cancer has been established as a highly precise and effective way to eradicate a localized region of diseased tissue. To achieve further significant gains in the therapeutic ratio, we need to move towards biologically optimized treatment planning. To achieve this goal, we need to understand how the radiation-type dependent patterns of induced energy depositions within the cell (physics) connect via molecular, cellular and tissue reactions to treatment outcome such as tumor control and undesirable effects on normal tissue. Several computational biology approaches have been developed connecting physics to biology. Monte Carlo simulations are the most accurate method to calculate physical dose distributions at the nanometer scale, however simulations at the DNA scale are slow and repair processes are generally not simulated. Alternative models that rely on the random formation of individual DNA lesions within one or two turns of the DNA have been shown to reproduce the clusters of DNA lesions, including single strand breaks (SSBs), double strand breaks (DSBs) without the need for detailed track structure simulations. Efficient computational simulations of initial DNA damage induction facilitate computational modeling of DNA repair and other molecular and cellular processes. Mechanistic, multiscale models provide a useful conceptual framework to test biological hypotheses and help connect fundamental information about track structure and dosimetry at the sub-cellular level to dose-response effects on larger scales. In this symposium we will learn about the current state of the art of computational approaches estimating radiation damage at the cellular and sub-cellular scale. How can understanding the physics interactions at the DNA level be used to predict biological outcome? We will discuss if and how such calculations are relevant to advance our understanding of radiation damage and its repair, or, if the underlying biological

  9. Simulations of fluid flow through porous media based on cellular automata and non-linear dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, K V

    1992-05-15

    A study is being carried out to apply cellular automata and non-linear dynamics in the construction of efficient and accurate computer simulations of multiphase fluid flow through porous media, with the objective of application to reservoir modelling for hydrocarbon recovery. An algorithm based on Boolean operations has been developed which transforms a PC clone into a highly efficient vector processor capable of cellular automata simulation of single fluid flow through two-dimensional rock matrix models of varying porosities. Macroscopic flow patterns have been established through spatial and temporal averaging with no floating point operations. Permeabilities of the different models have been calculated. Hardware allows the algorithm to function on dual processors on a PC platform using a video recording and editing facility. Very encouraging results have been obtained. 4 figs.

  10. [Evaluation of Cellular Effects Caused by Lunar Regolith Simulant Including Fine Particles].

    Science.gov (United States)

    Horie, Masanori; Miki, Takeo; Honma, Yoshiyuki; Aoki, Shigeru; Morimoto, Yasuo

    2015-06-01

    The National Aeronautics and Space Administration has announced a plan to establish a manned colony on the surface of the moon, and our country, Japan, has declared its participation. The surface of the moon is covered with soil called lunar regolith, which includes fine particles. It is possible that humans will inhale lunar regolith if it is brought into the spaceship. Therefore, an evaluation of the pulmonary effects caused by lunar regolith is important for exploration of the moon. In the present study, we examine the cellular effects of lunar regolith simulant, whose components are similar to those of lunar regolith. We focused on the chemical component and particle size in particular. The regolith simulant was fractionated to lunar regolith simulant such as cell membrane damage, induction of oxidative stress and proinflammatory effect.

  11. Traffic Modelling for Moving-Block Train Control System

    International Nuclear Information System (INIS)

    Tang Tao; Li Keping

    2007-01-01

    This paper presents a new cellular automaton (CA) model for train control system simulation. In the proposed CA model, the driver reactions to train movements are captured by some updated rules. The space-time diagram of traffic flow and the trajectory of train movement is used to obtain insight into the characteristic behavior of railway traffic flow. A number of simulation results demonstrate that the proposed CA model can be successfully used for the simulations of railway traffic. Not only the characteristic behavior of railway traffic flow can be reproduced, but also the simulation values of the minimum time headway are close to the theoretical values.

  12. Modelling of Eutectic Saturation Influence on Microstructure in Thin Wall Ductile Iron Casting Using Cellular Automata

    Directory of Open Access Journals (Sweden)

    Burbelko A.A.

    2012-12-01

    Full Text Available The mathematical model of the globular eutectic solidification in 2D was designed. Proposed model is based on the Cellular Automaton Finite Differences (CA-FD calculation method. Model has been used for studies of the primary austenite and of globular eutectic grains growth during the ductile iron solidification in the thin wall casting. Model takes into account, among other things, non-uniform temperature distribution in the casting wall cross-section, kinetics of the austenite and graphite grains nucleation, and non-equilibrium nature of the interphase boundary migration. Calculation of eutectic saturation influence (Sc = 0.9 - 1.1 on microstructure (austenite and graphite fraction, density of austenite and graphite grains and temperature curves in 2 mm wall ductile iron casting has been done.

  13. A DNA Logic Gate Automaton for Detection of Rabies and Other Lyssaviruses.

    Science.gov (United States)

    Vijayakumar, Pavithra; Macdonald, Joanne

    2017-07-05

    Immediate activation of biosensors is not always desirable, particularly if activation is due to non-specific interactions. Here we demonstrate the use of deoxyribozyme-based logic gate networks arranged into visual displays to precisely control activation of biosensors, and demonstrate a prototype molecular automaton able to discriminate between seven different genotypes of Lyssaviruses, including Rabies virus. The device uses novel mixed-base logic gates to enable detection of the large diversity of Lyssavirus sequence populations, while an ANDNOT logic gate prevents non-specific activation across genotypes. The resultant device provides a user-friendly digital-like, but molecule-powered, dot-matrix text output for unequivocal results read-out that is highly relevant for point of care applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Conway's Game of Life is a near-critical metastable state in the multiverse of cellular automata.

    Science.gov (United States)

    Reia, Sandro M; Kinouchi, Osame

    2014-05-01

    Conway's cellular automaton Game of Life has been conjectured to be a critical (or quasicritical) dynamical system. This criticality is generally seen as a continuous order-disorder transition in cellular automata (CA) rule space. Life's mean-field return map predicts an absorbing vacuum phase (ρ = 0) and an active phase density, with ρ = 0.37, which contrasts with Life's absorbing states in a square lattice, which have a stationary density of ρ(2D) ≈ 0.03. Here, we study and classify mean-field maps for 6144 outer-totalistic CA and compare them with the corresponding behavior found in the square lattice. We show that the single-site mean-field approach gives qualitative (and even quantitative) predictions for most of them. The transition region in rule space seems to correspond to a nonequilibrium discontinuous absorbing phase transition instead of a continuous order-disorder one. We claim that Life is a quasicritical nucleation process where vacuum phase domains invade the alive phase. Therefore, Life is not at the "border of chaos," but thrives on the "border of extinction."

  15. Simulating Quantitative Cellular Responses Using Asynchronous Threshold Boolean Network Ensembles

    Directory of Open Access Journals (Sweden)

    Shah Imran

    2011-07-01

    Full Text Available Abstract Background With increasing knowledge about the potential mechanisms underlying cellular functions, it is becoming feasible to predict the response of biological systems to genetic and environmental perturbations. Due to the lack of homogeneity in living tissues it is difficult to estimate the physiological effect of chemicals, including potential toxicity. Here we investigate a biologically motivated model for estimating tissue level responses by aggregating the behavior of a cell population. We assume that the molecular state of individual cells is independently governed by discrete non-deterministic signaling mechanisms. This results in noisy but highly reproducible aggregate level responses that are consistent with experimental data. Results We developed an asynchronous threshold Boolean network simulation algorithm to model signal transduction in a single cell, and then used an ensemble of these models to estimate the aggregate response across a cell population. Using published data, we derived a putative crosstalk network involving growth factors and cytokines - i.e., Epidermal Growth Factor, Insulin, Insulin like Growth Factor Type 1, and Tumor Necrosis Factor α - to describe early signaling events in cell proliferation signal transduction. Reproducibility of the modeling technique across ensembles of Boolean networks representing cell populations is investigated. Furthermore, we compare our simulation results to experimental observations of hepatocytes reported in the literature. Conclusion A systematic analysis of the results following differential stimulation of this model by growth factors and cytokines suggests that: (a using Boolean network ensembles with asynchronous updating provides biologically plausible noisy individual cellular responses with reproducible mean behavior for large cell populations, and (b with sufficient data our model can estimate the response to different concentrations of extracellular ligands. Our

  16. Neuro-Fuzzy Prediction of Cooperation Interaction Profile of Flexible Road Train Based on Hybrid Automaton Modeling

    Directory of Open Access Journals (Sweden)

    Banjanovic-Mehmedovic Lejla

    2016-01-01

    Full Text Available Accurate prediction of traffic information is important in many applications in relation to Intelligent Transport systems (ITS, since it reduces the uncertainty of future traffic states and improves traffic mobility. There is a lot of research done in the field of traffic information predictions such as speed, flow and travel time. The most important research was done in the domain of cooperative intelligent transport system (C-ITS. The goal of this paper is to introduce the novel cooperation behaviour profile prediction through the example of flexible Road Trains useful road cooperation parameter, which contributes to the improvement of traffic mobility in Intelligent Transportation Systems. This paper presents an approach towards the control and cooperation behaviour modelling of vehicles in the flexible Road Train based on hybrid automaton and neuro-fuzzy (ANFIS prediction of cooperation profile of the flexible Road Train. Hybrid automaton takes into account complex dynamics of each vehicle as well as discrete cooperation approach. The ANFIS is a particular class of the ANN family with attractive estimation and learning potentials. In order to provide statistical analysis, RMSE (root mean square error, coefficient of determination (R2 and Pearson coefficient (r, were utilized. The study results suggest that ANFIS would be an efficient soft computing methodology, which could offer precise predictions of cooperative interactions between vehicles in Road Train, which is useful for prediction mobility in Intelligent Transport systems.

  17. Numerical simulations of cellular detonation diffraction in a stable gaseous mixture

    Directory of Open Access Journals (Sweden)

    Jian Li

    2016-09-01

    Full Text Available In this paper, the diffraction phenomenon of gaseous cellular detonations emerging from a confined tube into a sudden open space is simulated using the reactive Euler equations with a two-step Arrhenius chemistry model. Both two-dimensional and axisymmetric configurations are used for modeling cylindrical and spherical expansions, respectively. The chemical parameters are chosen for a stable gaseous explosive mixture in which the cellular detonation structure is highly regular. Adaptive mesh refinement (AMR is used to resolve the detonation wave structure and its evolution during the transmission. The numerical results show that the critical channel width and critical diameter over the detonation cell size are about 13±1 and 25±1, respectively. These numerical findings are comparable with the experimental observation and confirm again that the critical channel width and critical diameter differ essentially by a factor close to 2, equal to the geometrical scaling based on front curvature theory. Unlike unstable mixtures where instabilities manifested in the detonation front structure play a significant role during the transmission, the present numerical results and the observed geometrical scaling provide again evidence that the failure of detonation diffraction in stable mixtures with a regular detonation cellular pattern is dominantly caused by the global curvature due to the wave divergence resulting in the global decoupling of the reaction zone with the expanding shock front.

  18. The cellular automaton interpretation of quantum mechanics

    CERN Document Server

    't Hooft, Gerard

    2016-01-01

    This book presents the deterministic view of quantum mechanics developed by Nobel Laureate Gerard 't Hooft. Dissatisfied with the uncomfortable gaps in the way conventional quantum mechanics meshes with the classical world, 't Hooft has revived the old hidden variable ideas, but now in a much more systematic way than usual. In this, quantum mechanics is viewed as a tool rather than a theory. The book presents examples of models that are classical in essence, but can be analysed by the use of quantum techniques, and argues that even the Standard Model, together with gravitational interactions, might be viewed as a quantum mechanical approach to analysing a system that could be classical at its core. He shows how this approach, even though it is based on hidden variables, can be plausibly reconciled with Bell's theorem, and how the usual objections voiced against the idea of ‘superdeterminism' can be overcome, at least in principle. This framework elegantly explains - and automatically cures - the problems of...

  19. A minimalist model of characteristic earthquakes

    DEFF Research Database (Denmark)

    Vázquez-Prada, M.; González, Á.; Gómez, J.B.

    2002-01-01

    In a spirit akin to the sandpile model of self- organized criticality, we present a simple statistical model of the cellular-automaton type which simulates the role of an asperity in the dynamics of a one-dimensional fault. This model produces an earthquake spectrum similar to the characteristic-earthquake...... behaviour of some seismic faults. This model, that has no parameter, is amenable to an algebraic description as a Markov Chain. This possibility illuminates some important results, obtained by Monte Carlo simulations, such as the earthquake size-frequency relation and the recurrence time...... of the characteristic earthquake....

  20. A cardiac electrical activity model based on a cellular automata system in comparison with neural network model.

    Science.gov (United States)

    Khan, Muhammad Sadiq Ali; Yousuf, Sidrah

    2016-03-01

    Cardiac Electrical Activity is commonly distributed into three dimensions of Cardiac Tissue (Myocardium) and evolves with duration of time. The indicator of heart diseases can occur randomly at any time of a day. Heart rate, conduction and each electrical activity during cardiac cycle should be monitor non-invasively for the assessment of "Action Potential" (regular) and "Arrhythmia" (irregular) rhythms. Many heart diseases can easily be examined through Automata model like Cellular Automata concepts. This paper deals with the different states of cardiac rhythms using cellular automata with the comparison of neural network also provides fast and highly effective stimulation for the contraction of cardiac muscles on the Atria in the result of genesis of electrical spark or wave. The specific formulated model named as "States of automaton Proposed Model for CEA (Cardiac Electrical Activity)" by using Cellular Automata Methodology is commonly shows the three states of cardiac tissues conduction phenomena (i) Resting (Relax and Excitable state), (ii) ARP (Excited but Absolutely refractory Phase i.e. Excited but not able to excite neighboring cells) (iii) RRP (Excited but Relatively Refractory Phase i.e. Excited and able to excite neighboring cells). The result indicates most efficient modeling with few burden of computation and it is Action Potential during the pumping of blood in cardiac cycle.

  1. Two-material optimization of plate armour for blast mitigation using hybrid cellular automata

    Science.gov (United States)

    Goetz, J.; Tan, H.; Renaud, J.; Tovar, A.

    2012-08-01

    With the increased use of improvised explosive devices in regions at war, the threat to military and civilian life has risen. Cabin penetration and gross acceleration are the primary threats in an explosive event. Cabin penetration crushes occupants, damaging the lower body. Acceleration causes death at high magnitudes. This investigation develops a process of designing armour that simultaneously mitigates cabin penetration and acceleration. The hybrid cellular automaton (HCA) method of topology optimization has proven efficient and robust in problems involving large, plastic deformations such as crash impact. Here HCA is extended to the design of armour under blast loading. The ability to distribute two metallic phases, as opposed to one material and void, is also added. The blast wave energy transforms on impact into internal energy (IE) inside the solid medium. Maximum attenuation occurs with maximized IE. The resulting structures show HCA's potential for designing blast mitigating armour structures.

  2. Complex traffic flow that allows as well as hampers lane-changing intrinsically contains social-dilemma structures

    Science.gov (United States)

    Iwamura, Yoshiro; Tanimoto, Jun

    2018-02-01

    To investigate an interesting question as to whether or not social dilemma structures can be found in a realistic traffic flow reproduced by a model, we built a new microscopic model in which an intentional driver may try lane-changing to go in front of other vehicles and may hamper others’ lane-changes. Our model consists of twofold parts; cellular automaton emulating a real traffic flow and evolutionary game theory to implement a driver’s decision making-process. Numerical results reveal that a social dilemma like the multi-player chicken game or prisoner’s dilemma game emerges depending on the traffic phase. This finding implies that a social dilemma, which has been investigated by applied mathematics so far, hides behind a traffic flow, which has been explored by fluid dynamics. Highlight - Complex system of traffic flow with consideration of driver’s decision making process is concerned. - A new model dovetailing cellular automaton with game theory is established. - Statistical result from numerical simulations reveals a social dilemma structure underlying traffic flow. - The social dilemma is triggered by a driver’s egocentric actions of lane-changing and hampering other’s lane-change.

  3. Comparative Study of Aircraft Boarding Strategies Using Cellular Discrete Event Simulation

    Directory of Open Access Journals (Sweden)

    Shafagh Jafer

    2017-11-01

    Full Text Available Time is crucial in the airlines industry. Among all factors contributing to an aircraft turnaround time; passenger boarding delays is the most challenging one. Airlines do not have control over the behavior of passengers; thus, focusing their effort on reducing passenger boarding time through implementing efficient boarding strategies. In this work, we attempt to use cellular Discrete-Event System Specification (Cell-DEVS modeling and simulation to provide a comprehensive evaluation of aircraft boarding strategies. We have developed a simulation benchmark consisting of eight boarding strategies including Back-to-Front; Window Middle Aisle; Random; Zone Rotate; Reverse Pyramid; Optimal; Optimal Practical; and Efficient. Our simulation models are scalable and adaptive; providing a powerful analysis apparatus for investigating any existing or yet to be discovered boarding strategy. We explain the details of our models and present the results both visually and numerically to evaluate the eight implemented boarding strategies. We also compare our results with other studies that have used different modeling techniques; reporting nearly identical performance results. The simulations revealed that Window Middle Aisle provides the least boarding delay; with a small fraction of time difference compared to the optimal strategy. The results of this work could highly benefit the commercial airlines industry by optimizing and reducing passenger boarding delays.

  4. Cellular modelling of secondary radial growth in conifer trees: application to Pinus radiata (D. Don).

    Science.gov (United States)

    Forest, Loïc; Demongeot, Jacques; Demongeota, Jacques

    2006-05-01

    The radial growth of conifer trees proceeds from the dynamics of a merismatic tissue called vascular cambium or cambium. Cambium is a thin layer of active proliferating cells. The purpose of this paper was to model the main characteristics of cambial activity and its consecutive radial growth. Cell growth is under the control of the auxin hormone indole-3-acetic. The model is composed of a discrete part, which accounts for cellular proliferation, and a continuous part involving the transport of auxin. Cambium is modeled in a two-dimensional cross-section by a cellular automaton that describes the set of all its constitutive cells. Proliferation is defined as growth and division of cambial cells under neighbouring constraints, which can eliminate some cells from the cambium. The cell-growth rate is determined from auxin concentration, calculated with the continuous model. We studied the integration of each elementary cambial cell activity into the global coherent movement of macroscopic morphogenesis. Cases of normal and abnormal growth of Pinus radiata (D. Don) are modelled. Abnormal growth includes deformed trees where gravity influences auxin transport, producing heterogeneous radial growth. Cross-sectional microscopic views are also provided to validate the model's hypothesis and results.

  5. Cellular modeling of fault-tolerant multicomputers

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, G

    1987-01-01

    Work described was concerned with a novel method for investigation of fault tolerance in large regular networks of computers. Motivation was to provide a technique useful in rapid evaluation of highly reliable systems that exploit the low cost and ease of volume production of simple microcomputer components. First, a system model and simulator based upon cellular automata are developed. This model is characterized by its simplicity and ease of modification when adapting to new types of network. Second, in order to test and verify the predictive capabilities of the cellular system, a more-detailed simulation is performed based upon an existing computational model, that of the Transputer. An example application is used to exercise various systems designed using the cellular model. Using this simulator, experimental results are obtained both for existing well-understood configurations and for more novel types also developed here. In all cases it was found that the cellular model and simulator successfully predicted the ranking in reliability improvement of the systems studied.

  6. Cellular automata analysis and applications

    CERN Document Server

    Hadeler, Karl-Peter

    2017-01-01

    This book focuses on a coherent representation of the main approaches to analyze the dynamics of cellular automata. Cellular automata are an inevitable tool in mathematical modeling. In contrast to classical modeling approaches as partial differential equations, cellular automata are straightforward to simulate but hard to analyze. In this book we present a review of approaches and theories that allow the reader to understand the behavior of cellular automata beyond simulations. The first part consists of an introduction of cellular automata on Cayley graphs, and their characterization via the fundamental Cutis-Hedlund-Lyndon theorems in the context of different topological concepts (Cantor, Besicovitch and Weyl topology). The second part focuses on classification results: What classification follows from topological concepts (Hurley classification), Lyapunov stability (Gilman classification), and the theory of formal languages and grammars (Kůrka classification). These classifications suggest to cluster cel...

  7. Monte Carlo simulations of the cellular S-value, lineal energy and RBE for BNCT

    International Nuclear Information System (INIS)

    Liu Chingsheng; Tung Chuanjong

    2006-01-01

    Due to the non-uniform uptake of boron-containing pharmaceuticals in cells and the short-ranged alpha and lithium particles, microdosimetry provides useful information on the cellular dose and response of boron neutron capture therapy (BNCT). Radiation dose and quality in BNCT may be expressed in terms of the cellular S-value and the lineal energy spectrum. In the present work, Monte Carlo simulations were performed to calculate these microdosimetric parameters for different source-target configurations and sizes in cells. The effective relative biological effectiveness (RBE) of the Tsing Hua Open-pool Reactor (THOR) epithermal neutron beam was evaluated using biological weighting functions that depended on the lineal energy. RBE changes with source-target configurations and sizes were analyzed. (author)

  8. Direct numerical simulation of cellular-scale blood flow in microvascular networks

    Science.gov (United States)

    Balogh, Peter; Bagchi, Prosenjit

    2017-11-01

    A direct numerical simulation method is developed to study cellular-scale blood flow in physiologically realistic microvascular networks that are constructed in silico following published in vivo images and data, and are comprised of bifurcating, merging, and winding vessels. The model resolves large deformation of individual red blood cells (RBC) flowing in such complex networks. The vascular walls and deformable interfaces of the RBCs are modeled using the immersed-boundary methods. Time-averaged hemodynamic quantities obtained from the simulations agree quite well with published in vivo data. Our simulations reveal that in several vessels the flow rates and pressure drops could be negatively correlated. The flow resistance and hematocrit are also found to be negatively correlated in some vessels. These observations suggest a deviation from the classical Poiseuille's law in such vessels. The cells are observed to frequently jam at vascular bifurcations resulting in reductions in hematocrit and flow rate in the daughter and mother vessels. We find that RBC jamming results in several orders of magnitude increase in hemodynamic resistance, and thus provides an additional mechanism of increased in vivo blood viscosity as compared to that determined in vitro. Funded by NSF CBET 1604308.

  9. Simulation of skill acquisition in sequential learning of a computer game

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Nielsen, Finn Ravnsbjerg; Rasmussen, Jens

    1995-01-01

    The paper presents some theoretical assumptions about the cognitive control mechanisms of subjects learning to play a computer game. A simulation model has been developed to investigate these assumptions. The model is an automaton, reacting to instruction-like cue action rules. The prototypical...... performances of 23 experimental subjects at succeeding levels of training are compared to the performance of the model. The findings are interpreted in terms of a general taxonomy for cognitive task analysis....

  10. Evolving cellular automata for diversity generation and pattern recognition: deterministic versus random strategy

    International Nuclear Information System (INIS)

    De Menezes, Marcio Argollo; Brigatti, Edgardo; Schwämmle, Veit

    2013-01-01

    Microbiological systems evolve to fulfil their tasks with maximal efficiency. The immune system is a remarkable example, where the distinction between self and non-self is made by means of molecular interaction between self-proteins and antigens, triggering affinity-dependent systemic actions. Specificity of this binding and the infinitude of potential antigenic patterns call for novel mechanisms to generate antibody diversity. Inspired by this problem, we develop a genetic algorithm where agents evolve their strings in the presence of random antigenic strings and reproduce with affinity-dependent rates. We ask what is the best strategy to generate diversity if agents can rearrange their strings a finite number of times. We find that endowing each agent with an inheritable cellular automaton rule for performing rearrangements makes the system more efficient in pattern-matching than if transformations are totally random. In the former implementation, the population evolves to a stationary state where agents with different automata rules coexist. (paper)

  11. APRON: A Cellular Processor Array Simulation and Hardware Design Tool

    Science.gov (United States)

    Barr, David R. W.; Dudek, Piotr

    2009-12-01

    We present a software environment for the efficient simulation of cellular processor arrays (CPAs). This software (APRON) is used to explore algorithms that are designed for massively parallel fine-grained processor arrays, topographic multilayer neural networks, vision chips with SIMD processor arrays, and related architectures. The software uses a highly optimised core combined with a flexible compiler to provide the user with tools for the design of new processor array hardware architectures and the emulation of existing devices. We present performance benchmarks for the software processor array implemented on standard commodity microprocessors. APRON can be configured to use additional processing hardware if necessary and can be used as a complete graphical user interface and development environment for new or existing CPA systems, allowing more users to develop algorithms for CPA systems.

  12. APRON: A Cellular Processor Array Simulation and Hardware Design Tool

    Directory of Open Access Journals (Sweden)

    David R. W. Barr

    2009-01-01

    Full Text Available We present a software environment for the efficient simulation of cellular processor arrays (CPAs. This software (APRON is used to explore algorithms that are designed for massively parallel fine-grained processor arrays, topographic multilayer neural networks, vision chips with SIMD processor arrays, and related architectures. The software uses a highly optimised core combined with a flexible compiler to provide the user with tools for the design of new processor array hardware architectures and the emulation of existing devices. We present performance benchmarks for the software processor array implemented on standard commodity microprocessors. APRON can be configured to use additional processing hardware if necessary and can be used as a complete graphical user interface and development environment for new or existing CPA systems, allowing more users to develop algorithms for CPA systems.

  13. Implementation of CAVENET and Its Usage for Performance Evaluation of AODV, OLSR and DYMO Protocols in Vehicular Networks

    Directory of Open Access Journals (Sweden)

    Evjola Spaho

    2010-01-01

    Full Text Available Vehicle Ad-hoc Network (VANET is a kind of Mobile Ad-hoc Network (MANET that establishes wireless connection between cars. In VANETs and MANETs, the topology of the network changes very often, therefore implementation of efficient routing protocols is very important problem. In MANETs, the Random Waypoint (RW model is used as a simulation model for generating node mobility pattern. On the other hand, in VANETs, the mobility patterns of nodes is restricted along the roads, and is affected by the movement of neighbour nodes. In this paper, we present a simulation system for VANET called CAVENET (Cellular Automaton based VEhicular NETwork. In CAVENET, the mobility patterns of nodes are generated by an 1-dimensional cellular automata. We improved CAVENET and implemented some routing protocols. We investigated the performance of the implemented routing protocols by CAVENET. The simulation results have shown that DYMO protocol has better performance than AODV and OLSR protocols.

  14. Multi-layer composite mechanical modeling for the inhomogeneous biofilm mechanical behavior.

    Science.gov (United States)

    Wang, Xiaoling; Han, Jingshi; Li, Kui; Wang, Guoqing; Hao, Mudong

    2016-08-01

    Experiments showed that bacterial biofilms are heterogeneous, for example, the density, the diffusion coefficient, and mechanical properties of the biofilm are different along the biofilm thickness. In this paper, we establish a multi-layer composite model to describe the biofilm mechanical inhomogeneity based on unified multiple-component cellular automaton (UMCCA) model. By using our model, we develop finite element simulation procedure for biofilm tension experiment. The failure limit and biofilm extension displacement obtained from our model agree well with experimental measurements. This method provides an alternative theory to study the mechanical inhomogeneity in biological materials.

  15. THE EFFECT OF CELLULAR PHONE USE ON DRIVING PERFORMANCE

    OpenAIRE

    Toshiro ISHIDA

    2001-01-01

    Many experiments using driving simulators or real roads have shown that using a cellular phone while driving may cause an accident because it delays visual information processing by the driver. In this research, we examined the influence on driving performance of cellular phone use on a course that simulated streets. Driving conditions were driving only, listening to the car radio, hands-free cellular phone use and using a cellular phone with the left hand. Driving performance measurements in...

  16. USE OF AN AUTOMATON MODEL FOR THE DESIGNING OF REAL-TIME INFORMATION SYSTEMS IN THE RAILWAY STATIONS

    Directory of Open Access Journals (Sweden)

    Igor ZHUKOVYTS’KYY

    2017-12-01

    Full Text Available The author proposes to develop special models that are built based on finite-state machine, Mealy, in order to display information about technological processes at railway stations. The input alphabet of such machines is represented by the real signals (from the floor equipment, the related information systems and the dispatch office personnel. This representation allows one to formalize the software design process of real-time information management systems for these technological processes. The article demonstrates the possibility of formal transition from the automaton model to the software algorithms. The proposed approach was tested when designing the information system for Nizhnedneprovsk junction railway yard.

  17. [Simulation of urban ecological security pattern based on cellular automata: a case of Dongguan City, Guangdong Province of South China].

    Science.gov (United States)

    Yang, Qing-Sheng; Qiao, Ji-Gang; Ai, Bin

    2013-09-01

    Taking the Dongguan City with rapid urbanization as a case, and selecting landscape ecological security level as evaluation criterion, the urbanization cellular number of 1 km x 1 km ecological security cells was obtained, and imbedded into the transition rules of cellular automata (CA) as the restraint term to control urban development, establish ecological security urban CA, and simulate ecological security urban development pattern. The results showed the integrated landscape ecological security index of the City decreased from 0.497 in 1998 to 0.395 in 2005, indicating that the ecological security at landscape scale was decreased. The CA-simulated integrated ecological security index of the City in 2005 was increased from the measured 0.395 to 0.479, showing that the simulated urban landscape ecological pressure from human became lesser, ecological security became better, and integrated landscape ecological security became higher. CA could be used as an effective tool in researching urban ecological security.

  18. Lattice gas automaton scheme with stochastic particle movement for a rotated fluid flow

    International Nuclear Information System (INIS)

    Ishiguro, Misako

    2002-01-01

    Lattice gas automaton (LGA) models developed so far are just for Cartesian geometries, and no direct approach to rotated fluid flows is found. In this paper, LGA method is applied to model a two-dimensional rotated flow. Several problems specific to the rotated flow are to be solved: hexagonal lattice geometry to effectively identify the neighbors, boundary condition for irregular walls, multi-speed scheme to represent angular-oriented fluid velocity υ θ ≅γω, shape of macroscopic domain for statistics, formula to obtain macroscopic quantities such as density and mean fluid velocities, application method of Fermi-Dirac function to the initial particle arrangement. For this purpose, FHP-I type hexagonal lattice model is revised and a new LGA model with stochastic particle movement is proposed. The results of the trial calculation are shown. It is also investigated whether or not the underlying microscopic Boolean equations newly introduced leads to Navier-Stokes equation. (author)

  19. Estimating cellular network performance during hurricanes

    International Nuclear Information System (INIS)

    Booker, Graham; Torres, Jacob; Guikema, Seth; Sprintson, Alex; Brumbelow, Kelly

    2010-01-01

    Cellular networks serve a critical role during and immediately after a hurricane, allowing citizens to contact emergency services when land-line communication is lost and serving as a backup communication channel for emergency responders. However, due to their ubiquitous deployment and limited design for extreme loading events, basic network elements, such as cellular towers and antennas are prone to failures during adverse weather conditions such as hurricanes. Accordingly, a systematic and computationally feasible approach is required for assessing and improving the reliability of cellular networks during hurricanes. In this paper we develop a new multi-disciplinary approach to efficiently and accurately assess cellular network reliability during hurricanes. We show how the performance of a cellular network during and immediately after future hurricanes can be estimated based on a combination of hurricane wind field models, structural reliability analysis, Monte Carlo simulation, and cellular network models and simulation tools. We then demonstrate the use of this approach for assessing the improvement in system reliability that can be achieved with discrete topological changes in the system. Our results suggest that adding redundancy, particularly through a mesh topology or through the addition of an optical fiber ring around the perimeter of the system can be an effective way to significantly increase the reliability of some cellular systems during hurricanes.

  20. Spatial patterns and scale freedom in Prisoner's Dilemma cellular automata with Pavlovian strategies

    Science.gov (United States)

    Fort, H.; Viola, S.

    2005-01-01

    A cellular automaton in which cells represent agents playing the Prisoner's Dilemma (PD) game following the simple 'win—stay, lose—shift' strategy is studied. Individuals with binary behaviour, such that they can either cooperate (C) or defect (D), play repeatedly with their neighbours (Von Neumann's and Moore's neighbourhoods). Their utilities in each round of the game are given by a rescaled pay-off matrix described by a single parameter τ, which measures the ratio of temptation to defect to reward for cooperation. Depending on the region of the parameter space τ, the system self-organizes—after a transient—into dynamical equilibrium states characterized by different definite fractions of C agents \\bar {c}_\\infty (two states for the von Neumann neighbourhood and four for the Moore neighbourhood). For some ranges of τ the cluster size distributions, the power spectra P(f) and the perimeter-area curves follow power law scalings. Percolation below threshold is also found for D agent clusters. We also analyse the asynchronous dynamics version of this model and compare results.

  1. Bridging the gap: linking molecular simulations and systemic descriptions of cellular compartments.

    Directory of Open Access Journals (Sweden)

    Tihamér Geyer

    Full Text Available Metabolic processes in biological cells are commonly either characterized at the level of individual enzymes and metabolites or at the network level. Often these two paradigms are considered as mutually exclusive because concepts from neither side are suited to describe the complete range of scales. Additionally, when modeling metabolic or regulatory cellular systems, often a large fraction of the required kinetic parameters are unknown. This even applies to such simple and extensively studied systems like the photosynthetic apparatus of purple bacteria. Using the chromatophore vesicles of Rhodobacter sphaeroides as a model system, we show that a consistent kinetic model emerges when fitting the dynamics of a molecular stochastic simulation to a set of time dependent experiments even though about two thirds of the kinetic parameters in this system are not known from experiment. Those kinetic parameters that were previously known all came out in the expected range. The simulation model was built from independent protein units composed of elementary reactions processing single metabolites. This pools-and-proteins approach naturally compiles the wealth of available molecular biological data into a systemic model and can easily be extended to describe other systems by adding new protein or nucleic acid types. The automated parameter optimization, performed with an evolutionary algorithm, reveals the sensitivity of the model to the value of each parameter and the relative importances of the experiments used. Such an analysis identifies the crucial system parameters and guides the setup of new experiments that would add most knowledge for a systemic understanding of cellular compartments. The successful combination of the molecular model and the systemic parametrization presented here on the example of the simple machinery for bacterial photosynthesis shows that it is actually possible to combine molecular and systemic modeling. This framework can now

  2. Dynamic behavior of cellular materials and cellular structures: Experiments and modeling

    Science.gov (United States)

    Gao, Ziyang

    Cellular solids, including cellular materials and cellular structures (CMS), have attracted people's great interests because of their low densities and novel physical, mechanical, thermal, electrical and acoustic properties. They offer potential for lightweight structures, energy absorption, thermal management, etc. Therefore, the studies of cellular solids have become one of the hottest research fields nowadays. From energy absorption point of view, any plastically deformed structures can be divided into two types (called type I and type II), and the basic cells of the CMS may take the configurations of these two types of structures. Accordingly, separated discussions are presented in this thesis. First, a modified 1-D model is proposed and numerically solved for a typical type II structure. Good agreement is achieved with the previous experimental data, hence is used to simulate the dynamic behavior of a type II chain. Resulted from different load speeds, interesting collapse modes are observed, and the parameters which govern the cell's post-collapse behavior are identified through a comprehensive non-dimensional analysis on general cellular chains. Secondly, the MHS specimens are chosen as an example of type I foam materials because of their good uniformity of the cell geometry. An extensive experimental study was carried out, where more attention was paid to their responses to dynamic loadings. Great enhancement of the stress-strain curve was observed in dynamic cases, and the energy absorption capacity is found to be several times higher than that of the commercial metal foams. Based on the experimental study, finite elemental simulations and theoretical modeling are also conducted, achieving good agreements and demonstrating the validities of those models. It is believed that the experimental, numerical and analytical results obtained in the present study will certainly deepen the understanding of the unsolved fundamental issues on the mechanical behavior of

  3. Traffic dynamics around weaving section influenced by accident: Cellular automata approach

    Science.gov (United States)

    Kong, Lin-Peng; Li, Xin-Gang; Lam, William H. K.

    2015-07-01

    The weaving section, as a typical bottleneck, is one source of vehicle conflicts and an accident-prone area. Traffic accident will block lanes and the road capacity will be reduced. Several models have been established to study the dynamics around traffic bottlenecks. However, little attention has been paid to study the complex traffic dynamics influenced by the combined effects of bottleneck and accident. This paper presents a cellular automaton model to characterize accident-induced traffic behavior around the weaving section. Some effective control measures are proposed and verified for traffic management under accident condition. The total flux as a function of inflow rates, the phase diagrams, the spatial-temporal diagrams, and the density and velocity profiles are presented to analyze the impact of accident. It was shown that the proposed control measures for weaving traffic can improve the capacity of weaving section under both normal and accident conditions; the accidents occurring on median lane in the weaving section are more inclined to cause traffic jam and reduce road capacity; the capacity of weaving section will be greatly reduced when the accident happens downstream the weaving section.

  4. Synchronization, TIGoRS, and Information Flow in Complex Systems: Dispositional Cellular Automata.

    Science.gov (United States)

    Sulis, William H

    2016-04-01

    Synchronization has a long history in physics where it refers to the phase matching of two identical oscillators. This notion has been extensively studied in physics as well as in biology, where it has been applied to such widely varying phenomena as the flashing of fireflies and firing of neurons in the brain. Human behavior, however, may be recurrent but it is not oscillatory even though many physiological systems do exhibit oscillatory tendencies. Moreover, much of human behaviour is collaborative and cooperative, where the individual behaviours may be distinct yet contemporaneous (if not simultaneous) and taken collectively express some functionality. In the context of behaviour, the important aspect is the repeated co-occurrence in time of behaviours that facilitate the propagation of information or of functionality, regardless of whether or not these behaviours are similar or identical. An example of this weaker notion of synchronization is transient induced global response synchronization (TIGoRS). Previous work has shown that TIGoRS is a ubiquitous phenomenon among complex systems, enabling them to stably parse environmental transients into salient units to which they stably respond. This leads to the notion of Sulis machines, which emergently generate a primitive linguistic structure through their dynamics. This article reviews the notion of TIGoRS and its expression in several complex systems models including tempered neural networks, driven cellular automata and cocktail party automata. The emergent linguistics of Sulis machines are discussed. A new class of complex systems model, the dispositional cellular automaton is introduced. A new metric for TIGoRS, the excess synchronization, is introduced and applied to the study of TIGoRS in dispositional cellular automata. It is shown that these automata exhibit a nonlinear synchronization response to certain perturbing transients.

  5. Spatial distribution patterns of energy deposition and cellular radiation effects in lung tissue following simulated exposure to alpha particles

    International Nuclear Information System (INIS)

    Hofmann, W.; Crawford-Brown, D.J.

    1990-01-01

    Randomly oriented sections of rat tissue have been digitised to provide the contours of tissue-air interfaces and the locations of individual cell nuclei in the alveolated region of the lung. Sources of alpha particles with varying irradiation geometries and densities are simulated to compute the resulting random pattern of cellular irradiation, i.e. spatial coordinates, frequency, track length, and energy of traversals by the emitted alpha particles. Probabilities per unit track lengths, derived from experimental data on in vitro cellular inactivation and transformation, are then applied to the results of the alpha exposure simulations to yield an estimate of the number of both dead and viable transformed cells and their spatial distributions. If lung cancer risk is linearly related to the number of transformed cells, the carcinogenic risk for hot particles is always smaller than that for a uniform nuclide distribution of the same activity. (author)

  6. Micro-simulation of vehicle conflicts involving right-turn vehicles at signalized intersections based on cellular automata.

    Science.gov (United States)

    Chai, C; Wong, Y D

    2014-02-01

    At intersection, vehicles coming from different directions conflict with each other. Improper geometric design and signal settings at signalized intersection will increase occurrence of conflicts between road users and results in a reduction of the safety level. This study established a cellular automata (CA) model to simulate vehicular interactions involving right-turn vehicles (as similar to left-turn vehicles in US). Through various simulation scenarios for four case cross-intersections, the relationships between conflict occurrences involving right-turn vehicles with traffic volume and right-turn movement control strategies are analyzed. Impacts of traffic volume, permissive right-turn compared to red-amber-green (RAG) arrow, shared straight-through and right-turn lane as well as signal setting are estimated from simulation results. The simulation model is found to be able to provide reasonable assessment of conflicts through comparison of existed simulation approach and observed accidents. Through the proposed approach, prediction models for occurrences and severity of vehicle conflicts can be developed for various geometric layouts and traffic control strategies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Simulation of Corrosion Process for Structure with the Cellular Automata Method

    Science.gov (United States)

    Chen, M. C.; Wen, Q. Q.

    2017-06-01

    In this paper, from the mesoscopic point of view, under the assumption of metal corrosion damage evolution being a diffusive process, the cellular automata (CA) method was proposed to simulate numerically the uniform corrosion damage evolution of outer steel tube of concrete filled steel tubular columns subjected to corrosive environment, and the effects of corrosive agent concentration, dissolution probability and elapsed etching time on the corrosion damage evolution were also investigated. It was shown that corrosion damage increases nonlinearly with increasing elapsed etching time, and the longer the etching time, the more serious the corrosion damage; different concentration of corrosive agents had different impacts on the corrosion damage degree of the outer steel tube, but the difference between the impacts was very small; the heavier the concentration, the more serious the influence. The greater the dissolution probability, the more serious the corrosion damage of the outer steel tube, but with the increase of dissolution probability, the difference between its impacts on the corrosion damage became smaller and smaller. To validate present method, corrosion damage measurements for concrete filled square steel tubular columns (CFSSTCs) sealed at both their ends and immersed fully in a simulating acid rain solution were conducted, and Faraday’s law was used to predict their theoretical values. Meanwhile, the proposed CA mode was applied for the simulation of corrosion damage evolution of the CFSSTCs. It was shown by the comparisons of results from the three methods aforementioned that they were in good agreement, implying that the proposed method used for the simulation of corrosion damage evolution of concrete filled steel tubular columns is feasible and effective. It will open a new approach to study and evaluate further the corrosion damage, loading capacity and lifetime prediction of concrete filled steel tubular structures.

  8. Microstructural descriptors and cellular automata simulation of the effects of non-random nuclei location on recrystallization in two dimensions

    Directory of Open Access Journals (Sweden)

    Paulo Rangel Rios

    2006-06-01

    Full Text Available The effect of non-random nuclei location and the efficiency of microstructural descriptors in assessing such a situation are studied. Cellular automata simulation of recrystallization in two dimensions is carried out to simulate microstrutural evolution for nuclei distribution ranging from a periodic arrangement to clusters of nuclei. The simulation results are compared in detail with microstrutural descriptors normally used to follow transformation evolution. It is shown that the contiguity is particularly relevant to detect microstructural deviations from randomness. This work focuses on recrystallization but its results are applicable to any nucleation and growth transformation.

  9. How synapses can enhance sensibility of a neural network

    Science.gov (United States)

    Protachevicz, P. R.; Borges, F. S.; Iarosz, K. C.; Caldas, I. L.; Baptista, M. S.; Viana, R. L.; Lameu, E. L.; Macau, E. E. N.; Batista, A. M.

    2018-02-01

    In this work, we study the dynamic range in a neural network modelled by cellular automaton. We consider deterministic and non-deterministic rules to simulate electrical and chemical synapses. Chemical synapses have an intrinsic time-delay and are susceptible to parameter variations guided by learning Hebbian rules of behaviour. The learning rules are related to neuroplasticity that describes change to the neural connections in the brain. Our results show that chemical synapses can abruptly enhance sensibility of the neural network, a manifestation that can become even more predominant if learning rules of evolution are applied to the chemical synapses.

  10. Coupling biomechanics to a cellular level model: an approach to patient-specific image driven multi-scale and multi-physics tumor simulation.

    Science.gov (United States)

    May, Christian P; Kolokotroni, Eleni; Stamatakos, Georgios S; Büchler, Philippe

    2011-10-01

    Modeling of tumor growth has been performed according to various approaches addressing different biocomplexity levels and spatiotemporal scales. Mathematical treatments range from partial differential equation based diffusion models to rule-based cellular level simulators, aiming at both improving our quantitative understanding of the underlying biological processes and, in the mid- and long term, constructing reliable multi-scale predictive platforms to support patient-individualized treatment planning and optimization. The aim of this paper is to establish a multi-scale and multi-physics approach to tumor modeling taking into account both the cellular and the macroscopic mechanical level. Therefore, an already developed biomodel of clinical tumor growth and response to treatment is self-consistently coupled with a biomechanical model. Results are presented for the free growth case of the imageable component of an initially point-like glioblastoma multiforme tumor. The composite model leads to significant tumor shape corrections that are achieved through the utilization of environmental pressure information and the application of biomechanical principles. Using the ratio of smallest to largest moment of inertia of the tumor material to quantify the effect of our coupled approach, we have found a tumor shape correction of 20% by coupling biomechanics to the cellular simulator as compared to a cellular simulation without preferred growth directions. We conclude that the integration of the two models provides additional morphological insight into realistic tumor growth behavior. Therefore, it might be used for the development of an advanced oncosimulator focusing on tumor types for which morphology plays an important role in surgical and/or radio-therapeutic treatment planning. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. The Neurona at Home project: Simulating a large-scale cellular automata brain in a distributed computing environment

    Science.gov (United States)

    Acedo, L.; Villanueva-Oller, J.; Moraño, J. A.; Villanueva, R.-J.

    2013-01-01

    The Berkeley Open Infrastructure for Network Computing (BOINC) has become the standard open source solution for grid computing in the Internet. Volunteers use their computers to complete an small part of the task assigned by a dedicated server. We have developed a BOINC project called Neurona@Home whose objective is to simulate a cellular automata random network with, at least, one million neurons. We consider a cellular automata version of the integrate-and-fire model in which excitatory and inhibitory nodes can activate or deactivate neighbor nodes according to a set of probabilistic rules. Our aim is to determine the phase diagram of the model and its behaviour and to compare it with the electroencephalographic signals measured in real brains.

  12. Efficiency of timing delays and electrode positions in optimization of biventricular pacing: a simulation study.

    Science.gov (United States)

    Miri, Raz; Graf, Iulia M; Dössel, Olaf

    2009-11-01

    Electrode positions and timing delays influence the efficacy of biventricular pacing (BVP). Accordingly, this study focuses on BVP optimization, using a detailed 3-D electrophysiological model of the human heart, which is adapted to patient-specific anatomy and pathophysiology. The research is effectuated on ten heart models with left bundle branch block and myocardial infarction derived from magnetic resonance and computed tomography data. Cardiac electrical activity is simulated with the ten Tusscher cell model and adaptive cellular automaton at physiological and pathological conduction levels. The optimization methods are based on a comparison between the electrical response of the healthy and diseased heart models, measured in terms of root mean square error (E(RMS)) of the excitation front and the QRS duration error (E(QRS)). Intra- and intermethod associations of the pacing electrodes and timing delays variables were analyzed with statistical methods, i.e., t -test for dependent data, one-way analysis of variance for electrode pairs, and Pearson model for equivalent parameters from the two optimization methods. The results indicate that lateral the left ventricle and the upper or middle septal area are frequently (60% of cases) the optimal positions of the left and right electrodes, respectively. Statistical analysis proves that the two optimization methods are in good agreement. In conclusion, a noninvasive preoperative BVP optimization strategy based on computer simulations can be used to identify the most beneficial patient-specific electrode configuration and timing delays.

  13. Parallel random number generator for inexpensive configurable hardware cells

    Science.gov (United States)

    Ackermann, J.; Tangen, U.; Bödekker, B.; Breyer, J.; Stoll, E.; McCaskill, J. S.

    2001-11-01

    A new random number generator ( RNG) adapted to parallel processors has been created. This RNG can be implemented with inexpensive hardware cells. The correlation between neighboring cells is suppressed with smart connections. With such connection structures, sequences of pseudo-random numbers are produced. Numerical tests including a self-avoiding random walk test and the simulation of the order parameter and energy of the 2D Ising model give no evidence for correlation in the pseudo-random sequences. Because the new random number generator has suppressed the correlation between neighboring cells which is usually observed in cellular automaton implementations, it is applicable for extended time simulations. It gives an immense speed-up factor if implemented directly in configurable hardware, and has recently been used for long time simulations of spatially resolved molecular evolution.

  14. Computer simulation of 2D grain growth using a cellular automata model based on the lowest energy principle

    International Nuclear Information System (INIS)

    He Yizhu; Ding Hanlin; Liu Liufa; Shin, Keesam

    2006-01-01

    The morphology, topology and kinetics of normal grain growth in two-dimension were studied by computer simulation using a cellular automata (Canada) model based on the lowest energy principle. The thermodynamic energy that follows Maxwell-Boltzmann statistics has been introduced into this model for the calculation of energy change. The transition that can reduce the system energy to the lowest level is chosen to occur when there is more than one possible transition direction. The simulation results show that the kinetics of normal grain growth follows the Burke equation with the growth exponent m = 2. The analysis of topology further indicates that normal grain growth can be simulated fairly well by the present CA model. The vanishing of grains with different number of sides is discussed in the simulation

  15. Behaviour of cellular structures with fluid fillers under impact loading

    Directory of Open Access Journals (Sweden)

    Matej Vesenjak

    2007-03-01

    Full Text Available The paper investigates the behaviour of closed- and open-cell cellular structures under uniaxial impact loading by means of computational simulations using the explicit nonlinear finite element code LS-DYNA. Simulations also consider the influence of pore fillers and the base material strain rate sensitivity. The behaviour of closed-cell cellular structure has been evaluated with use of the representative volume element, where the influence of residual gas inside the closed pores has been studied. Open- cell cellular structure was modelled as a whole to properly account for considered fluid flow through the cells, which significantly influences macroscopic behaviour of the cellular structure. The fluid has been modelled by applying a meshless Smoothed Particle Hydrodynamics (SPH method. Parametric computational simulations provide grounds for optimization of cellular structures to satisfy different requirements, which makes them very attractive for use in general engineering applications.

  16. Evaluation tests on controbloc, a programmable automaton for nuclear power plants

    International Nuclear Information System (INIS)

    Pralus, B.; Bourassin, J.L.; Varaldi, G.

    1983-01-01

    Controbloc is the programmable automaton used by Electricite de France (EDF) to equip its 1300 MW range of power plants. EDF and the designer CGEE Alsthom have conducted a large number of tests on prototype series equipment to determine whether it matches its specifications. These tests were performed in various laboratories in the Paris area and were concerned with: (1) verifying performance (acquisition, processing and retrieval cycle times - multiplexed exchange performance); (2) the robustness of equipment and its behaviour in industrial conditions (climatic tests in line with IEC regulations - earthquake resistance in particularly severe conditions - resistance to industrial interference); (3) behaviour when internal faults occur, an aspect of particular importance in view of the role played by Controbloc in nuclear power plants; in the event of a failure, safety (incorrect commands must not be given) and availability (resumption of operation) must be guaranteed. A large number of checks have been carried out both by the designer and EDF, the latter having put into operation an original method which is described in the paper. Controbloc has been thoroughly tested and its modular construction has facilitated the performance of these tests. Some shortcomings have been revealed which the designer or EDF has remedied. (author)

  17. Definition and evolution of quantum cellular automata with two qubits per cell

    International Nuclear Information System (INIS)

    Karafyllidis, Ioannis G.

    2004-01-01

    Studies of quantum computer implementations suggest cellular quantum computer architectures. These architectures can simulate the evolution of quantum cellular automata, which can possibly simulate both quantum and classical physical systems and processes. It is however known that except for the trivial case, unitary evolution of one-dimensional homogeneous quantum cellular automata with one qubit per cell is not possible. Quantum cellular automata that comprise two qubits per cell are defined and their evolution is studied using a quantum computer simulator. The evolution is unitary and its linearity manifests itself as a periodic structure in the probability distribution patterns

  18. Modeling of coupled differential equations for cellular chemical signaling pathways: Implications for assay protocols utilized in cellular engineering.

    Science.gov (United States)

    O'Clock, George D

    2016-08-01

    Cellular engineering involves modification and control of cell properties, and requires an understanding of fundamentals and mechanisms of action for cellular derived product development. One of the keys to success in cellular engineering involves the quality and validity of results obtained from cell chemical signaling pathway assays. The accuracy of the assay data cannot be verified or assured if the effect of positive feedback, nonlinearities, and interrelationships between cell chemical signaling pathway elements are not understood, modeled, and simulated. Nonlinearities and positive feedback in the cell chemical signaling pathway can produce significant aberrations in assay data collection. Simulating the pathway can reveal potential instability problems that will affect assay results. A simulation, using an electrical analog for the coupled differential equations representing each segment of the pathway, provides an excellent tool for assay validation purposes. With this approach, voltages represent pathway enzyme concentrations and operational amplifier feedback resistance and input resistance values determine pathway gain and rate constants. The understanding provided by pathway modeling and simulation is strategically important in order to establish experimental controls for assay protocol structure, time frames specified between assays, and assay concentration variation limits; to ensure accuracy and reproducibility of results.

  19. Cellular-automata supercomputers for fluid-dynamics modeling

    International Nuclear Information System (INIS)

    Margolus, N.; Toffoli, T.; Vichniac, G.

    1986-01-01

    We report recent developments in the modeling of fluid dynamics, and give experimental results (including dynamical exponents) obtained using cellular automata machines. Because of their locality and uniformity, cellular automata lend themselves to an extremely efficient physical realization; with a suitable architecture, an amount of hardware resources comparable to that of a home computer can achieve (in the simulation of cellular automata) the performance of a conventional supercomputer

  20. MIMO Communication for Cellular Networks

    CERN Document Server

    Huang, Howard; Venkatesan, Sivarama

    2012-01-01

    As the theoretical foundations of multiple-antenna techniques evolve and as these multiple-input multiple-output (MIMO) techniques become essential for providing high data rates in wireless systems, there is a growing need to understand the performance limits of MIMO in practical networks. To address this need, MIMO Communication for Cellular Networks presents a systematic description of MIMO technology classes and a framework for MIMO system design that takes into account the essential physical-layer features of practical cellular networks. In contrast to works that focus on the theoretical performance of abstract MIMO channels, MIMO Communication for Cellular Networks emphasizes the practical performance of realistic MIMO systems. A unified set of system simulation results highlights relative performance gains of different MIMO techniques and provides insights into how best to use multiple antennas in cellular networks under various conditions. MIMO Communication for Cellular Networks describes single-user,...

  1. Two Phase Flow Simulation Using Cellular Automata; Simulacion de Flujos de dos Fases con Automatas Celulares

    Energy Technology Data Exchange (ETDEWEB)

    Marcel, C P [Instituto Balseiro, Universidad Nacional de Cuyo, Centro Atomico Bariloche (Argentina)

    2002-07-01

    The classical mathematical treatment of two-phase flows is based on the average of the conservation equations for each phase.In this work, a complementary approach to the modeling of these systems based on statistical population balances of aut omata sets is presented.Automata are entities defined by mathematical states that change following iterative rules representing interactions with the neighborhood.A model of automata for two-phase flow simulation is presented.This model consists of fie lds of virtual spheres that change their volumes and move around a certain environment.The model is more general than the classical cellular automata in two respects: the grid of cellular automata is dismissed in favor of a trajectory generator, and the rules of interaction involve parameters representing the actual physical interactions between phases.Automata simulation was used to study unsolved two-phase flow problems involving high heat flux rates. One system described in this work consists of a vertical channel with saturated water at normal pressure heated from the lower surface.The heater causes water to boil and starts the bubble production.We used cellular automata to describe two-phase flows and the interaction with the heater.General rule s for such cellular automata representing bubbles moving in stagnant liquid were used, with special attention to correct modeling of different mechanisms of heat transfer.The results of the model were compared to previous experiments and correlations finding good agreement.One of the most important findings is the confirmation of Kutateladze's idea about a close relation between the start of critical heat flux and a change in the flow's topology.This was analyzed using a control volume located in the upper surface of the heater.A strong decrease in the interfacial surface just before the CHF start was encountered.The automata describe quite well some characteristic parameters such as the shape of the local void fraction in the

  2. Realistic Simulation of Rice Plant

    Directory of Open Access Journals (Sweden)

    Wei-long DING

    2011-09-01

    Full Text Available The existing research results of virtual modeling of rice plant, however, is far from perfect compared to that of other crops due to its complex structure and growth process. Techniques to visually simulate the architecture of rice plant and its growth process are presented based on the analysis of the morphological characteristics at different stages. Firstly, the simulations of geometrical shape, the bending status and the structural distortion of rice leaves are conducted. Then, by using an improved model for bending deformation, the curved patterns of panicle axis and various types of panicle branches are generated, and the spatial shape of rice panicle is therefore created. Parametric L-system is employed to generate its topological structures, and finite-state automaton is adopted to describe the development of geometrical structures. Finally, the computer visualization of three-dimensional morphologies of rice plant at both organ and individual levels is achieved. The experimental results showed that the proposed methods of modeling the three-dimensional shapes of organs and simulating the growth of rice plant are feasible and effective, and the generated three-dimensional images are realistic.

  3. Individual Subjective Initiative Merge Model Based on Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Yin-Jie Xu

    2013-01-01

    Full Text Available The merge control models proposed for work zones are classified into two types (Hard Control Merge (HCM model and Soft Control Merge (SCM model according to their own control intensity and are compared with a new model, called Individual Subjective Initiative Merge (ISIM model, which is based on the linear lane-changing probability strategy in the merging area. The attention of this paper is paid to the positive impact of the individual subjective initiative for the whole traffic system. Three models (ISIM, HCM, and SCM are established and compared with each other by two order parameters, that is, system output and average vehicle travel time. Finally, numerical results show that both ISIM and SCM perform better than HCM. Compared with SCM, the output of ISIM is 20 vehicles per hour higher under the symmetric input condition and is more stable under the asymmetric input condition. Meanwhile, the average travel time of ISIM is 2000 time steps less under the oversaturated input condition.

  4. An Individual-based Probabilistic Model for Fish Stock Simulation

    Directory of Open Access Journals (Sweden)

    Federico Buti

    2010-08-01

    Full Text Available We define an individual-based probabilistic model of a sole (Solea solea behaviour. The individual model is given in terms of an Extended Probabilistic Discrete Timed Automaton (EPDTA, a new formalism that is introduced in the paper and that is shown to be interpretable as a Markov decision process. A given EPDTA model can be probabilistically model-checked by giving a suitable translation into syntax accepted by existing model-checkers. In order to simulate the dynamics of a given population of soles in different environmental scenarios, an agent-based simulation environment is defined in which each agent implements the behaviour of the given EPDTA model. By varying the probabilities and the characteristic functions embedded in the EPDTA model it is possible to represent different scenarios and to tune the model itself by comparing the results of the simulations with real data about the sole stock in the North Adriatic sea, available from the recent project SoleMon. The simulator is presented and made available for its adaptation to other species.

  5. Genetic Algorithms and Nucleation in VIH-AIDS transition.

    Science.gov (United States)

    Barranon, Armando

    2003-03-01

    VIH to AIDS transition has been modeled via a genetic algorithm that uses boom-boom principle and where population evolution is simulated with a cellular automaton based on SIR model. VIH to AIDS transition is signed by nucleation of infected cells and low probability of infection are obtained for different mutation rates in agreement with clinical results. A power law is obtained with a critical exponent close to the critical exponent of cubic, spherical percolation, colossal magnetic resonance, Ising Model and liquid-gas phase transition in heavy ion collisions. Computations were carried out at UAM-A Supercomputing Lab and author acknowledges financial support from Division of CBI at UAM-A.

  6. Relating timed and register automata

    Directory of Open Access Journals (Sweden)

    Diego Figueira

    2010-11-01

    Full Text Available Timed automata and register automata are well-known models of computation over timed and data words respectively. The former has clocks that allow to test the lapse of time between two events, whilst the latter includes registers that can store data values for later comparison. Although these two models behave in appearance differently, several decision problems have the same (undecidability and complexity results for both models. As a prominent example, emptiness is decidable for alternating automata with one clock or register, both with non-primitive recursive complexity. This is not by chance. This work confirms that there is indeed a tight relationship between the two models. We show that a run of a timed automaton can be simulated by a register automaton, and conversely that a run of a register automaton can be simulated by a timed automaton. Our results allow to transfer complexity and decidability results back and forth between these two kinds of models. We justify the usefulness of these reductions by obtaining new results on register automata.

  7. The cellular environment in computer simulations of radiation-induced damage to DNA

    International Nuclear Information System (INIS)

    Moiseenko, V.V.; Waker, A.J.; Prestwich, W.V.

    1998-01-01

    Radiation-induced DNA single- and double-strand breaks were modeled for 660 keV photon radiation and scavenger capacity mimicking the cellular environment. Atomistic representation of DNA in B form with a first hydration shell was utilized to model direct and indirect damage. Monte Carlo generated electron tracks were used to model energy deposition in matter and to derive initial spatial distributions of species which appear in the medium following radiolysis. Diffusion of species was followed with time, and their reactions with DNA and each other were modeled in an encounter-controlled manner. Three methods to account for hydroxyl radical diffusion in a cellular environment were tested: assumed exponential survival, time-limited modeling and modeling of reactions between hydroxyl radicals and scavengers in an encounter-controlled manner. Although the method based on modeling scavenging in an encounter-controlled manner is more precise, it requires substantially more computer resources than either the exponential or time-limiting method. Scavenger concentrations of 0.5 and 0.15 M were considered using exponential and encounter-controlled methods with reaction rate set at 3 x 10 9 dm 3 mol -1 s -1 . Diffusion length and strand break yields, predicted by these two methods for the same scavenger molarity, were different by 20%-30%. The method based on limiting time of chemistry follow-up to 10 -9 s leads to DNA damage and radical diffusion estimates similar to 0.5 M scavenger concentration in the other two methods. The difference observed in predictions made by the methods considered could be tolerated in computer simulations of DNA damage. (orig.)

  8. The cellular environment in computer simulations of radiation-induced damage to DNA

    International Nuclear Information System (INIS)

    Moiseenko, V.V.; Hamm, R.N.; Waker, A.J.; Prestwich, W.V.

    1988-01-01

    Radiation-induced DNA single- and double-strand breaks were modeled for 660 keV photon radiation and scavenger capacity mimicking the cellular environment. Atomistic representation of DNA in B form with a first hydration shell was utilized to model direct and indirect damage. Monte Carlo generated electron tracks were used to model energy deposition in matter and to derive initial spatial distributions of species which appear in the medium following radiolysis. Diffusion of species was followed with time, and their reactions with DNA and each other were modeled in an encounter-controlled manner. Three methods to account for hydroxyl radical diffusion in cellular environment were tested: assumed exponential survival, time-limited modeling and modeling of reactions between hydroxyl radicals and scavengers in an encounter-controlled manner. Although the method based on modeling scavenging in an encounter-controlled manner is more precise, it requires substantially more computer resources than either the exponential or time-limiting method. Scavenger concentrations of 0.5 and 0.15 M were considered using exponential and encounter-controlled methods with reaction rate set at 3x10 9 dm 3 mol -1 s-1. Diffusion length and strand break yields, predicted by these two methods for the same scavenger molarity, were different by 20%-30%. The method based on limiting time of chemistry follow-up to 10 -9 s leads to DNA damage and radical diffusion estimates similar to 0.5 M scavenger concentration in the other two methods. The difference observed in predictions made by the methods considered could be tolerated in computer simulations of DNA damage. (author)

  9. Study of cellular retention of HMPAO and ECD in a model simulating the blood-brain barrier

    International Nuclear Information System (INIS)

    Ponce, C.; Pittet, N.; Slosman, D.O.

    1997-01-01

    The HMPAO and ECD are two technetium-labelled lipophilic agents clinically used in the imagery of cerebral perfusion. These molecules cross the membranes and are retained inside the cell after being converted to a hydrophilic form. The aim of this study is to establish the distribution of this retention at the level of blood-brain barrier (BBB) and nerve cells. The incorporation of HMPAO or ECD was studied on a model of co-culture simulating the BBB by means of a T84 single-cell layer of tight junction separated from another layer of U373 astrocyte cells. The cell quality and tight junction permeability were evaluated by the cellular retention of 111-indium chloride and by para-cellular diffusion of 14 C mannitol,d-1. The values reported below were obtained at 180 minutes when the radiotracers were added near the 'T84 layer'. The cell quality is validated by the low cellular retention of the indium chloride(2.3±0.3 μg -1 for the T84 cells and 8.2±5.8 μg -1 for the U373 cells). The activity of 14 C mannitol,d-1 diminishes by 23 ± 5 % in the added compartment. The retention of ECD by the U373 cells is significantly higher (20.7 ±4.5 g -1 ) than that of T84 cells (2.9 ± 0.2 μg -1 ). For HMPAO a non-significant tendency could be observed (49 ± 34 μg -1 for the U373 cells and 38 ± 25 μg -1 for the T84 cells)> The results of cellular retention of indium by HMPAO or ECD when added near 'U373 layer' are not significantly different.In conclusion, independently of the side exposed to the radiotracers, one observes an enhanced incorporation of the U373 cells. The ensemble of these results represent additional arguments in favour of a specific cellular incorporation of the radiotracers, independent of the BBB permittivity

  10. The Universe as Automaton From Simplicity and Symmetry to Complexity

    CERN Document Server

    Mainzer, Klaus

    2012-01-01

    This booklet is an essay at the interface of philosophy and complexity research, trying to inspire the reader with new ideas and new conceptual developments of cellular automata.  Going beyond the numerical experiments of Steven Wolfram, it is argued that cellular automata must be considered complex dynamical systems in their own right, requiring appropriate analytical models in order to find precise answers and predictions in the universe of cellular automata.  Indeed, eventually we have to ask whether cellular automata can be considered models of the real world and, conversely, whether there are limits to our modern approach of attributing the world, and the universe for that matter, essentially a digital reality.

  11. Algorithmic Information Dynamics of Persistent Patterns and Colliding Particles in the Game of Life

    KAUST Repository

    Zenil, Hector; Kiani, Narsis A.; Tegner, Jesper

    2018-01-01

    , Conway's Game of Life (GoL) cellular automaton as a case study. We analyze the distribution of prevailing motifs that occur in GoL from the perspective of algorithmic probability. We demonstrate how the tools introduced are an alternative to computable

  12. Evaluation of the dispersion effect in through movement bicycles at signalized intersection via cellular automata simulation

    Science.gov (United States)

    Jiang, Hang; Ma, Yongjian; Jiang, Lin; Chen, Guozhou; Wang, Dongwei

    2018-05-01

    At signalized intersection areas, bicycle traffic presents a dispersion feature which may influence the movements of vehicles during peak period. The primary objective of this study is to simulate the dispersion effect in through-movement bicycle traffic at intersection areas and evaluate its influence on through-movement traffic. A cellular automata (CA) model is developed and validated to simulate the operations of through-movement bicycle traffic departing from two types of intersection approaches. Simulation results show that bicycles benefit from the dispersion effect when they depart from the approach with an exclusive right-turn vehicle lane. But when bicycles travel from the approach with a shared right-turn and through vehicle lane, the dispersion effect will result in friction interference and block interference on through-movement vehicles. Bicycle interferences reduce the vehicle speed and increase the delay of through-movement vehicles. The policy implications in regard to the dispersion effect from two types of approaches are discussed to improve the performance of through-movement traffic operations at signalized intersections.

  13. Numerical Study on Critical Wedge Angle of Cellular Detonation Reflections

    International Nuclear Information System (INIS)

    Gang, Wang; Kai-Xin, Liu; De-Liang, Zhang

    2010-01-01

    The critical wedge angle (CWA) for the transition from regular reflection (RR) to Mach reflection (MR) of a cellular detonation wave is studied numerically by an improved space-time conservation element and solution element method together with a two-step chemical reaction model. The accuracy of that numerical way is verified by simulating cellular detonation reflections at a 19.3° wedge. The planar and cellular detonation reflections over 45°–55° wedges are also simulated. When the cellular detonation wave is over a 50° wedge, numerical results show a new phenomenon that RR and MR occur alternately. The transition process between RR and MR is investigated with the local pressure contours. Numerical analysis shows that the cellular structure is the essential reason for the new phenomenon and the CWA of detonation reflection is not a certain angle but an angle range. (fundamental areas of phenomenology(including applications))

  14. Simulating carbon sequestration using cellular automata and land use assessment for Karaj, Iran

    Science.gov (United States)

    Khatibi, Ali; Pourebrahim, Sharareh; Mokhtar, Mazlin Bin

    2018-06-01

    Carbon sequestration has been proposed as a means of slowing the atmospheric and marine accumulation of greenhouse gases. This study used observed and simulated land use/cover changes to investigate and predict carbon sequestration rates in the city of Karaj. Karaj, a metropolis of Iran, has undergone rapid population expansion and associated changes in recent years, and these changes make it suitable for use as a case study for rapidly expanding urban areas. In particular, high quality agricultural space, green space and gardens have rapidly transformed into industrial, residential and urban service areas. Five classes of land use/cover (residential, agricultural, rangeland, forest and barren areas) were considered in the study; vegetation and soil samples were taken from 20 randomly selected locations. The level of carbon sequestration was determined for the vegetation samples by calculating the amount of organic carbon present using the dry plant weight method, and for soil samples by using the method of Walkley and Black. For each area class, average values of carbon sequestration in vegetation and soil samples were calculated to give a carbon sequestration index. A cellular automata approach was used to simulate changes in the classes. Finally, the carbon sequestration indices were combined with simulation results to calculate changes in carbon sequestration for each class. It is predicted that, in the 15 year period from 2014 to 2029, much agricultural land will be transformed into residential land, resulting in a severe reduction in the level of carbon sequestration. Results from this study indicate that expansion of forest areas in urban counties would be an effective means of increasing the levels of carbon sequestration. Finally, future opportunities to include carbon sequestration into the simulation of land use/cover changes are outlined.

  15. Lunar Dust and Lunar Simulant Activation, Monitoring, Solution and Cellular Toxicity Properties

    Science.gov (United States)

    Wallace, William; Jeevarajan, A. S.

    2009-01-01

    During the Apollo missions, many undesirable situations were encountered that must be mitigated prior to returning humans to the moon. Lunar dust (that part of the lunar regolith less than 20 microns in diameter) was found to produce several problems with mechanical equipment and could have conceivably produced harmful physiological effects for the astronauts. For instance, the abrasive nature of the dust was found to cause malfunctions of various joints and seals of the spacecraft and suits. Additionally, though efforts were made to exclude lunar dust from the cabin of the lunar module, a significant amount of material nonetheless found its way inside. With the loss of gravity correlated with ascent from the lunar surface, much of the finer fraction of this dust began to float and was inhaled by the astronauts. The short visits tothe Moon during Apollo lessened exposure to the dust, but the plan for future lunar stays of up to six months demands that methods be developed to minimize the risk of dust inhalation. The guidelines for what constitutes "safe" exposure will guide the development of engineering controls aimed at preventing the presence of dust in the lunar habitat. This work has shown the effects of grinding on the activation level of lunar dust, the changes in dissolution properties of lunar simulant, and the production of cytokines by cellular systems. Grinding of lunar dust leads to the production of radicals in solution and increased dissolution of lunar simulant in buffers of different pH. Additionally, ground lunar simulant has been shown to promote the production of IL-6 and IL-8, pro-inflammatory cytokines, by alveolar epithelial cells. These results provide evidence of the need for further studies on these materials prior to returning to the lunar surface.

  16. A feasibility study of stateful automaton packet inspection for streaming application detection systems

    Science.gov (United States)

    Tseng, Kuo-Kun; Lo, Jiao; Liu, Yiming; Chang, Shih-Hao; Merabti, Madjid; Ng, Felix, C. K.; Wu, C. H.

    2017-10-01

    The rapid development of the internet has brought huge benefits and social impacts; however, internet security has also become a great problem for users, since traditional approaches to packet classification cannot achieve satisfactory detection performance due to their low accuracy and efficiency. In this paper, a new stateful packet inspection method is introduced, which can be embedded in the network gateway and used by a streaming application detection system. This new detection method leverages the inexact automaton approach, using part of the header field and part of the application layer data of a packet. Based on this approach, an advanced detection system is proposed for streaming applications. The workflow of the system involves two stages: the training stage and the detection stage. In the training stage, the system initially captures characteristic patterns from a set of application packet flows. After this training is completed, the detection stage allows the user to detect the target application by capturing new application flows. This new detection approach is also evaluated using experimental analysis; the results of this analysis show that this new approach not only simplifies the management of the state detection system, but also improves the accuracy of data flow detection, making it feasible for real-world network applications.

  17. Weighted congestion coefficient feedback in intelligent transportation systems

    International Nuclear Information System (INIS)

    Dong Chuanfei; Ma Xu; Wang Binghong

    2010-01-01

    In traffic systems, a reasonable information feedback can improve road capacity. In this Letter, we study dynamics of traffic flow with real-time information. And the influence of a feedback strategy named Weighted Congestion Coefficient Feedback Strategy (WCCFS) is introduced, based on a two-route scenario in which dynamic information can be generated and displayed on the board to guide road users to make a choice. Our model incorporates the effects of adaptability into the cellular automaton models of traffic flow and simulation results adopting this optimal information feedback strategy have demonstrated high efficiency in controlling spatial distribution of traffic patterns compared with the other three information feedback strategies, i.e., vehicle number and flux.

  18. Consistent evolution in a pedestrian flow

    Science.gov (United States)

    Guan, Junbiao; Wang, Kaihua

    2016-03-01

    In this paper, pedestrian evacuation considering different human behaviors is studied by using a cellular automaton (CA) model combined with the snowdrift game theory. The evacuees are divided into two types, i.e. cooperators and defectors, and two different human behaviors, herding behavior and independent behavior, are investigated. It is found from a large amount of numerical simulations that the ratios of the corresponding evacuee clusters are evolved to consistent states despite 11 typically different initial conditions, which may largely owe to self-organization effect. Moreover, an appropriate proportion of initial defectors who are of herding behavior, coupled with an appropriate proportion of initial defectors who are of rationally independent thinking, are two necessary factors for short evacuation time.

  19. Low-momentum track finding in Belle II

    International Nuclear Information System (INIS)

    Lettenbichler, J; Frühwirth, R; Nadler, M; Glattauer, R

    2012-01-01

    The Silicon Vertex Detector (SVD) of the Belle II experiment is a newly developed device with four measurement layers. Track finding in the SVD will be done both in conjunction with the Central Drift Chamber and in stand-alone mode. The reconstruction of very-low-momentum tracks in stand-alone mode is a big challenge, especially in view of the low redundancy and the large expected background. We describe an approach for track finding in this domain, where a cellular automaton and a Kalman filter is combined with a Hopfield network which finds an optimal subset of non-overlapping tracks. We present results on simulated data and evaluate them in terms of efficiency and purity.

  20. Modelling the morphology of migrating bacterial colonies

    Science.gov (United States)

    Nishiyama, A.; Tokihiro, T.; Badoual, M.; Grammaticos, B.

    2010-08-01

    We present a model which aims at describing the morphology of colonies of Proteus mirabilis and Bacillus subtilis. Our model is based on a cellular automaton which is obtained by the adequate discretisation of a diffusion-like equation, describing the migration of the bacteria, to which we have added rules simulating the consolidation process. Our basic assumption, following the findings of the group of Chuo University, is that the migration and consolidation processes are controlled by the local density of the bacteria. We show that it is possible within our model to reproduce the morphological diagrams of both bacteria species. Moreover, we model some detailed experiments done by the Chuo University group, obtaining a fine agreement.

  1. Station Model for Rail Transit System Using Cellular Automata

    International Nuclear Information System (INIS)

    Xun Jing; Ning Bin; Li Keping

    2009-01-01

    In this paper, we propose a new cellular automata model to simulate the railway traffic at station. Based on NaSch model, the proposed station model is composed of the main track and the siding track. Two different schemes for trains passing through station are considered. One is the scheme of 'pass by the main track, start and stop by the siding track'. The other is the scheme of 'two tracks play the same role'. We simulate the train movement using the proposed model and analyze the traffic flow at station. The simulation results demonstrate that the proposed cellular automata model can be successfully used for the simulations of railway traffic. Some characteristic behaviors of railway traffic flow can be reproduced. Moreover, the simulation values of the minimum headway are close to the theoretical values. This result demonstrates the dependability and availability of the proposed model. (general)

  2. Land-Cover Change Analysis and Simulation in Conakry (Guinea, Using Hybrid Cellular-Automata and Markov Model

    Directory of Open Access Journals (Sweden)

    Arafan Traore

    2018-04-01

    Full Text Available In this study, land-cover change in the capital Conakry of Guinea was simulated using the integrated Cellular Automata and Markov model (CA-Markov in the Geographic Information System (GIS and Remote Sensing (RS. Historical land-cover change information was derived from 1986, 2000 and 2016 Landsat data. Using the land-cover change maps of 1986 and 2000, the land-cover change map for 2016 was simulated based on the Markov model in IDRISSI software (Clark University, Worcester, MA, USA. The simulated result was compared with the 2016 land-cover map for validation using the Relative Operating Characteristic (ROC. The ROC result showed a very strong agreement between the two maps. From this result, the land-cover change map for 2025 was simulated using CA-Markov model. The result has indicated that the proportion of the urban area was 49% in 2016, and it is expected to increase to 52% by 2025, while vegetation will decrease from 35% in 2016 to 32% in 2025. This study suggests that the rapid land-cover change has been led by both rapid population growth and extreme poverty in rural areas, which will result in migration into Conakry. The results of this study will provide bases for assessing the sustainability and the management of the urban area and for taking actions to mitigate the degradation of the urban environment.

  3. Combinatorial approaches to evaluate nanodiamond uptake and induced cellular fate

    Science.gov (United States)

    Eldawud, Reem; Reitzig, Manuela; Opitz, Jörg; Rojansakul, Yon; Jiang, Wenjuan; Nangia, Shikha; Zoica Dinu, Cerasela

    2016-02-01

    Nanodiamonds (NDs) are an emerging class of engineered nanomaterials that hold great promise for the next generation of bionanotechnological products to be used for drug and gene delivery, or for bio-imaging and biosensing. Previous studies have shown that upon their cellular uptake, NDs exhibit high biocompatibility in various in vitro and in vivo set-ups. Herein we hypothesized that the increased NDs biocompatibility is a result of minimum membrane perturbations and their reduced ability to induce disruption or damage during cellular translocation. Using multi-scale combinatorial approaches that simulate ND-membrane interactions, we correlated NDs real-time cellular uptake and kinetics with the ND-induced membrane fluctuations to derive energy requirements for the uptake to occur. Our discrete and real-time analyses showed that the majority of NDs internalization occurs within 2 h of cellular exposure, however, with no effects on cellular viability, proliferation or cellular behavior. Furthermore, our simulation analyses using coarse-grained models identified key changes in the energy profile, membrane deformation and recovery time, all functions of the average ND or ND-based agglomerate size. Understanding the mechanisms responsible for ND-cell membrane interactions could possibly advance their implementation in various biomedical applications.

  4. Combinatorial approaches to evaluate nanodiamond uptake and induced cellular fate

    Science.gov (United States)

    Eldawud, Reem; Reitzig, Manuela; Opitz, Jörg; Rojansakul, Yon; Jiang, Wenjuan; Nangia, Shikha; Dinu, Cerasela Zoica

    2016-01-01

    Nanodiamonds (NDs) are an emerging class of engineered nanomaterials that hold great promise for the next generation of bionanotechnological products to be used for drug and gene delivery, or for bio-imaging and biosensing. Previous studies have shown that upon their cellular uptake, NDs exhibit high biocompatibility in various in vitro and in vivo set-ups. Herein we hypothesized that the increased NDs biocompatibility is a result of minimum membrane perturbations and their reduced ability to induce disruption or damage during cellular translocation. Using multi-scale combinatorial approaches that simulate ND-membrane interactions, we correlated NDs real-time cellular uptake and kinetics with the ND-induced membrane fluctuations to derive energy requirements for the uptake to occur. Our discrete and real-time analyses showed that the majority of NDs internalization occurs within 2 h of cellular exposure, however, with no effects on cellular viability, proliferation or cellular behavior. Furthermore, our simulation analyses using coarse-grained models identified key changes in the energy profile, membrane deformation and recovery time, all functions of the average ND or ND-based agglomerate size. Understanding the mechanisms responsible for ND-cell membrane interactions could possibly advance their implementation in various biomedical applications. PMID:26820775

  5. Combinatorial approaches to evaluate nanodiamond uptake and induced cellular fate

    International Nuclear Information System (INIS)

    Eldawud, Reem; Dinu, Cerasela Zoica; Reitzig, Manuela; Opitz, Jörg; Rojansakul, Yon; Jiang, Wenjuan; Nangia, Shikha

    2016-01-01

    Nanodiamonds (NDs) are an emerging class of engineered nanomaterials that hold great promise for the next generation of bionanotechnological products to be used for drug and gene delivery, or for bio-imaging and biosensing. Previous studies have shown that upon their cellular uptake, NDs exhibit high biocompatibility in various in vitro and in vivo set-ups. Herein we hypothesized that the increased NDs biocompatibility is a result of minimum membrane perturbations and their reduced ability to induce disruption or damage during cellular translocation. Using multi-scale combinatorial approaches that simulate ND-membrane interactions, we correlated NDs real-time cellular uptake and kinetics with the ND-induced membrane fluctuations to derive energy requirements for the uptake to occur. Our discrete and real-time analyses showed that the majority of NDs internalization occurs within 2 h of cellular exposure, however, with no effects on cellular viability, proliferation or cellular behavior. Furthermore, our simulation analyses using coarse-grained models identified key changes in the energy profile, membrane deformation and recovery time, all functions of the average ND or ND-based agglomerate size. Understanding the mechanisms responsible for ND-cell membrane interactions could possibly advance their implementation in various biomedical applications. (paper)

  6. Combinatorial approaches to evaluate nanodiamond uptake and induced cellular fate.

    Science.gov (United States)

    Eldawud, Reem; Reitzig, Manuela; Opitz, Jörg; Rojansakul, Yon; Jiang, Wenjuan; Nangia, Shikha; Dinu, Cerasela Zoica

    2016-02-26

    Nanodiamonds (NDs) are an emerging class of engineered nanomaterials that hold great promise for the next generation of bionanotechnological products to be used for drug and gene delivery, or for bio-imaging and biosensing. Previous studies have shown that upon their cellular uptake, NDs exhibit high biocompatibility in various in vitro and in vivo set-ups. Herein we hypothesized that the increased NDs biocompatibility is a result of minimum membrane perturbations and their reduced ability to induce disruption or damage during cellular translocation. Using multi-scale combinatorial approaches that simulate ND-membrane interactions, we correlated NDs real-time cellular uptake and kinetics with the ND-induced membrane fluctuations to derive energy requirements for the uptake to occur. Our discrete and real-time analyses showed that the majority of NDs internalization occurs within 2 h of cellular exposure, however, with no effects on cellular viability, proliferation or cellular behavior. Furthermore, our simulation analyses using coarse-grained models identified key changes in the energy profile, membrane deformation and recovery time, all functions of the average ND or ND-based agglomerate size. Understanding the mechanisms responsible for ND-cell membrane interactions could possibly advance their implementation in various biomedical applications.

  7. Simulation of earthquakes with cellular automata

    Directory of Open Access Journals (Sweden)

    P. G. Akishin

    1998-01-01

    Full Text Available The relation between cellular automata (CA models of earthquakes and the Burridge–Knopoff (BK model is studied. It is shown that the CA proposed by P. Bak and C. Tang,although they have rather realistic power spectra, do not correspond to the BK model. We present a modification of the CA which establishes the correspondence with the BK model.An analytical method of studying the evolution of the BK-like CA is proposed. By this method a functional quadratic in stress release, which can be regarded as an analog of the event energy, is constructed. The distribution of seismic events with respect to this “energy” shows rather realistic behavior, even in two dimensions. Special attention is paid to two-dimensional automata; the physical restrictions on compression and shear stiffnesses are imposed.

  8. Influence of solitons on the transition to spatiotemporal chaos in coupled map lattices

    DEFF Research Database (Denmark)

    Mikkelsen, R.; van Hecke, M.; Bohr, Tomas

    2003-01-01

    We study the transition from laminar to chaotic behavior in deterministic chaotic coupled map lattices and in an extension of the stochastic Domany-Kinzel cellular automaton [E. Domany and W. Kinzel, Phys. Rev. Lett. 53, 311 (1984)]. For the deterministic coupled map lattices, we find evidence th...

  9. Self organized criticality

    International Nuclear Information System (INIS)

    Creutz, M.

    1993-03-01

    Self organized criticality refers to the tendency of highly dissipative systems to drive themselves to a critical state. This has been proposed to explain why observed physics often displays a wide disparity of length and time scales. The phenomenon can be studied in simple cellular automaton models

  10. Reconstruction of DNA sequences using genetic algorithms and cellular automata: towards mutation prediction?

    Science.gov (United States)

    Mizas, Ch; Sirakoulis, G Ch; Mardiris, V; Karafyllidis, I; Glykos, N; Sandaltzopoulos, R

    2008-04-01

    Change of DNA sequence that fuels evolution is, to a certain extent, a deterministic process because mutagenesis does not occur in an absolutely random manner. So far, it has not been possible to decipher the rules that govern DNA sequence evolution due to the extreme complexity of the entire process. In our attempt to approach this issue we focus solely on the mechanisms of mutagenesis and deliberately disregard the role of natural selection. Hence, in this analysis, evolution refers to the accumulation of genetic alterations that originate from mutations and are transmitted through generations without being subjected to natural selection. We have developed a software tool that allows modelling of a DNA sequence as a one-dimensional cellular automaton (CA) with four states per cell which correspond to the four DNA bases, i.e. A, C, T and G. The four states are represented by numbers of the quaternary number system. Moreover, we have developed genetic algorithms (GAs) in order to determine the rules of CA evolution that simulate the DNA evolution process. Linear evolution rules were considered and square matrices were used to represent them. If DNA sequences of different evolution steps are available, our approach allows the determination of the underlying evolution rule(s). Conversely, once the evolution rules are deciphered, our tool may reconstruct the DNA sequence in any previous evolution step for which the exact sequence information was unknown. The developed tool may be used to test various parameters that could influence evolution. We describe a paradigm relying on the assumption that mutagenesis is governed by a near-neighbour-dependent mechanism. Based on the satisfactory performance of our system in the deliberately simplified example, we propose that our approach could offer a starting point for future attempts to understand the mechanisms that govern evolution. The developed software is open-source and has a user-friendly graphical input interface.

  11. Modeling cell adhesion and proliferation: a cellular-automata based approach.

    Science.gov (United States)

    Vivas, J; Garzón-Alvarado, D; Cerrolaza, M

    Cell adhesion is a process that involves the interaction between the cell membrane and another surface, either a cell or a substrate. Unlike experimental tests, computer models can simulate processes and study the result of experiments in a shorter time and lower costs. One of the tools used to simulate biological processes is the cellular automata, which is a dynamic system that is discrete both in space and time. This work describes a computer model based on cellular automata for the adhesion process and cell proliferation to predict the behavior of a cell population in suspension and adhered to a substrate. The values of the simulated system were obtained through experimental tests on fibroblast monolayer cultures. The results allow us to estimate the cells settling time in culture as well as the adhesion and proliferation time. The change in the cells morphology as the adhesion over the contact surface progress was also observed. The formation of the initial link between cell and the substrate of the adhesion was observed after 100 min where the cell on the substrate retains its spherical morphology during the simulation. The cellular automata model developed is, however, a simplified representation of the steps in the adhesion process and the subsequent proliferation. A combined framework of experimental and computational simulation based on cellular automata was proposed to represent the fibroblast adhesion on substrates and changes in a macro-scale observed in the cell during the adhesion process. The approach showed to be simple and efficient.

  12. Packet Payload Monitoring for Internet Worm Content Detection Using Deterministic Finite Automaton with Delayed Dictionary Compression

    Directory of Open Access Journals (Sweden)

    Divya Selvaraj

    2014-01-01

    Full Text Available Packet content scanning is one of the crucial threats to network security and network monitoring applications. In monitoring applications, payload of packets in a network is matched against the set of patterns in order to detect attacks like worms, viruses, and protocol definitions. During network transfer, incoming and outgoing packets are monitored in depth to inspect the packet payload. In this paper, the regular expressions that are basically string patterns are analyzed for packet payloads in detecting worms. Then the grouping scheme for regular expression matching is rewritten using Deterministic Finite Automaton (DFA. DFA achieves better processing speed during regular expression matching. DFA requires more memory space for each state. In order to reduce memory utilization, decompression technique is used. Delayed Dictionary Compression (DDC is applied for achieving better speeds in the communication links. DDC achieves decoding latency during compression of payload packets in the network. Experimental results show that the proposed approach provides better time consumption and memory utilization during detection of Internet worm attacks.

  13. Boundary effects on car accidents in a cellular automaton model

    International Nuclear Information System (INIS)

    Yang Xianqing; Ma Yuqiang; Zhao Yuemin

    2004-01-01

    In this paper we numerically study the probability P ac of occurrence of car accidents in the Nagel-Schreckenberg (NS) model with open boundary condition. In the deterministic NS model, numerical results show that there exists a critical value of extinction rate β above which no car accidents occur, and below which the probability P ac is independent of the speed limit v max and the injection rate α, but only determined by the extinction rate β. In the non-deterministic NS model, the probability P ac is a non-monotonic function of β in the region of low β value, while it is independent of β in the region of high β value. The stochastic braking not only reduces the occurrence of car accidents, but splits degenerate effects of v max on the probability P ac . Theoretical analyses give an agreement with numerical results in the deterministic NS model and in the non-deterministic NS model with v max = 1 in the case of low β value region. Qualitative differences between open and periodic systems in the relations of P ac to the bulk density ρ imply that various correlations may exist between the two systems

  14. Time-based Cellular Automaton track finder for the CBM experiment

    International Nuclear Information System (INIS)

    Akishina, Valentina; Kisel, Ivan

    2015-01-01

    The future heavy-ion experiment CBM (FAIR/GSI, Darmstadt, Germany) will focus on the measurement of rare probes at interaction rates up to 10 MHz with data flow of up to 1 TB/s. The beam will provide free stream of particles without bunch structure. That requires full online event reconstruction and selection not only in space, but also in time, so- called 4D event building and selection. This is a task of the First-Level Event Selection (FLES) package. The FLES reconstruction and selection package consists of several modules: track finding, track fitting, short-lived particles finding, event building and event selection. The input data are distributed within the FLES farm in a form of so-called time-slices, in which time length is proportional to a compute power of a processing node. A time-slice is reconstructed in parallel between cores within a CPU, thus minimising communication between CPUs. After all tracks of the whole time-slice are found and fitted, they are collected into clusters of tracks originated from common primary vertices. After that short-lived particles are found and the full event building process is finished. (paper)

  15. Three-dimensional analysis of cellular microstructures by computer simulation

    International Nuclear Information System (INIS)

    Hanson, K.; Morris, J.W. Jr.

    1977-06-01

    For microstructures of the ''cellular'' type (isotropic growth from a distribution of nuclei which form simultaneously), it is possible to construct an efficient code which will completely analyze the microstructure in three dimensions. Such a computer code for creating and storing the connected graph was constructed

  16. Sharp asymptotics for stochastic dynamics with parallel updating rule

    NARCIS (Netherlands)

    Nardi, F.R.; Spitoni, C.

    2012-01-01

    In this paper we study the metastability problem for a stochastic dynamics with a parallel updating rule; in particular we consider a finite volume Probabilistic Cellular Automaton (PCA) in a small external field at low temperature regime. We are interested in the nucleation of the system, i.e., the

  17. Sharp Asymptotics for Stochastic Dynamics with Parallel Updating Rule

    NARCIS (Netherlands)

    Nardi, F.R.; Spitoni, C.

    2012-01-01

    In this paper we study the metastability problem for a stochastic dynamics with a parallel updating rule; in particular we consider a finite volume Probabilistic Cellular Automaton (PCA) in a small external field at low temperature regime. We are interested in the nucleation of the system, i.e.,

  18. Growth modes of individual ferrite grains in the austenite to ferrite transformation of low carbon steels

    International Nuclear Information System (INIS)

    Li, D.Z.; Xiao, N.M.; Lan, Y.J.; Zheng, C.W.; Li, Y.Y.

    2007-01-01

    The mesoscale deterministic cellular automaton (CA) method and probabilistic Q-state Potts-based Monte Carlo (MC) model have been adopted to investigate independently the individual growth behavior of ferrite grain during the austenite (γ)-ferrite (α) transformation. In these models, the γ-α phase transformation and ferrite grain coarsening induced by α/α grain boundary migration could be simulated simultaneously. The simulations demonstrated that both the hard impingement (ferrite grain coarsening) and the soft impingement (overlapping carbon concentration field) have a great influence on the individual ferrite growth behavior. Generally, ferrite grains displayed six modes of growth behavior: parabolic growth, delayed nucleation and growth, temporary shrinkage, partial shrinkage, complete shrinkage and accelerated growth in the transformation. Some modes have been observed before by the synchrotron X-ray diffraction experiment. The mesoscopic simulation provides an alternative tool for investigating both the individual grain growth behavior and the overall transformation behavior simultaneously during transformation

  19. Application of Digital Cellular Radio for Mobile Location Estimation

    Directory of Open Access Journals (Sweden)

    Farhat Anwar

    2012-08-01

    Full Text Available The capability to locate the position of mobiles is a prerequisite to implement a wide range of evolving ITS services. Radiolocation has the potential to serve a wide geographical area. This paper reports an investigation regarding the feasibility of utilizing cellular radio for the purpose of mobile location estimation. Basic strategies to be utilized for location estimation are elaborated. Two possible approaches for cellular based location estimation are investigated with the help of computer simulation. Their effectiveness and relative merits and demerits are identified. An algorithm specifically adapted for cellular environment is reported with specific features where mobiles, irrespective of their numbers, can locate their position without adversely loading the cellular system.Key Words: ITS, GSM, Cellular Radio, DRGS, GPS.

  20. Water and Sediment Output Evaluation Using Cellular Automata on Alpine Catchment: Soana, Italy - Test Case

    Science.gov (United States)

    Pasculli, Antonio; Audisio, Chiara; Sciarra, Nicola

    2017-12-01

    In the alpine contest, the estimation of the rainfall (inflow) and the discharge (outflow) data are very important in order to, at least, analyse historical time series at catchment scale; determine the hydrological maximum and minimum estimate flood and drought frequency. Hydrological researches become a precious source of information for various human activities, in particular for land use management and planning. Many rainfall- runoff models have been proposed to reflect steady, gradually-varied flow condition inside a catchment. In these last years, the application of Reduced Complexity Models (RCM) has been representing an excellent alternative resource for evaluating the hydrological response of catchments, within a period of time up to decades. Hence, this paper is aimed at the discussion of the application of the research code CAESAR, based on cellular automaton (CA) approach, in order to evaluate the water and the sediment outputs from an alpine catchment (Soana, Italy), selected as test case. The comparison between the predicted numerical results, developed through parametric analysis, and the available measured data are discussed. Finally, the analysis of a numerical estimate of the sediment budget over ten years is presented. The necessity of a fast, but reliable numerical support when the measured data are not so easily accessible, as in Alpine catchments, is highlighted.

  1. Extended Cellular Automata Models of Particles and Space-Time

    Science.gov (United States)

    Beedle, Michael

    2005-04-01

    Models of particles and space-time are explored through simulations and theoretical models that use Extended Cellular Automata models. The expanded Cellular Automata Models consist go beyond simple scalar binary cell-fields, into discrete multi-level group representations like S0(2), SU(2), SU(3), SPIN(3,1). The propagation and evolution of these expanded cellular automatas are then compared to quantum field theories based on the "harmonic paradigm" i.e. built by an infinite number of harmonic oscillators, and with gravitational models.

  2. Design and performance simulation of a segmented-absorber based muon detection system for high energy heavy ion collision experiments

    International Nuclear Information System (INIS)

    Ahmad, S.; Bhaduri, P.P.; Jahan, H.; Senger, A.; Adak, R.; Samanta, S.; Prakash, A.; Dey, K.; Lebedev, A.; Kryshen, E.; Chattopadhyay, S.; Senger, P.; Bhattacharjee, B.; Ghosh, S.K.; Raha, S.; Irfan, M.; Ahmad, N.; Farooq, M.; Singh, B.

    2015-01-01

    A muon detection system (MUCH) based on a novel concept using a segmented and instrumented absorber has been designed for high-energy heavy-ion collision experiments. The system consists of 6 hadron absorber blocks and 6 tracking detector triplets. Behind each absorber block a detector triplet is located which measures the tracks of charged particles traversing the absorber. The performance of such a system has been simulated for the CBM experiment at FAIR (Germany) that is scheduled to start taking data in heavy ion collisions in the beam energy range of 6–45 A GeV from 2019. The muon detection system is mounted downstream to a Silicon Tracking System (STS) that is located in a large aperture dipole magnet which provides momentum information of the charged particle tracks. The reconstructed tracks from the STS are to be matched to the hits measured by the muon detector triplets behind the absorber segments. This method allows the identification of muon tracks over a broad range of momenta including tracks of soft muons which do not pass through all the absorber layers. Pairs of oppositely charged muons identified by MUCH could therefore be combined to measure the invariant masses in a wide range starting from low mass vector mesons (LMVM) up to charmonia. The properties of the absorber (material, thickness, position) and of the tracking chambers (granularity, geometry) have been varied in simulations of heavy-ion collision events generated with the UrQMD generator and propagated through the setup using the GEANT3, the particle transport code. The tracks are reconstructed by a Cellular Automaton algorithm followed by a Kalman Filter. The simulations demonstrate that low mass vector mesons and charmonia can be clearly identified in central Au+Au collisions at beam energies provided by the international Facility for Antiproton and Ion Research (FAIR)

  3. Multi-scale modeling with cellular automata: The complex automata approach

    NARCIS (Netherlands)

    Hoekstra, A.G.; Falcone, J.-L.; Caiazzo, A.; Chopard, B.

    2008-01-01

    Cellular Automata are commonly used to describe complex natural phenomena. In many cases it is required to capture the multi-scale nature of these phenomena. A single Cellular Automata model may not be able to efficiently simulate a wide range of spatial and temporal scales. It is our goal to

  4. Sharp asymptotics for stochastic dynamics with parallel updating rule

    NARCIS (Netherlands)

    Nardi, F.R.; Spitoni, C.

    2012-01-01

    In this paper we study the metastability problem for a stochastic dynamics with a parallel updating rule; in particular we consider a ¿nite volume Probabilistic Cellular Automaton (PCA) in a small external ¿eld at low temperature regime. We are interested in the nucleation of the system, i.e., the

  5. Simulating Complex Systems by Cellular Automata

    CERN Document Server

    Kroc, Jiri; Hoekstra, Alfons G

    2010-01-01

    Deeply rooted in fundamental research in Mathematics and Computer Science, Cellular Automata (CA) are recognized as an intuitive modeling paradigm for Complex Systems. Already very basic CA, with extremely simple micro dynamics such as the Game of Life, show an almost endless display of complex emergent behavior. Conversely, CA can also be designed to produce a desired emergent behavior, using either theoretical methodologies or evolutionary techniques. Meanwhile, beyond the original realm of applications - Physics, Computer Science, and Mathematics – CA have also become work horses in very different disciplines such as epidemiology, immunology, sociology, and finance. In this context of fast and impressive progress, spurred further by the enormous attraction these topics have on students, this book emerges as a welcome overview of the field for its practitioners, as well as a good starting point for detailed study on the graduate and post-graduate level. The book contains three parts, two major parts on th...

  6. Shape evolution of nanostructures by thermal and ion beam processing. Modeling and atomistic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Roentzsch, L.

    2007-07-01

    Single-crystalline nanostructures often exhibit gradients of surface (and/or interface) curvature that emerge from fabrication and growth processes or from thermal fluctuations. Thus, the system-inherent capillary force can initiate morphological transformations during further processing steps or during operation at elevated temperature. Therefore and because of the ongoing miniaturization of functional structures which causes a general rise in surface-to-volume ratios, solid-state capillary phenomena will become increasingly important: On the one hand diffusion-mediated capillary processes can be of practical use in view of non-conventional nanostructure fabrication methods based on self-organization mechanisms, on the other hand they can destroy the integrity of nanostructures which can go along with the failure of functionality. Additionally, capillarity-induced shape transformations are effected and can thereby be controlled by applied fields and forces (guided or driven evolution). With these prospects and challenges at hand, formation and shape transformation of single-crystalline nanostructures due to the system-inherent capillary force in combination with external fields or forces are investigated in the frame of this dissertation by means of atomistic computer simulations. For the exploration (search, description, and prediction) of reaction pathways of nanostructure shape transformations, kinetic Monte Carlo (KMC) simulations are the method of choice. Since the employed KMC code is founded on a cellular automaton principle, the spatio-temporal development of lattice-based N-particle systems (N up to several million) can be followed for time spans of several orders of magnitude, while considering local phenomena due to atomic-scale effects like diffusion, nucleation, dissociation, or ballistic displacements. In this work, the main emphasis is put on nanostructures which have a cylindrical geometry, for example, nanowires (NWs), nanorods, nanotubes etc

  7. Shape evolution of nanostructures by thermal and ion beam processing. Modeling and atomistic simulations

    International Nuclear Information System (INIS)

    Roentzsch, L.

    2007-01-01

    Single-crystalline nanostructures often exhibit gradients of surface (and/or interface) curvature that emerge from fabrication and growth processes or from thermal fluctuations. Thus, the system-inherent capillary force can initiate morphological transformations during further processing steps or during operation at elevated temperature. Therefore and because of the ongoing miniaturization of functional structures which causes a general rise in surface-to-volume ratios, solid-state capillary phenomena will become increasingly important: On the one hand diffusion-mediated capillary processes can be of practical use in view of non-conventional nanostructure fabrication methods based on self-organization mechanisms, on the other hand they can destroy the integrity of nanostructures which can go along with the failure of functionality. Additionally, capillarity-induced shape transformations are effected and can thereby be controlled by applied fields and forces (guided or driven evolution). With these prospects and challenges at hand, formation and shape transformation of single-crystalline nanostructures due to the system-inherent capillary force in combination with external fields or forces are investigated in the frame of this dissertation by means of atomistic computer simulations. For the exploration (search, description, and prediction) of reaction pathways of nanostructure shape transformations, kinetic Monte Carlo (KMC) simulations are the method of choice. Since the employed KMC code is founded on a cellular automaton principle, the spatio-temporal development of lattice-based N-particle systems (N up to several million) can be followed for time spans of several orders of magnitude, while considering local phenomena due to atomic-scale effects like diffusion, nucleation, dissociation, or ballistic displacements. In this work, the main emphasis is put on nanostructures which have a cylindrical geometry, for example, nanowires (NWs), nanorods, nanotubes etc

  8. Cell damage from radiation-induced bystander effects for different cell densities simulated by a mathematical model via cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    Meireles, Sincler P. de; Santos, Adriano M.; Grynberg, Suely Epsztein, E-mail: spm@cdtn.b, E-mail: amsantos@cdtn.b, E-mail: seg@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Nunes, Maria Eugenia S., E-mail: mariaeugenia@iceb.ufop.b [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

    2011-07-01

    During recent years, there has been a shift from an approach focused entirely on DNA as the main target of ionizing radiation to a vision that considers complex signaling pathways in cells and among cells within tissues. Several newly recognized responses were classified as the so-called non-target responses in which the biological effects are not directly related to the amount of energy deposited in the DNA of cells that were traversed by radiation. In 1992 the bystander effect was described referring to a series of responses such as death, chromosomal instability or other abnormalities that occur in non-irradiated cells that came into contact with irradiated cells or medium from irradiated cells. In this work, we have developed a mathematical model via cellular automata, to quantify cell death induced by the bystander effect. The model is based on experiments with irradiated cells conditioned medium which suggests that irradiated cells secrete molecules in the medium that are capable of damaging other cells. The computational model consists of two-dimensional cellular automata which is able to simulate the transmission of bystander signals via extrinsic route and via Gap junctions. The model has been validated by experimental results in the literature. The time evolution of the effect and the dose-response curves were obtained in good accordance to them. Simulations were conducted for different values of bystander and irradiated cell densities with constant dose. From this work, we have obtained a relationship between cell density and effect. (author)

  9. Cell damage from radiation-induced bystander effects for different cell densities simulated by a mathematical model via cellular automata

    International Nuclear Information System (INIS)

    Meireles, Sincler P. de; Santos, Adriano M.; Grynberg, Suely Epsztein; Nunes, Maria Eugenia S.

    2011-01-01

    During recent years, there has been a shift from an approach focused entirely on DNA as the main target of ionizing radiation to a vision that considers complex signaling pathways in cells and among cells within tissues. Several newly recognized responses were classified as the so-called non-target responses in which the biological effects are not directly related to the amount of energy deposited in the DNA of cells that were traversed by radiation. In 1992 the bystander effect was described referring to a series of responses such as death, chromosomal instability or other abnormalities that occur in non-irradiated cells that came into contact with irradiated cells or medium from irradiated cells. In this work, we have developed a mathematical model via cellular automata, to quantify cell death induced by the bystander effect. The model is based on experiments with irradiated cells conditioned medium which suggests that irradiated cells secrete molecules in the medium that are capable of damaging other cells. The computational model consists of two-dimensional cellular automata which is able to simulate the transmission of bystander signals via extrinsic route and via Gap junctions. The model has been validated by experimental results in the literature. The time evolution of the effect and the dose-response curves were obtained in good accordance to them. Simulations were conducted for different values of bystander and irradiated cell densities with constant dose. From this work, we have obtained a relationship between cell density and effect. (author)

  10. AUTO: An Automation Simulator.

    Science.gov (United States)

    Gold, Bennett Alan

    In order to devise an aid for the teaching of formal languages and automata theory, a system was developed which allows a student to design, test, and change automata in an interactive manner. This process permits the user to observe the step-by-step operation of a defined automaton and to correct or alter its operation. Thus, the need for lengthy…

  11. Computer Modeling of the Earliest Cellular Structures and Functions

    Science.gov (United States)

    Pohorille, Andrew; Chipot, Christophe; Schweighofer, Karl

    2000-01-01

    In the absence of extinct or extant record of protocells (the earliest ancestors of contemporary cells). the most direct way to test our understanding of the origin of cellular life is to construct laboratory models of protocells. Such efforts are currently underway in the NASA Astrobiology Program. They are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures and developing designs for molecules that perform proto-cellular functions. Many of these functions, such as import of nutrients, capture and storage of energy. and response to changes in the environment are carried out by proteins bound to membranestructures at water-membrane interfaces and insert into membranes, (b) how these peptides aggregate to form membrane-spanning structures (eg. channels), and (c) by what mechanisms such aggregates perform essential proto-cellular functions, such as proton transport of protons across cell walls, a key step in cellular bioenergetics. The simulations were performed using the molecular dynamics method, in which Newton's equations of motion for each item in the system are solved iteratively. The problems of interest required simulations on multi-nanosecond time scales, which corresponded to 10(exp 6)-10(exp 8) time steps.

  12. Effect of solution treatment conditions on the sensitization of austenitic stainless steel

    Directory of Open Access Journals (Sweden)

    XIAOFEI YU

    2009-11-01

    Full Text Available In this study, the impact of the conditions of solution treatment on the degree of sensitization (DOS of austenitic stainless steel (AISI 304 was investigated in detail. The results derived from the electrochemical potentiodynamic reactivation (EPR test indicated that the DOS decreased as the solution treatment temperature and time increased. The reason for this was studied via the SEM morphologies and EDS results, which indicated that the grain size influenced the DOS. Furthermore, cellular automaton (CA was utilized to simulate grain growth, the precipitation of Cr-rich carbides and the three dimensional distribution of the chromium concentration, which vividly illuminated the effect of the grain size on the DOS and was in accordance with the experiment results.

  13. Corresponding Angle Feedback in an innovative weighted transportation system

    International Nuclear Information System (INIS)

    Dong Chuanfei; Ma Xu

    2010-01-01

    The optimal information feedback has a significant effect on many socioeconomic systems like stock market and traffic systems aiming to make full use of resources. In this Letter, we study dynamics of traffic flow with real-time information. The influence of a feedback strategy named Corresponding Angle Feedback Strategy (CAFS) is introduced, based on a two-route scenario in which dynamic information can be generated and displayed on the board to guide road users to make a choice. Our model incorporates the effects of adaptability into the cellular automaton models of traffic flow and simulation results adopting this optimal information feedback strategy have demonstrated high efficiency in controlling spatial distribution of traffic patterns compared with the other three information feedback strategies, i.e., vehicle number and flux.

  14. Optimizing Cellular Networks Enabled with Renewal Energy via Strategic Learning.

    Science.gov (United States)

    Sohn, Insoo; Liu, Huaping; Ansari, Nirwan

    2015-01-01

    An important issue in the cellular industry is the rising energy cost and carbon footprint due to the rapid expansion of the cellular infrastructure. Greening cellular networks has thus attracted attention. Among the promising green cellular network techniques, the renewable energy-powered cellular network has drawn increasing attention as a critical element towards reducing carbon emissions due to massive energy consumption in the base stations deployed in cellular networks. Game theory is a branch of mathematics that is used to evaluate and optimize systems with multiple players with conflicting objectives and has been successfully used to solve various problems in cellular networks. In this paper, we model the green energy utilization and power consumption optimization problem of a green cellular network as a pilot power selection strategic game and propose a novel distributed algorithm based on a strategic learning method. The simulation results indicate that the proposed algorithm achieves correlated equilibrium of the pilot power selection game, resulting in optimum green energy utilization and power consumption reduction.

  15. Competitive intransitivity promotes species coexistence.

    Science.gov (United States)

    Laird, Robert A; Schamp, Brandon S

    2006-08-01

    Using a spatially explicit cellular automaton model with local competition, we investigate the potential for varied levels of competitive intransitivity (i.e., nonhierarchical competition) to promote species coexistence. As predicted, on average, increased levels of intransitivity result in more sustained coexistence within simulated communities, although the outcome of competition also becomes increasingly unpredictable. Interestingly, even a moderate degree of intransitivity within a community can promote coexistence, in terms of both the length of time until the first competitive exclusion and the number of species remaining in the community after 500 simulated generations. These results suggest that modest levels of intransitivity in nature, such as those that are thought to be characteristic of plant communities, can contribute to coexistence and, therefore, community-scale biodiversity. We explore a potential connection between competitive intransitivity and neutral theory, whereby competitive intransitivity may represent an important mechanism for "ecological equivalence."

  16. Alleviate Cellular Congestion Through Opportunistic Trough Filling

    Directory of Open Access Journals (Sweden)

    Yichuan Wang

    2014-04-01

    Full Text Available The demand for cellular data service has been skyrocketing since the debut of data-intensive smart phones and touchpads. However, not all data are created equal. Many popular applications on mobile devices, such as email synchronization and social network updates, are delay tolerant. In addition, cellular load varies significantly in both large and small time scales. To alleviate network congestion and improve network performance, we present a set of opportunistic trough filling schemes that leverage the time-variation of network congestion and delay-tolerance of certain traffic in this paper. We consider average delay, deadline, and clearance time as the performance metrics. Simulation results show promising performance improvement over the standard schemes. The work shed lights on addressing the pressing issue of cellular overload.

  17. Modeling and Simulation of Polarization in Internet Group Opinions Based on Cellular Automata

    Directory of Open Access Journals (Sweden)

    Yaofeng Zhang

    2015-01-01

    Full Text Available Hot events on Internet always attract many people who usually form one or several opinion camps through discussion. For the problem of polarization in Internet group opinions, we propose a new model based on Cellular Automata by considering neighbors, opinion leaders, and external influences. Simulation results show the following: (1 It is easy to form the polarization for both continuous opinions and discrete opinions when we only consider neighbors influence, and continuous opinions are more effective in speeding the polarization of group. (2 Coevolution mechanism takes more time to make the system stable, and the global coupling mechanism leads the system to consensus. (3 Opinion leaders play an important role in the development of consensus in Internet group opinions. However, both taking the opinion leaders as zealots and taking some randomly selected individuals as zealots are not conductive to the consensus. (4 Double opinion leaders with consistent opinions will accelerate the formation of group consensus, but the opposite opinions will lead to group polarization. (5 Only small external influences can change the evolutionary direction of Internet group opinions.

  18. Heavy vehicle driver workload assessment. Task 7B, in-cab text message system and cellular phone use by heavy vehicle drivers in a part-task driving simulator

    Science.gov (United States)

    This report contains the results of a simulator study conducted to serve as a supplement to a National Highway Traffic Safety Administration (NHTSA) heavy vehicle driver workload field study. Its purpose was the evaluation of effects of cellular phon...

  19. Convolution equations on lattices: periodic solutions with values in a prime characteristic field

    OpenAIRE

    Zaidenberg, Mikhail

    2006-01-01

    These notes are inspired by the theory of cellular automata. A linear cellular automaton on a lattice of finite rank or on a toric grid is a discrete dinamical system generated by a convolution operator with kernel concentrated in the nearest neighborhood of the origin. In the present paper we deal with general convolution operators. We propose an approach via harmonic analysis which works over a field of positive characteristic. It occurs that a standard spectral problem for a convolution op...

  20. A survey on the modeling and applications of cellular automata theory

    Science.gov (United States)

    Gong, Yimin

    2017-09-01

    The Cellular Automata Theory is a discrete model which is now widely used in scientific researches and simulations. The model is comprised of some cells which changes according to a specific rule over time. This paper provides a survey of the Modeling and Applications of Cellular Automata Theory, which focus on the program realization of Cellular Automata Theory and the application of Cellular Automata in each field, such as road traffic, land use, and cutting machines. Each application is further explained, and several related main models are briefly introduced. This research aims to help decision-makers formulate appropriate development plans.

  1. Cellular and Porous Materials Thermal Properties Simulation and Prediction

    CERN Document Server

    Öchsner, Andreas; de Lemos, Marcelo J S

    2008-01-01

    Providing the reader with a solid understanding of the fundamentals as well as an awareness of recent advances in properties and applications of cellular and porous materials, this handbook and ready reference covers all important analytical and numerical methods for characterizing and predicting thermal properties. In so doing it directly addresses the special characteristics of foam-like and hole-riddled materials, combining theoretical and experimental aspects for characterization purposes.

  2. Dual-Level Game-Based Energy Efficiency and Fairness for Green Cellular Networks

    Directory of Open Access Journals (Sweden)

    Sungwook Kim

    2016-01-01

    Full Text Available In the recent decades, cellular networks have revolutionized the way of next generation communication networks. However, due to the global climate change, reducing the energy consumption of cellular infrastructures is an important and urgent problem. In this study, we propose a novel two-level cooperative game framework for improving the energy efficiency and fairness in cellular networks. For the energy efficiency, base stations (BSs constantly monitor the current traffic load and cooperate with each other to maximize the energy saving. For the energy fairness, renewable energy can be shared dynamically while ensuring the fairness among BSs. To achieve an excellent cellular network performance, the concepts of the Raiffa Bargaining Solution and Jain’s fairness are extended and practically applied to our dual-level cooperative game model. Through system level simulations, the proposed scheme is evaluated and compared with other existing schemes. The simulation results show that our two-level game approach outperforms the existing schemes in providing a better fair-efficient system performance.

  3. Three-dimensional detonation cellular structures in rectangular ducts using an improved CESE scheme

    KAUST Repository

    Shen, Yang

    2016-11-01

    The three-dimensional premixed H2-O2 detonation propagation in rectangular ducts is simulated using an in-house parallel detonation code based on the second-order space–time conservation element and solution element (CE/SE) scheme. The simulation reproduces three typical cellular structures by setting appropriate cross-sectional size and initial perturbation in square tubes. As the cross-sectional size decreases, critical cellular structures transforming the rectangular or diagonal mode into the spinning mode are obtained and discussed in the perspective of phase variation as well as decreasing of triple point lines. Furthermore, multiple cellular structures are observed through examples with typical aspect ratios. Utilizing the visualization of detailed three-dimensional structures, their formation mechanism is further analyzed.

  4. Three-dimensional detonation cellular structures in rectangular ducts using an improved CESE scheme

    KAUST Repository

    Shen, Yang; Shen, Hua; Liu, Kai Xin; Chen, Pu; Zhang, De Liang

    2016-01-01

    The three-dimensional premixed H2-O2 detonation propagation in rectangular ducts is simulated using an in-house parallel detonation code based on the second-order space–time conservation element and solution element (CE/SE) scheme. The simulation reproduces three typical cellular structures by setting appropriate cross-sectional size and initial perturbation in square tubes. As the cross-sectional size decreases, critical cellular structures transforming the rectangular or diagonal mode into the spinning mode are obtained and discussed in the perspective of phase variation as well as decreasing of triple point lines. Furthermore, multiple cellular structures are observed through examples with typical aspect ratios. Utilizing the visualization of detailed three-dimensional structures, their formation mechanism is further analyzed.

  5. Myokit: A simple interface to cardiac cellular electrophysiology.

    Science.gov (United States)

    Clerx, Michael; Collins, Pieter; de Lange, Enno; Volders, Paul G A

    2016-01-01

    Myokit is a new powerful and versatile software tool for modeling and simulation of cardiac cellular electrophysiology. Myokit consists of an easy-to-read modeling language, a graphical user interface, single and multi-cell simulation engines and a library of advanced analysis tools accessible through a Python interface. Models can be loaded from Myokit's native file format or imported from CellML. Model export is provided to C, MATLAB, CellML, CUDA and OpenCL. Patch-clamp data can be imported and used to estimate model parameters. In this paper, we review existing tools to simulate the cardiac cellular action potential to find that current tools do not cater specifically to model development and that there is a gap between easy-to-use but limited software and powerful tools that require strong programming skills from their users. We then describe Myokit's capabilities, focusing on its model description language, simulation engines and import/export facilities in detail. Using three examples, we show how Myokit can be used for clinically relevant investigations, multi-model testing and parameter estimation in Markov models, all with minimal programming effort from the user. This way, Myokit bridges a gap between performance, versatility and user-friendliness. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Using Cellular Automata to Investigate Pedestrian Conflicts with Vehicles in Crosswalk at Signalized Intersection

    Directory of Open Access Journals (Sweden)

    Xiaomeng Li

    2012-01-01

    Full Text Available The operational efficiency and safety of pedestrian flows at intersections is an important aspect of urban traffic. Particularly, conflicts between pedestrians and vehicles in crosswalk are one of the most influential factors for intersection safety. This paper presents a cellular automata model that simulates pedestrian and vehicle crossing behaviors at signalized intersections. Through the simulation, we investigate the effects of different pedestrian signal timing and crosswalk widths on the crosswalk capacity, the number of traffic conflicts between pedestrians and vehicles, and pedestrian delay due to the conflicts. The simulation results indicate that the cellular automata is an effective simulation platform for investigating complex pedestrian-related traffic phenomenon at signalized intersections.

  7. A percolation-like model for simulating inter-cellular diffusion in the context of bystander signalling in tumour

    International Nuclear Information System (INIS)

    Moulton, C.R.; Fleming, A.J.; Ebert, M.A.

    2011-01-01

    Full text: Despite ongoing active research, the role of the radiation bystander effect in modifying local tissue response to an ionising radiation dose remains unclear. The present study aims to provide new insight by simulating the diffusion-mediated inter-cellular communication processes in 2D and 3D cell-like structures to calculate likely signal ranges in the diffusion limited case. Random walks of individual signalling molecules were tracked between cells with inclusion of molecule-receptor interactions. The resulting diffusion anomaly is a function of cell density, signal uptake probability and the spatial arrangement of cells local to the signal origin. Uptake probability effects dominate percolation effects in disordered media. Diffu sion through 2D structures is more conducive to anomalous diffusion than diffusion through 3D structures. Values for time-dependent diffusion constants and permeability are derived for typical simulation parameters. Even at low signal uptake probabilities the communication range is restricted to a mean value of less than 100 foun owing to complete signal uptake by 600 s. This should be considered in light of the potential influence of signal relaying, flo dynamics or vasculature-mediated signalling.

  8. The "resident's dilemma"? Values and strategies of medical residents for education interactions: a cellular automata simulation.

    Science.gov (United States)

    Heckerling, P S; Gerber, B S; Weiner, S J

    2006-01-01

    Medical residents engage in formal and informal education interactions with fellow residents during the working day, and can choose whether to spend time and effort on such interactions. Time and effort spent on such interactions can bring learning and personal satisfaction to residents, but may also delay completion of clinical work. Using hypothetical cases, we assessed the values and strategies of internal medicine residents at one hospital for both cooperative and non-cooperative education interactions with fellow residents. We then used these data and cellular automata models of two-person games to simulate repeated interactions between residents, and to determine which strategies resulted in greatest accrued value. We conducted sensitivity analyses on several model parameters, to test the robustness of dominant strategies to model assumptions. Twenty-nine of the 57 residents (50.9%) valued cooperation more than non-cooperation no matter what the other resident did during the current interaction. Similarly, thirty-six residents (63.2%) endorsed an unconditional always-cooperate strategy no matter what the other resident had done during their previous interaction. In simulations, an always-cooperate strategy accrued more value (776.42 value units) than an aggregate of strategies containing non-cooperation components (675.0 value units, p = 0.052). Only when the probability of strategy errors reached 50%, or when values were re-ordered to match those of a Prisoner's Dilemma, did non-cooperation-based strategies accrue the most value. Cooperation-based values and strategies were most frequent among our residents, and dominated in simulations of repeated education interactions between them.

  9. Three-dimensional detonation cellular structures in rectangular ducts using an improved CESE scheme

    International Nuclear Information System (INIS)

    Shen Yang; Liu Kai-Xin; Chen Pu; Shen Hua; Zhang De-Liang

    2016-01-01

    The three-dimensional premixed H 2 -O 2 detonation propagation in rectangular ducts is simulated using an in-house parallel detonation code based on the second-order space–time conservation element and solution element (CE/SE) scheme. The simulation reproduces three typical cellular structures by setting appropriate cross-sectional size and initial perturbation in square tubes. As the cross-sectional size decreases, critical cellular structures transforming the rectangular or diagonal mode into the spinning mode are obtained and discussed in the perspective of phase variation as well as decreasing of triple point lines. Furthermore, multiple cellular structures are observed through examples with typical aspect ratios. Utilizing the visualization of detailed three-dimensional structures, their formation mechanism is further analyzed. (paper)

  10. Porting and optimizing MAGFLOW on CUDA

    Directory of Open Access Journals (Sweden)

    Ciro Del Negro

    2011-12-01

    Full Text Available The MAGFLOW lava simulation model is a cellular automaton developed by the Sezione di Catania of the Istituto Nazionale di Geofisica e Vulcanologia (INGV and it represents the peak of the evolution of cell-based models for lava-flow simulation. The accuracy and adherence to reality achieved by the physics-based cell evolution of MAGFLOW comes at the cost of significant computational times for long-running simulations. The present study describes the efforts and results obtained by porting the original serial code to the parallel computational platforms offered by modern video cards, and in particular to the NVIDIA Compute Unified Device Architecture (CUDA. A number of optimization strategies that have been used to achieve optimal performance on a graphic processing units (GPU are also discussed. The actual benefits of running on the GPU rather than the central processing unit depends on the extent and duration of the simulated event; for large, long-running simulations, the GPU can be 70-to-80-times faster, while for short-lived eruptions with a small extents the speed improvements obtained are 40-to-50 times.

  11. Automata, universality, computation tribute to Maurice Margenstern

    CERN Document Server

    2015-01-01

    This book is an intellectually stimulating excursion into mathematical machines and structures capable for a universal computation. World top experts in computer science and mathematics overview exciting and intriguing topics of logical theory of monoids, geometry of Gauss word, philosophy of mathematics in computer science, asynchronous and parallel P-systems, decidability in cellular automata, splicing systems, reversible Turing machines, information flows in two-way finite automata, prime generators in automaton arrays, Grossone and Turing machines, automaton models of atomic lattices. The book is  full of visually attractive examples of mathematical machines, open problems and challenges for future research. Those interested in the advancement of a theory of computation, philosophy of mathematics, future and emergent computing paradigms, architectures and implementations will find the book vital for their research and development.

  12. Dynamic data-driven integrated flare model based on self-organized criticality

    Science.gov (United States)

    Dimitropoulou, M.; Isliker, H.; Vlahos, L.; Georgoulis, M. K.

    2013-05-01

    with observations. Peak and total flare energy obey single power laws with indices -1.65 ± 0.11 and -1.47 ± 0.13, while the flare duration is best fitted with a double power law (-2.15 ± 0.15 and -3.60 ± 0.09 for the flatter and steeper parts, respectively). Conclusions: We conclude that well-known statistical properties of flares are reproduced after active regions reach the state of self-organized criticality. A significant enhancement of our refined cellular automaton model is that it initiates and further drives the simulation from observed evolving vector magnetograms, thus facilitating energy calculation in physical units, while a separation between MHD and kinetic timescales is possible by assigning distinct MHD timestamps to each interpolation step.

  13. Design Optimization of Irregular Cellular Structure for Additive Manufacturing

    Science.gov (United States)

    Song, Guo-Hua; Jing, Shi-Kai; Zhao, Fang-Lei; Wang, Ye-Dong; Xing, Hao; Zhou, Jing-Tao

    2017-09-01

    Irregularcellular structurehas great potential to be considered in light-weight design field. However, the research on optimizing irregular cellular structures has not yet been reporteddue to the difficulties in their modeling technology. Based on the variable density topology optimization theory, an efficient method for optimizing the topology of irregular cellular structures fabricated through additive manufacturing processes is proposed. The proposed method utilizes tangent circles to automatically generate the main outline of irregular cellular structure. The topological layoutof each cellstructure is optimized using the relative density informationobtained from the proposed modified SIMP method. A mapping relationship between cell structure and relative densityelement is builtto determine the diameter of each cell structure. The results show that the irregular cellular structure can be optimized with the proposed method. The results of simulation and experimental test are similar for irregular cellular structure, which indicate that the maximum deformation value obtained using the modified Solid Isotropic Microstructures with Penalization (SIMP) approach is lower 5.4×10-5 mm than that using the SIMP approach under the same under the same external load. The proposed research provides the instruction to design the other irregular cellular structure.

  14. Agent-Based Modeling of Mitochondria Links Sub-Cellular Dynamics to Cellular Homeostasis and Heterogeneity.

    Directory of Open Access Journals (Sweden)

    Giovanni Dalmasso

    Full Text Available Mitochondria are semi-autonomous organelles that supply energy for cellular biochemistry through oxidative phosphorylation. Within a cell, hundreds of mobile mitochondria undergo fusion and fission events to form a dynamic network. These morphological and mobility dynamics are essential for maintaining mitochondrial functional homeostasis, and alterations both impact and reflect cellular stress states. Mitochondrial homeostasis is further dependent on production (biogenesis and the removal of damaged mitochondria by selective autophagy (mitophagy. While mitochondrial function, dynamics, biogenesis and mitophagy are highly-integrated processes, it is not fully understood how systemic control in the cell is established to maintain homeostasis, or respond to bioenergetic demands. Here we used agent-based modeling (ABM to integrate molecular and imaging knowledge sets, and simulate population dynamics of mitochondria and their response to environmental energy demand. Using high-dimensional parameter searches we integrated experimentally-measured rates of mitochondrial biogenesis and mitophagy, and using sensitivity analysis we identified parameter influences on population homeostasis. By studying the dynamics of cellular subpopulations with distinct mitochondrial masses, our approach uncovered system properties of mitochondrial populations: (1 mitochondrial fusion and fission activities rapidly establish mitochondrial sub-population homeostasis, and total cellular levels of mitochondria alter fusion and fission activities and subpopulation distributions; (2 restricting the directionality of mitochondrial mobility does not alter morphology subpopulation distributions, but increases network transmission dynamics; and (3 maintaining mitochondrial mass homeostasis and responding to bioenergetic stress requires the integration of mitochondrial dynamics with the cellular bioenergetic state. Finally, (4 our model suggests sources of, and stress conditions

  15. Excellent approach to modeling urban expansion by fuzzy cellular automata: agent base model

    Science.gov (United States)

    Khajavigodellou, Yousef; Alesheikh, Ali A.; Mohammed, Abdulrazak A. S.; Chapi, Kamran

    2014-09-01

    Recently, the interaction between humans and their environment is the one of important challenges in the world. Landuse/ cover change (LUCC) is a complex process that includes actors and factors at different social and spatial levels. The complexity and dynamics of urban systems make the applicable practice of urban modeling very difficult. With the increased computational power and the greater availability of spatial data, micro-simulation such as the agent based and cellular automata simulation methods, has been developed by geographers, planners, and scholars, and it has shown great potential for representing and simulating the complexity of the dynamic processes involved in urban growth and land use change. This paper presents Fuzzy Cellular Automata in Geospatial Information System and remote Sensing to simulated and predicted urban expansion pattern. These FCA-based dynamic spatial urban models provide an improved ability to forecast and assess future urban growth and to create planning scenarios, allowing us to explore the potential impacts of simulations that correspond to urban planning and management policies. A fuzzy inference guided cellular automata approach. Semantic or linguistic knowledge on Land use change is expressed as fuzzy rules, based on which fuzzy inference is applied to determine the urban development potential for each pixel. The model integrates an ABM (agent-based model) and FCA (Fuzzy Cellular Automata) to investigate a complex decision-making process and future urban dynamic processes. Based on this model rapid development and green land protection under the influences of the behaviors and decision modes of regional authority agents, real estate developer agents, resident agents and non- resident agents and their interactions have been applied to predict the future development patterns of the Erbil metropolitan region.

  16. Using cellular automata to simulate forest fire propagation in Portugal

    Science.gov (United States)

    Freire, Joana; daCamara, Carlos

    2017-04-01

    Wildfires in the Mediterranean region have severe damaging effects mainly due to large fire events [1, 2]. When restricting to Portugal, wildfires have burned over 1:4 million ha in the last decade. Considering the increasing tendency in the extent and severity of wildfires [1, 2], the availability of modeling tools of fire episodes is of crucial importance. Two main types of mathematical models are generally available, namely deterministic and stochastic models. Deterministic models attempt a description of fires, fuel and atmosphere as multiphase continua prescribing mass, momentum and energy conservation, which typically leads to systems of coupled PDEs to be solved numerically on a grid. Simpler descriptions, such as FARSITE, neglect the interaction with atmosphere and propagate the fire front using wave techniques. One of the most important stochastic models are Cellular Automata (CA), in which space is discretized into cells, and physical quantities take on a finite set of values at each cell. The cells evolve in discrete time according to a set of transition rules, and the states of the neighboring cells. In the present work, we implement and then improve a simple and fast CA model designed to operationally simulate wildfires in Portugal. The reference CA model chosen [3] has the advantage of having been applied successfully in other Mediterranean ecosystems, namely to historical fires in Greece. The model is defined on a square grid with propagation to 8 nearest and next-nearest neighbors, where each cell is characterized by 4 possible discrete states, corresponding to burning, not-yet burned, fuel-free and completely burned cells, with 4 possible rules of evolution which take into account fuel properties, meteorological conditions, and topography. As a CA model, it offers the possibility to run a very high number of simulations in order to verify and apply the model, and is easily modified by implementing additional variables and different rules for the

  17. Cellular modelling of river catchments and reaches: Advantages, limitations and prospects

    Science.gov (United States)

    Coulthard, T. J.; Hicks, D. M.; Van De Wiel, M. J.

    2007-10-01

    The last decade has witnessed the development of a series of cellular models that simulate the processes operating within river channels and drive their geomorphic evolution. Their proliferation can be partly attributed to the relative simplicity of cellular models and their ability to address some of the shortcomings of other numerical models. By using relaxed interpretations of the equations determining fluid flow, cellular models allow rapid solutions of water depths and velocities. These can then be used to drive (usually) conventional sediment transport relations to determine erosion and deposition and alter the channel form. The key advance of using these physically based yet simplified approaches is that they allow us to apply models to a range of spatial scales (1-100 km 2) and time periods (1-100 years) that are especially relevant to contemporary management and fluvial studies. However, these approaches are not without their limitations and technical problems. This paper reviews the findings of nearly 10 years of research into modelling fluvial systems with cellular techniques, principally focusing on improvements in routing water and how fluvial erosion and deposition (including lateral erosion) are represented. These ideas are illustrated using sample simulations of the River Teifi, Wales. A detailed case study is then presented, demonstrating how cellular models can explore the interactions between vegetation and the morphological dynamics of the braided Waitaki River, New Zealand. Finally, difficulties associated with model validation and the problems, prospects and future issues important to the further development and application of these cellular fluvial models are outlined.

  18. Cellular automata with voting rule

    International Nuclear Information System (INIS)

    Makowiec, D.

    1996-01-01

    The chosen local interaction - the voting (majority) rule applied to the square lattice is known to cause the non ergodic cellular automata behaviour. Presented computer simulation results verify two cases of non ergodicity. The first one is implicated by the noise introduced to the local interactions and the second one follows properties of the initial lattice configuration selected at random. For the simplified voting rule - non symmetric voting, the critical behaviour has been explained rigorously. (author)

  19. Cellular structure of lean hydrogen flames in microgravity

    Science.gov (United States)

    Patnaik, G.; Kailasanath, K.

    1990-01-01

    Detailed, time-dependent, two-dimensional numerical simulations of premixed laminar flames have been used to study the initiation and subsequent development of cellular structures in lean hydrogen-air flames. The model includes detailed hydrogen-oxygen combustion with 24 elementary reactions of eight reactive species and a nitrogen diluent, molecular diffusion of all species, thermal conduction, viscosity, and convection. This model has been used to study the nonlinear evolution of cellular flame structure and shows that cell splitting, as observed in experiments, can be predicted numerically for sufficiently reactive mixtures. The structures that evolved also resembled the cellular structures observed in experiments. The present study shows that the 'cell-split limit' postulated from experimental observations is an intrinsic property of the mixture and that external factors such as heat losses are not necessary to cause this limit.

  20. A new micromechanical approach of micropolar continuum modeling for 2-D periodic cellular material

    Institute of Scientific and Technical Information of China (English)

    Bin Niu; Jun Yan

    2016-01-01

    In this paper, we present a new united approach to formulate the equivalent micropolar constitutive relation of two-dimensional (2-D) periodic cellular material to capture its non-local properties and to explain the size effects in its structural analysis. The new united approach takes both the displacement compatibility and the equilibrium of forces and moments into consideration, where Taylor series expansion of the displacement and rotation fields and the extended aver-aging procedure with an explicit enforcement of equilibrium are adopted in the micromechanical analysis of a unit cell. In numerical examples, the effective micropolar constants obtained in this paper and others derived in the literature are used for the equivalent micropolar continuum simulation of cellular solids. The solutions from the equivalent analysis are compared with the discrete simulation solutions of the cellu-lar solids. It is found that the micropolar constants developed in this paper give satisfying results of equivalent analysis for the periodic cellular material.

  1. Multiscale simulation of molecular processes in cellular environments.

    Science.gov (United States)

    Chiricotto, Mara; Sterpone, Fabio; Derreumaux, Philippe; Melchionna, Simone

    2016-11-13

    We describe the recent advances in studying biological systems via multiscale simulations. Our scheme is based on a coarse-grained representation of the macromolecules and a mesoscopic description of the solvent. The dual technique handles particles, the aqueous solvent and their mutual exchange of forces resulting in a stable and accurate methodology allowing biosystems of unprecedented size to be simulated.This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'. © 2016 The Author(s).

  2. Cellular neural networks (CNN) simulation for the TN approximation of the time dependent neutron transport equation in slab geometry

    International Nuclear Information System (INIS)

    Hadad, Kamal; Pirouzmand, Ahmad; Ayoobian, Navid

    2008-01-01

    This paper describes the application of a multilayer cellular neural network (CNN) to model and solve the time dependent one-speed neutron transport equation in slab geometry. We use a neutron angular flux in terms of the Chebyshev polynomials (T N ) of the first kind and then we attempt to implement the equations in an equivalent electrical circuit. We apply this equivalent circuit to analyze the T N moments equation in a uniform finite slab using Marshak type vacuum boundary condition. The validity of the CNN results is evaluated with numerical solution of the steady state T N moments equations by MATLAB. Steady state, as well as transient simulations, shows a very good comparison between the two methods. We used our CNN model to simulate space-time response of total flux and its moments for various c (where c is the mean number of secondary neutrons per collision). The complete algorithm could be implemented using very large-scale integrated circuit (VLSI) circuitry. The efficiency of the calculation method makes it useful for neutron transport calculations

  3. Visual language recognition with a feed-forward network of spiking neurons

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Craig E [Los Alamos National Laboratory; Garrett, Kenyan [Los Alamos National Laboratory; Sottile, Matthew [GALOIS; Shreyas, Ns [INDIANA UNIV.

    2010-01-01

    An analogy is made and exploited between the recognition of visual objects and language parsing. A subset of regular languages is used to define a one-dimensional 'visual' language, in which the words are translational and scale invariant. This allows an exploration of the viewpoint invariant languages that can be solved by a network of concurrent, hierarchically connected processors. A language family is defined that is hierarchically tiling system recognizable (HREC). As inspired by nature, an algorithm is presented that constructs a cellular automaton that recognizes strings from a language in the HREC family. It is demonstrated how a language recognizer can be implemented from the cellular automaton using a feed-forward network of spiking neurons. This parser recognizes fixed-length strings from the language in parallel and as the computation is pipelined, a new string can be parsed in each new interval of time. The analogy with formal language theory allows inferences to be drawn regarding what class of objects can be recognized by visual cortex operating in purely feed-forward fashion and what class of objects requires a more complicated network architecture.

  4. Modeling integrated cellular machinery using hybrid Petri-Boolean networks.

    Directory of Open Access Journals (Sweden)

    Natalie Berestovsky

    Full Text Available The behavior and phenotypic changes of cells are governed by a cellular circuitry that represents a set of biochemical reactions. Based on biological functions, this circuitry is divided into three types of networks, each encoding for a major biological process: signal transduction, transcription regulation, and metabolism. This division has generally enabled taming computational complexity dealing with the entire system, allowed for using modeling techniques that are specific to each of the components, and achieved separation of the different time scales at which reactions in each of the three networks occur. Nonetheless, with this division comes loss of information and power needed to elucidate certain cellular phenomena. Within the cell, these three types of networks work in tandem, and each produces signals and/or substances that are used by the others to process information and operate normally. Therefore, computational techniques for modeling integrated cellular machinery are needed. In this work, we propose an integrated hybrid model (IHM that combines Petri nets and Boolean networks to model integrated cellular networks. Coupled with a stochastic simulation mechanism, the model simulates the dynamics of the integrated network, and can be perturbed to generate testable hypotheses. Our model is qualitative and is mostly built upon knowledge from the literature and requires fine-tuning of very few parameters. We validated our model on two systems: the transcriptional regulation of glucose metabolism in human cells, and cellular osmoregulation in S. cerevisiae. The model produced results that are in very good agreement with experimental data, and produces valid hypotheses. The abstract nature of our model and the ease of its construction makes it a very good candidate for modeling integrated networks from qualitative data. The results it produces can guide the practitioner to zoom into components and interconnections and investigate them

  5. Parallel Genetic Algorithms for calibrating Cellular Automata models: Application to lava flows

    International Nuclear Information System (INIS)

    D'Ambrosio, D.; Spataro, W.; Di Gregorio, S.; Calabria Univ., Cosenza; Crisci, G.M.; Rongo, R.; Calabria Univ., Cosenza

    2005-01-01

    Cellular Automata are highly nonlinear dynamical systems which are suitable far simulating natural phenomena whose behaviour may be specified in terms of local interactions. The Cellular Automata model SCIARA, developed far the simulation of lava flows, demonstrated to be able to reproduce the behaviour of Etnean events. However, in order to apply the model far the prediction of future scenarios, a thorough calibrating phase is required. This work presents the application of Genetic Algorithms, general-purpose search algorithms inspired to natural selection and genetics, far the parameters optimisation of the model SCIARA. Difficulties due to the elevated computational time suggested the adoption a Master-Slave Parallel Genetic Algorithm far the calibration of the model with respect to the 2001 Mt. Etna eruption. Results demonstrated the usefulness of the approach, both in terms of computing time and quality of performed simulations

  6. Simulation of land use change and effect on potential deforestation using Markov Chain - Cellular Automata

    Science.gov (United States)

    Mujiono, Indra, T. L.; Harmantyo, D.; Rukmana, I. P.; Nadia, Z.

    2017-07-01

    The purpose of this study was to simulate land use change in 1996-2016 and its prediction in 2035 as well as its potential to deforestation. Both of these purposes were obtained through modeling analysis using Markov Chain Cellular Automata. This modeling method was considered important for understanding the causes and impacts. Based on the analysis, the land use change between 1996 to 2007 has caused forest loss (the region and non-region) covering an area of 62,012 ha. While in the period of 2007 to 2016, the change has lead to the east side of the slope grade of 0-15 percent and an altitude between 500-1000 meters above sea level. In this period, plantation area has increased by 50,822 ha, while the forest area has reduced from 80,038 ha. In a period of 20 years, North Bengkulu Regency has lost the forest area of 80,038 ha. The amount of intervention against forest suggested the potential for deforestation in this area. Simulation of land use change in 2035 did not indicate significant deforestation due to the limited land on physical factors such as slope and elevation. However, it should be noted that, in 2035, the area of conservation forest was reduced by 16,793 ha (29 %), while the areas of protected and production forest were reduced by 4,933 ha (19 %) and 2,114 ha (3 %), respectively. Land use change is a serious threat of deforestation, especially in forest areas in North Bengkulu Regency, where any decline in forest area means the addition of plantation area.

  7. Application of CA and NN for event recognition in experiments DISTO and STREAMER

    International Nuclear Information System (INIS)

    Bussa, M.P.; Ivanov, V.V.; Kisel, I.V.; Pontecorvo, G.B.

    1997-01-01

    An algorithm for charged particle recognition and event identification applying a cellular automaton (CA) model and a multi-layer neural network (NN) has been developed for the DISTO experiment under way at Saturne (Saclay, France). A further development of the model will be applied for particle recognition in the Dubna Streamer Chamber Spectrometer (DSCS) for studying pion-nucleus absorption (experiments DISTO and STREAMER). (orig.)

  8. Influence of Secondary Cooling Mode on Solidification Structure and Macro-segregation Behavior for High-carbon Continuous Casting Bloom

    Science.gov (United States)

    Dou, Kun; Yang, Zhenguo; Liu, Qing; Huang, Yunhua; Dong, Hongbiao

    2017-07-01

    A cellular automaton-finite element coupling model for high-carbon continuously cast bloom of GCr15 steel is established to simulate the solidification structure and to investigate the influence of different secondary cooling modes on characteristic parameters such as equiaxed crystal ratio, grain size and secondary dendrite arm spacing, in which the effect of phase transformation and electromagnetic stirring is taken into consideration. On this basis, evolution of carbon macro-segregation for GCr15 steel bloom is researched correspondingly via industrial tests. Based on above analysis, the relationship among secondary cooling modes, characteristic parameters for solidification structure as well as carbon macro-segregation is illustrated to obtain optimum secondary cooling strategy and alleviate carbon macro-segregation degree for GCr15 steel bloom in continuous casting process. The evaluating method for element macro-segregation is applicable in various steel types.

  9. Track reconstruction at the ILC: the ILD tracking software

    International Nuclear Information System (INIS)

    Gaede, Frank; Aplin, Steven; Rosemann, Christoph; Voutsinas, Georgios; Glattauer, Robin

    2014-01-01

    One of the key requirements for Higgs physics at the International Linear Collider ILC is excellent track reconstruction with very good momentum and impact parameter resolution. ILD is one of the two detector concepts at the ILC. Its central tracking system comprises of an outer Si-tracker, a highly granular TPC, an intermediate silicon tracker and a pixel vertex detector, and it is complemented by silicon tracking disks in the forward direction. Large hit densities from beam induced coherent electron-positron pairs at the ILC pose an additional challenge to the pattern recognition algorithms. We present the recently developed new ILD tracking software, the pattern recognition algorithms that are using clustering techniques, Cellular Automatons and Kalman filter based track extrapolation. The performance of the ILD tracking system is evaluated using a detailed simulation including dead material, gaps and imperfections.

  10. Initial value sensitivity of the Chinese stock market and its relationship with the investment psychology

    Science.gov (United States)

    Ying, Shangjun; Li, Xiaojun; Zhong, Xiuqin

    2015-04-01

    This paper discusses the initial value sensitivity (IVS) of Chinese stock market, including the single stock market and the Chinese A-share stock market, with respect to real markets and evolving models. The aim is to explore the relationship between IVS of the Chinese A-share stock market and the investment psychology based on the evolving model of genetic cellular automaton (GCA). We find: (1) The Chinese stock market is sensitively dependent on the initial conditions. (2) The GCA model provides a considerable reliability in complexity simulation (e.g. the IVS). (3) The IVS of stock market is positively correlated with the imitation probability when the intensity of the imitation psychology reaches a certain threshold. The paper suggests that the government should seek to keep the imitation psychology under a certain level, otherwise it may induce severe fluctuation to the market.

  11. Quantum Nano-Automata (QNA) : Towards Microphysical Measurements with Quantum, Nanoscale 'Instruments'

    CERN Document Server

    Baianu, IC

    2004-01-01

    Two important concepts for nanoscience and nanotechnology-- the quantum automaton and quantum computation--were introduced in the context of quantum genetics and complex genetic networks with nonlinear dynamics. In previous publications (Baianu,1971a, b) the formal definition of quantum automaton was initially presented in the Schrodinger representation of quantum mechanics, and several possible implications for genetic processes and metabolic activities in living cells and organisms were considered. This was followed by reports on quantum, as well as symbolic, abstract computations based on the theory of categories, functors and natural transformations (Baianu,1971b; 1977; 1987; 2004; Baianu et al, 2004). The notions of quantum topological semigroup, quantum automaton, and/or quantum computer, were then suggested with a view to their potential applications to the analogous simulation of biological systems, and especially genetic activities and nonlinear dynamics in genetic networks. A representation of inter...

  12. Towards self-correcting quantum memories

    Science.gov (United States)

    Michnicki, Kamil

    This thesis presents a model of self-correcting quantum memories where quantum states are encoded using topological stabilizer codes and error correction is done using local measurements and local dynamics. Quantum noise poses a practical barrier to developing quantum memories. This thesis explores two types of models for suppressing noise. One model suppresses thermalizing noise energetically by engineering a Hamiltonian with a high energy barrier between code states. Thermalizing dynamics are modeled phenomenologically as a Markovian quantum master equation with only local generators. The second model suppresses stochastic noise with a cellular automaton that performs error correction using syndrome measurements and a local update rule. Several ways of visualizing and thinking about stabilizer codes are presented in order to design ones that have a high energy barrier: the non-local Ising model, the quasi-particle graph and the theory of welded stabilizer codes. I develop the theory of welded stabilizer codes and use it to construct a code with the highest known energy barrier in 3-d for spin Hamiltonians: the welded solid code. Although the welded solid code is not fully self correcting, it has some self correcting properties. It has an increased memory lifetime for an increased system size up to a temperature dependent maximum. One strategy for increasing the energy barrier is by mediating an interaction with an external system. I prove a no-go theorem for a class of Hamiltonians where the interaction terms are local, of bounded strength and commute with the stabilizer group. Under these conditions the energy barrier can only be increased by a multiplicative constant. I develop cellular automaton to do error correction on a state encoded using the toric code. The numerical evidence indicates that while there is no threshold, the model can extend the memory lifetime significantly. While of less theoretical importance, this could be practical for real

  13. Spatiotemporal Simulation of Tourist Town Growth Based on the Cellular Automata Model: The Case of Sanpo Town in Hebei Province

    Directory of Open Access Journals (Sweden)

    Jun Yang

    2013-01-01

    Full Text Available Spatiotemporal simulation of tourist town growth is important for research on land use/cover change under the influence of urbanization. Many scholars have shown great interest in the unique pattern of driving urban development with tourism development. Based on the cellular automata (CA model, we simulated and predicted the spatiotemporal growth of Sanpo town in Hebei Province, using the tourism urbanization growth model. Results showed that (1 average annual growth rate of the entire region was 1.5 Ha2 per year from 2005 to 2010, 4 Ha2 per year from 2010 to 2015, and 2.5 Ha2 per year from 2015 to 2020; (2 urban growth rate increased yearly, with regional differences, and had a high degree of correlation with the Euclidean distance of town center, traffic route, attractions, and other factors; (3 Gougezhuang, an important village center in the west of the town, demonstrated traffic advantages and increased growth rate since 2010; (4 Magezhuang village has the largest population in the region, so economic advantages have driven the development of rural urbanization. It showed that CA had high reliability in simulating the spatiotemporal evolution of tourist town, which assists the study of spatiotemporal growth under urbanization and rational protection of tourism resources.

  14. Development of three-dimensional patient face model that enables real-time collision detection and cutting operation for a dental simulator.

    Science.gov (United States)

    Yamaguchi, Satoshi; Yamada, Yuya; Yoshida, Yoshinori; Noborio, Hiroshi; Imazato, Satoshi

    2012-01-01

    The virtual reality (VR) simulator is a useful tool to develop dental hand skill. However, VR simulations with reactions of patients have limited computational time to reproduce a face model. Our aim was to develop a patient face model that enables real-time collision detection and cutting operation by using stereolithography (STL) and deterministic finite automaton (DFA) data files. We evaluated dependence of computational cost and constructed the patient face model using the optimum condition for combining STL and DFA data files, and assessed the computational costs for operation in do-nothing, collision, cutting, and combination of collision and cutting. The face model was successfully constructed with low computational costs of 11.3, 18.3, 30.3, and 33.5 ms for do-nothing, collision, cutting, and collision and cutting, respectively. The patient face model could be useful for developing dental hand skill with VR.

  15. Selection of doublet cellular patterns in directional solidification through spatially periodic perturbations

    International Nuclear Information System (INIS)

    Losert, W.; Stillman, D.A.; Cummins, H.Z.; Kopczynski, P.; Rappel, W.; Karma, A.

    1998-01-01

    Pattern formation at the solid-liquid interface of a growing crystal was studied in directional solidification using a perturbation technique. We analyzed both experimentally and numerically the stability range and dynamical selection of cellular arrays of 'doublets' with asymmetric tip shapes, separated by alternate deep and shallow grooves. Applying an initial periodic perturbation of arbitrary wavelength to the unstable planar interface allowed us to force the interface to evolve into doublet states that would not otherwise be dynamically accessible from a planar interface. We determined systematically the ranges of wavelength corresponding to stable singlets, stable doublets, and transient unstable patterns. Experimentally, this was accomplished by applying a brief UV light pulse of a desired spatial periodicity to the planar interface during the planar-cellular transient using the model alloy Succinonitrile-Coumarin 152. Numerical simulations of the nonlinear evolution of the interface were performed starting from a small sinusoidal perturbation of the steady-state planar interface. These simulations were carried out using a computationally efficient phase-field symmetric model of directional solidification with recently reformulated asymptotics and vanishing kinetics [A. Karma and W.-J. Rappel, Phys. Rev. E 53 R3017 (1996); Phys. Rev. Lett. 77, 4050 (1996); Phys. Rev. E 57, 4323 (1998)], which allowed us to simulate spatially extended arrays that can be meaningfully compared to experiments. Simulations and experiments show remarkable qualitative agreement in the dynamic evolution, steady-state structure, and instability mechanisms of doublet cellular arrays. copyright 1998 The American Physical Society

  16. Analysis of phase dynamics in two-phase flow using latticegas automata

    International Nuclear Information System (INIS)

    Ohashi, H.; Hashimoto, Y.; Tsumaya, A.; Chen, Y.; Akiyama, M.

    1998-01-01

    In this paper, we describe lattice gas automaton models appropriate for two-phase flow simulation and their applications to study various phase dynamics of two-fluid mixtures. Several algorithms are added to the original immiscible Lattice Gas model to adjust surface tension and to introduce density difference between two fluids. Surface tension is controlled by the collision rules an difference in density is due to nonlocal forces between automaton particles. We simulate the relative motion of the dispersed phase in another continuous fluid. Deformation and disintegration of rising drops are reproduced. The interaction between multiple drops is also observed in calculations. Furutre, we obtain the transition of the two-phase flow pattern from bubbly, slug to annular flow. Density difference of two phase is one of the key ingredients to generate the annular flow pattern

  17. Irradiations of human melanoma cells by 14 MeV neutrons; survival curves interpretation; physical simulation of neutrons interactions in the cellular medium

    International Nuclear Information System (INIS)

    Bodez, Veronique

    2000-01-01

    14 MeV neutrons are used to irradiate human melanoma cells in order to study survival curves at low dose and low dose rate. We have simulated with the MCNP code, transport of neutrons through the experimental setup to evaluate the contamination of the primary beam by gamma and electrons, for the feasibility of our experiments. We have shown a rapid decrease of the survival curve in the first cGy followed by a plateau for doses up to 30 cGy; after we observed an exponential decrease. This results are observed for the first time, for neutrons at low dose rate (5 cGy/h). In parallel with this experimental point, we have developed a simulation code which permitted the study of neutrons interactions with the cellular medium for individual cells defined as in our experimental conditions. We show that most of the energy is deposited by protons from neutron interactions with external medium, and by heavy ions for interactions into the cell. On the other hand the code gives a good order of magnitude of the dose rate, compared to the experimental values given by silicon diodes. The first results show that we can, using a theory based on induced repair of cells, give an interpretation of the observed experimental plateau. We can give an estimation of the radial distribution of dose for the tracks of charged ions, we show the possibility of calculate interaction cross sections with cellular organelles. Such a work gives interesting perspectives for the future in radiobiology, radiotherapy or radioprotection. (author) [fr

  18. Design of Improved Arithmetic Logic Unit in Quantum-Dot Cellular Automata

    Science.gov (United States)

    Heikalabad, Saeed Rasouli; Gadim, Mahya Rahimpour

    2018-06-01

    The quantum-dot cellular automata (QCA) can be replaced to overcome the limitation of CMOS technology. An arithmetic logic unit (ALU) is a basic structure of any computer devices. In this paper, design of improved single-bit arithmetic logic unit in quantum dot cellular automata is presented. The proposed structure for ALU has AND, OR, XOR and ADD operations. A unique 2:1 multiplexer, an ultra-efficient two-input XOR and a low complexity full adder are used in the proposed structure. Also, an extended design of this structure is provided for two-bit ALU in this paper. The proposed structure of ALU is simulated by QCADesigner and simulation result is evaluated. Evaluation results show that the proposed design has best performance in terms of area, complexity and delay compared to the previous designs.

  19. Cellular-automation fluids: A model for flow in porous media

    International Nuclear Information System (INIS)

    Rothman, D.H.

    1987-01-01

    Because the intrinsic inhomogeneity of porous media makes the application of proper boundary conditions difficult, fluid flow through microgeometric models has typically been achieved with idealized arrays of geometrically simple pores, throats, and cracks. The author proposes here an attractive alternative, capable of freely and accurately modeling fluid flow in grossly irregular geometries. This new method numerically solves the Navier-Stokes equations using the cellular-automation fluid model introduced by Frisch, Hasslacher, and Pomeau. The cellular-automation fluid is extraordinarily simple - particles of unit mass traveling with unit velocity reside on a triangular lattice and obey elementary collisions rules - but capable of modeling much of the rich complexity of real fluid flow. The author shows how cellular-automation fluids are applied to the study of porous media. In particular, he discusses issues of scale on the cellular-automation lattice and present the results of 2-D simulations, including numerical estimation of permeability and verification of Darcy's law

  20. Investigation of cellular detonation structure formation via linear stability theory and 2D and 3D numerical simulations

    Science.gov (United States)

    Borisov, S. P.; Kudryavtsev, A. N.

    2017-10-01

    Linear and nonlinear stages of the instability of a plane detonation wave (DW) and the subsequent process of formation of cellular detonation structure are investigated. A simple model with one-step irreversible chemical reaction is used. The linear analysis is employed to predict the DW front structure at the early stages of its formation. An emerging eigenvalue problem is solved with a global method using a Chebyshev pseudospectral method and the LAPACK software library. A local iterative shooting procedure is used for eigenvalue refinement. Numerical simulations of a propagation of a DW in plane and rectangular channels are performed with a shock capturing WENO scheme of 5th order. A special method of a computational domain shift is implemented in order to maintain the DW in the domain. It is shown that the linear analysis gives certain predictions about the DW structure that are in agreement with the numerical simulations of early stages of DW propagation. However, at later stages, a merger of detonation cells occurs so that their number is approximately halved. Computations of DW propagation in a square channel reveal two different types of spatial structure of the DW front, "rectangular" and "diagonal" types. A spontaneous transition from the rectangular to diagonal type of structure is observed during propagation of the DW.

  1. Comparison of proposed countermeasures for dilemma zone at signalized intersections based on cellular automata simulations.

    Science.gov (United States)

    Wu, Yina; Abdel-Aty, Mohamed; Ding, Yaoxian; Jia, Bin; Shi, Qi; Yan, Xuedong

    2018-07-01

    The Type II dilemma zone describes the road segment to a signalized intersection where drivers have difficulties to decide either stop or go at the onset of yellow signal. Such phenomenon can result in an increased crash risk at signalized intersections. Different types of warning systems have been proposed to help drivers make decisions. Although the warning systems help to improve drivers' behavior, they also have several disadvantages such as increasing rear-end crashes or red-light running (RLR) violations. In this study, a new warning system called pavement marking with auxiliary countermeasure (PMAIC) is proposed to reduce the dilemma zone and enhance the traffic safety at signalized intersections. The proposed warning system integrates the pavement marking and flashing yellow system which can provide drivers with better suggestions about stop/go decisions based on their arriving time and speed. In order to evaluate the performance of the proposed warning system, this paper presents a cellular automata (CA) simulation study. The CA simulations are conducted for four different scenarios in total, including the typical intersection without warning system, the intersection with flashing green countermeasure, the intersection with pavement marking, and the intersection with the PMAIC warning system. Before the specific CA simulation analysis, a logistic regression model is calibrated based on field video data to predict drivers' general stop/go decisions. Also, the rules of vehicle movements in the CA models under the influence by different warning systems are proposed. The proxy indicators of rear-end crash and potential RLR violations were estimated and used to evaluate safety levels for the different scenarios. The simulation results showed that the PMAIC countermeasure consistently offered best performance to reduce rear-end crash and RLR violation. Meanwhile, the results indicate that the flashing-green countermeasure could not effectively reduce either rear

  2. The individual and interactive effects of tree-tree establishment competition and fire on savanna structure and dynamics

    OpenAIRE

    Calabrese, Justin; Vázquez, Federico; López, Cristóbal; San Miguel, Maxi; Grimm, Volker

    2010-01-01

    The mechanisms regulating savanna tree populations are still not well understood. Recent empirical work suggests that both tree-tree competition and fire are key factors in semi-arid to mesic savannas. However, the potential for competition to structure savannas, particularly in interaction with fire, has received little theoretical attention. We develop a minimalistic and analytically tractable stochastic cellular automaton to study the individual and combined effects of competition and fire...

  3. Predictive modeling of multicellular structure formation by using Cellular Particle Dynamics simulations

    Science.gov (United States)

    McCune, Matthew; Shafiee, Ashkan; Forgacs, Gabor; Kosztin, Ioan

    2014-03-01

    Cellular Particle Dynamics (CPD) is an effective computational method for describing and predicting the time evolution of biomechanical relaxation processes of multicellular systems. A typical example is the fusion of spheroidal bioink particles during post bioprinting structure formation. In CPD cells are modeled as an ensemble of cellular particles (CPs) that interact via short-range contact interactions, characterized by an attractive (adhesive interaction) and a repulsive (excluded volume interaction) component. The time evolution of the spatial conformation of the multicellular system is determined by following the trajectories of all CPs through integration of their equations of motion. CPD was successfully applied to describe and predict the fusion of 3D tissue construct involving identical spherical aggregates. Here, we demonstrate that CPD can also predict tissue formation involving uneven spherical aggregates whose volumes decrease during the fusion process. Work supported by NSF [PHY-0957914]. Computer time provided by the University of Missouri Bioinformatics Consortium.

  4. The effect of feedback on attitudes toward cellular phone use while driving: a comparison between novice and experienced drivers.

    Science.gov (United States)

    Wang, Ying; Zhang, Wei; Reimer, Bryan; Lavallière, Martin; Lesch, Mary F; Horrey, William J; Wu, Su

    2010-10-01

    To assess and compare the effectiveness of a simulation-based approach to change drivers' attitudes toward cellular phone use while driving for younger novice and older experienced drivers. Thirty young novice drivers were tested on a driving simulator in this study. Their performance in dealing with driving tasks was measured for a single task and dual tasks (driving while using a cellular phone) and compared to 30 older experienced drivers tested previously in another study. Half of the younger drivers received video-based feedback regarding their performance in the two conditions, with an emphasis on the contribution of dual-tasking to degraded performance. The other half did not receive any performance feedback. Drivers' perceptions and attitudes toward cellular phone use while driving were investigated by a questionnaire before, immediately after, and again one month following the simulation-based testing for both groups of drivers (feedback; no feedback). All drivers (including the novice and experienced) reported willingness to engage in driving and talking on a cellular phone in some situations. The simulated driving test showed that a secondary cellular phone task significantly degraded driving performance for both the novice and the experienced drivers. The feedback treatment group (both the novice and the experienced) showed significant attitude change toward cellular phone use while driving (toward being less favorable), whereas the control group had no attitude change. At the one-month follow-up, the benefit of feedback was sustained more so in the experienced driver group than the novice driver group, although both groups still benefited relative to the control conditions. Simulation-based feedback training is promising for short-term education in novice drivers but may be more effective in the long-term for drivers with higher levels of experience. Drivers with more experience appear to have a greater, more sustained benefit from the training than

  5. Urban Ecological Security Simulation and Prediction Using an Improved Cellular Automata (CA) Approach-A Case Study for the City of Wuhan in China.

    Science.gov (United States)

    Gao, Yuan; Zhang, Chuanrong; He, Qingsong; Liu, Yaolin

    2017-06-15

    Ecological security is an important research topic, especially urban ecological security. As highly populated eco-systems, cities always have more fragile ecological environments. However, most of the research on urban ecological security in literature has focused on evaluating current or past status of the ecological environment. Very little literature has carried out simulation or prediction of future ecological security. In addition, there is even less literature exploring the urban ecological environment at a fine scale. To fill-in the literature gap, in this study we simulated and predicted urban ecological security at a fine scale (district level) using an improved Cellular Automata (CA) approach. First we used the pressure-state-response (PSR) method based on grid-scale data to evaluate urban ecological security. Then, based on the evaluation results, we imported the geographically weighted regression (GWR) concept into the CA model to simulate and predict urban ecological security. We applied the improved CA approach in a case study-simulating and predicting urban ecological security for the city of Wuhan in Central China. By comparing the simulated ecological security values from 2010 using the improved CA model to the actual ecological security values of 2010, we got a relatively high value of the kappa coefficient, which indicates that this CA model can simulate or predict well future development of ecological security in Wuhan. Based on the prediction results for 2020, we made some policy recommendations for each district in Wuhan.

  6. Urban Ecological Security Simulation and Prediction Using an Improved Cellular Automata (CA) Approach—A Case Study for the City of Wuhan in China

    Science.gov (United States)

    Gao, Yuan; Zhang, Chuanrong; He, Qingsong; Liu, Yaolin

    2017-01-01

    Ecological security is an important research topic, especially urban ecological security. As highly populated eco-systems, cities always have more fragile ecological environments. However, most of the research on urban ecological security in literature has focused on evaluating current or past status of the ecological environment. Very little literature has carried out simulation or prediction of future ecological security. In addition, there is even less literature exploring the urban ecological environment at a fine scale. To fill-in the literature gap, in this study we simulated and predicted urban ecological security at a fine scale (district level) using an improved Cellular Automata (CA) approach. First we used the pressure-state-response (PSR) method based on grid-scale data to evaluate urban ecological security. Then, based on the evaluation results, we imported the geographically weighted regression (GWR) concept into the CA model to simulate and predict urban ecological security. We applied the improved CA approach in a case study—simulating and predicting urban ecological security for the city of Wuhan in Central China. By comparing the simulated ecological security values from 2010 using the improved CA model to the actual ecological security values of 2010, we got a relatively high value of the kappa coefficient, which indicates that this CA model can simulate or predict well future development of ecological security in Wuhan. Based on the prediction results for 2020, we made some policy recommendations for each district in Wuhan. PMID:28617348

  7. Mean Velocity Prediction Information Feedback Strategy in Two-Route Systems under ATIS

    Directory of Open Access Journals (Sweden)

    Jianqiang Wang

    2015-02-01

    Full Text Available Feedback contents of previous information feedback strategies in advanced traveler information systems are almost real-time traffic information. Compared with real-time information, prediction traffic information obtained by a reliable and effective prediction algorithm has many undisputable advantages. In prediction information environment, a traveler is prone to making a more rational route-choice. For these considerations, a mean velocity prediction information feedback strategy (MVPFS is presented. The approach adopts the autoregressive-integrated moving average model (ARIMA to forecast short-term traffic flow. Furthermore, prediction results of mean velocity are taken as feedback contents and displayed on a variable message sign to guide travelers' route-choice. Meanwhile, discrete choice model (Logit model is selected to imitate more appropriately travelers' route-choice behavior. In order to investigate the performance of MVPFS, a cellular automaton model with ARIMA is adopted to simulate a two-route scenario. The simulation shows that such innovative prediction feedback strategy is feasible and efficient. Even more importantly, this study demonstrates the excellence of prediction feedback ideology.

  8. Modeling of microstructure evolution of magnesium alloy during the high pressure die casting process

    International Nuclear Information System (INIS)

    Wu Mengwu; Xiong Shoumei

    2012-01-01

    Two important microstructure characteristics of high pressure die cast magnesium alloy are the externally solidified crystals (ESCs) and the fully divorced eutectic which form at the filling stage of the shot sleeve and at the last stage of solidification in the die cavity, respectively. Both of them have a significant influence on the mechanical properties and performance of magnesium alloy die castings. In the present paper, a numerical model based on the cellular automaton (CA) method was developed to simulate the microstructure evolution of magnesium alloy during cold-chamber high pressure die casting (HPDC) process. Modeling of dendritic growth of magnesium alloy with six-fold symmetry was achieved by defining a special neighbourhood configuration and calculating of the growth kinetics from complete solution of the transport equations. Special attention was paid to establish a nucleation model considering both of the nucleation of externally solidified crystals in the shot sleeve and the massive nucleation in the die cavity. Meanwhile, simulation of the formation of fully divorced eutectic was also taken into account in the present CA model. Validation was performed and the capability of the present model was addressed by comparing the simulated results with those obtained by experiments.

  9. Simulation of changes in heavy metal contamination in farmland soils of a typical manufacturing center through logistic-based cellular automata modeling.

    Science.gov (United States)

    Qiu, Menglong; Wang, Qi; Li, Fangbai; Chen, Junjian; Yang, Guoyi; Liu, Liming

    2016-01-01

    A customized logistic-based cellular automata (CA) model was developed to simulate changes in heavy metal contamination (HMC) in farmland soils of Dongguan, a manufacturing center in Southern China, and to discover the relationship between HMC and related explanatory variables (continuous and categorical). The model was calibrated through the simulation and validation of HMC in 2012. Thereafter, the model was implemented for the scenario simulation of development alternatives for HMC in 2022. The HMC in 2002 and 2012 was determined through soil tests and cokriging. Continuous variables were divided into two groups by odds ratios. Positive variables (odds ratios >1) included the Nemerow synthetic pollution index in 2002, linear drainage density, distance from the city center, distance from the railway, slope, and secondary industrial output per unit of land. Negative variables (odds ratios <1) included elevation, distance from the road, distance from the key polluting enterprises, distance from the town center, soil pH, and distance from bodies of water. Categorical variables, including soil type, parent material type, organic content grade, and land use type, also significantly influenced HMC according to Wald statistics. The relative operating characteristic and kappa coefficients were 0.91 and 0.64, respectively, which proved the validity and accuracy of the model. The scenario simulation shows that the government should not only implement stricter environmental regulation but also strengthen the remediation of the current polluted area to effectively mitigate HMC.

  10. ChainMail based neural dynamics modeling of soft tissue deformation for surgical simulation.

    Science.gov (United States)

    Zhang, Jinao; Zhong, Yongmin; Smith, Julian; Gu, Chengfan

    2017-07-20

    Realistic and real-time modeling and simulation of soft tissue deformation is a fundamental research issue in the field of surgical simulation. In this paper, a novel cellular neural network approach is presented for modeling and simulation of soft tissue deformation by combining neural dynamics of cellular neural network with ChainMail mechanism. The proposed method formulates the problem of elastic deformation into cellular neural network activities to avoid the complex computation of elasticity. The local position adjustments of ChainMail are incorporated into the cellular neural network as the local connectivity of cells, through which the dynamic behaviors of soft tissue deformation are transformed into the neural dynamics of cellular neural network. Experiments demonstrate that the proposed neural network approach is capable of modeling the soft tissues' nonlinear deformation and typical mechanical behaviors. The proposed method not only improves ChainMail's linear deformation with the nonlinear characteristics of neural dynamics but also enables the cellular neural network to follow the principle of continuum mechanics to simulate soft tissue deformation.

  11. Error performance analysis in downlink cellular networks with interference management

    KAUST Repository

    Afify, Laila H.

    2015-05-01

    Modeling aggregate network interference in cellular networks has recently gained immense attention both in academia and industry. While stochastic geometry based models have succeeded to account for the cellular network geometry, they mostly abstract many important wireless communication system aspects (e.g., modulation techniques, signal recovery techniques). Recently, a novel stochastic geometry model, based on the Equivalent-in-Distribution (EiD) approach, succeeded to capture the aforementioned communication system aspects and extend the analysis to averaged error performance, however, on the expense of increasing the modeling complexity. Inspired by the EiD approach, the analysis developed in [1] takes into consideration the key system parameters, while providing a simple tractable analysis. In this paper, we extend this framework to study the effect of different interference management techniques in downlink cellular network. The accuracy of the proposed analysis is verified via Monte Carlo simulations.

  12. Multi-cellular logistics of collective cell migration.

    Directory of Open Access Journals (Sweden)

    Masataka Yamao

    Full Text Available During development, the formation of biological networks (such as organs and neuronal networks is controlled by multicellular transportation phenomena based on cell migration. In multi-cellular systems, cellular locomotion is restricted by physical interactions with other cells in a crowded space, similar to passengers pushing others out of their way on a packed train. The motion of individual cells is intrinsically stochastic and may be viewed as a type of random walk. However, this walk takes place in a noisy environment because the cell interacts with its randomly moving neighbors. Despite this randomness and complexity, development is highly orchestrated and precisely regulated, following genetic (and even epigenetic blueprints. Although individual cell migration has long been studied, the manner in which stochasticity affects multi-cellular transportation within the precisely controlled process of development remains largely unknown. To explore the general principles underlying multicellular migration, we focus on the migration of neural crest cells, which migrate collectively and form streams. We introduce a mechanical model of multi-cellular migration. Simulations based on the model show that the migration mode depends on the relative strengths of the noise from migratory and non-migratory cells. Strong noise from migratory cells and weak noise from surrounding cells causes "collective migration," whereas strong noise from non-migratory cells causes "dispersive migration." Moreover, our theoretical analyses reveal that migratory cells attract each other over long distances, even without direct mechanical contacts. This effective interaction depends on the stochasticity of the migratory and non-migratory cells. On the basis of these findings, we propose that stochastic behavior at the single-cell level works effectively and precisely to achieve collective migration in multi-cellular systems.

  13. Influence of the Investor's Behavior on the Complexity of the Stock Market

    Science.gov (United States)

    Atman, A. P. F.; Gonçalves, Bruna Amin

    2012-04-01

    One of the pillars of the finance theory is the efficient-market hypothesis, which is used to analyze the stock market. However, in recent years, this hypothesis has been questioned by a number of studies showing evidence of unusual behaviors in the returns of financial assets ("anomalies") caused by behavioral aspects of the economic agents. Therefore, it is time to initiate a debate about the efficient-market hypothesis and the "behavioral finances." We here introduce a cellular automaton model to study the stock market complexity, considering different behaviors of the economical agents. From the analysis of the stationary standard of investment observed in the simulations and the Hurst exponents obtained for the term series of stock index, we draw conclusions concerning the complexity of the model compared to real markets. We also investigate which conditions of the investors are able to influence the efficient market hypothesis statements.

  14. Synchronization of DNA array replication kinetics

    Science.gov (United States)

    Manturov, Alexey O.; Grigoryev, Anton V.

    2016-04-01

    In the present work we discuss the features of the DNA replication kinetics at the case of multiplicity of simultaneously elongated DNA fragments. The interaction between replicated DNA fragments is carried out by free protons that appears at the every nucleotide attachment at the free end of elongated DNA fragment. So there is feedback between free protons concentration and DNA-polymerase activity that appears as elongation rate dependence. We develop the numerical model based on a cellular automaton, which can simulate the elongation stage (growth of DNA strands) for DNA elongation process with conditions pointed above and we study the possibility of the DNA polymerases movement synchronization. The results obtained numerically can be useful for DNA polymerase movement detection and visualization of the elongation process in the case of massive DNA replication, eg, under PCR condition or for DNA "sequencing by synthesis" sequencing devices evaluation.

  15. 3D CAFE modeling of grain structures: application to primary dendritic and secondary eutectic solidification

    International Nuclear Information System (INIS)

    Carozzani, T; Digonnet, H; Gandin, Ch-A

    2012-01-01

    A three-dimensional model is presented for the prediction of grain structures formed in casting. It is based on direct tracking of grain boundaries using a cellular automaton (CA) method. The model is fully coupled with a solution of the heat flow computed with a finite element (FE) method. Several unique capabilities are implemented including (i) the possibility to track the development of several types of grain structures, e.g. dendritic and eutectic grains, (ii) a coupling scheme that permits iterations between the FE method and the CA method, and (iii) tabulated enthalpy curves for the solid and liquid phases that offer the possibility to work with multicomponent alloys. The present CAFE model is also fully parallelized and runs on a cluster of computers. Demonstration is provided by direct comparison between simulated and recorded cooling curves for a directionally solidified aluminum–7 wt% silicon alloy

  16. Sensitivity testing practice on pre-processing parameters in hard and soft coupled modeling

    Directory of Open Access Journals (Sweden)

    Z. Ignaszak

    2010-01-01

    Full Text Available This paper pays attention to the problem of practical applicability of coupled modeling with the use of hard and soft models types and necessity of adapted to that models data base possession. The data base tests results for cylindrical 30 mm diameter casting made of AlSi7Mg alloy were presented. In simulation tests that were applied the Calcosoft system with CAFE (Cellular Automaton Finite Element module. This module which belongs to „multiphysics” models enables structure prediction of complete casting with division of columnar and equiaxed crystals zones of -phase. Sensitivity tests of coupled model on the particular values parameters changing were made. On these basis it was determined the relations of CET (columnar-to-equaiaxed transition zone position influence. The example of virtual structure validation based on real structure with CET zone location and grain size was shown.

  17. Compression behavior of cellular metals with inhomogeneous mass distribution

    International Nuclear Information System (INIS)

    Foroughi, B.

    2001-05-01

    Mechanical behavior of two types of closed cell metals (ALULIGHT and ALPORAS) is investigated experimentally and numerically. Compressive tests performed on prismatic specimens indicate that inhomogeneities in the mass density distribution are a key factor in the deformation behavior of cellular metals. The three dimensional cellular structure of the investigated specimens is recorded using x-ray medical computed tomography (CT). A special procedure called density mapping method has been used to transfer the recorded CT data into a continuum by averaging over a certain domain (averaging domain). This continuum model is implemented using finite elements to study the effect of variations in local mass densities. The finite element model is performed by a simple regular discretization of a specimen's volume with elements which have constant edge length. Mechanical properties derived from compression tests of ALPORAS samples are assigned to the corresponding mesoscopic density value of each element. The effect of averaging domain size is studied to obtain a suitable dimension which fulfils the homogenization requirements and allows the evaluation of inhomogenities in the specimens. The formation and propagation of deformation band(s) and stress-strain responses of tested cellular metals are modeled with respect to their mass distribution. It is shown that the inhomogeneous density distribution leads to plastic strain localization and causes a monotonically increase of the stress in the plateau regime although no hardening response was considered for homogeneous material in this regime. The simulated plastic strain localization and the calculated stress-strain responses are compared with the experimental results. The stiffness values of experiment and simulation agree very well for both cellular materials. The values of plateau strength as well, but it differs in some cases of ALULIGHT samples, where the hardening response can be predicted at least qualitatively

  18. Referent 3D tumor model at cellular level in radionuclide therapy

    International Nuclear Information System (INIS)

    Spaic, R.; Ilic, R.D.; Petrovic, B.J.

    2002-01-01

    Aim Conventional internal dosimetry has a lot of limitations because of tumor dose nonuniformity. The best approach for absorbed dose at cellular level for different tumors in radionuclide therapy calculation is Monte Carlo method. The purpose of this study is to introduce referent tumor 3D model at cellular level for Monte Carlo simulation study in radionuclide therapy. Material and Methods The moment when tumor is detectable and when same therapy can start is time period in which referent 3D tumor model at cellular level was defined. In accordance with tumor growth rate at that moment he was a sphere with same radius (10 000 μm). In that tumor there are cells or cluster of cells, which are randomly distributed spheres. Distribution of cells/cluster of cells can be calculated from histology data but it was assumed that this distribution is normal with the same mean value and standard deviation (100±50 mm). Second parameter, which was selected to define referent tumor, is volume density of cells (30%). In this referent tumor there are no necroses. Stroma is defined as space between spheres with same concentration of materials as in spheres. Results: Referent tumor defined on this way have about 2,2 10 5 cells or cluster of cells random distributed. Using this referent 3D tumor model and for same concentration of radionuclides (1:100) and energy of beta emitters (1000 keV) which are homogeneously distributed in labeled cells absorbed dose for all cells was calculated. Simulations are done using FOTELP Monte Carlo code, which is modified for this purposes. Results of absorbed dose in cells are given in numerical values (1D distribution) and as the images (2D or 3D distributions). Conclusion Geometrical module for Monte Carlo simulation study can be standardized by introducing referent 3D tumor model at cellular level. This referent 3D tumor model gives most realistic presentation of different tumors at the moment of their detectability. Referent 3D tumor model at

  19. Fluid Flow and Heat Transfer in Cellular Solids

    OpenAIRE

    Ettrich, Jörg

    2014-01-01

    To determine the characteristics and properties of cellular solids for an application, and to allow a systematic practical use by means of correlations and modelling approaches, we perform experimental investigations and develop numerical methods. In view of coupled multi-physics simulations, we employ the phase-field method. Finally, the applicability is demonstrated exemplarily for open-cell metal foams, providing qualitative and quantitative comparison with experimental data.

  20. Microscopic and macroscopic models for pedestrian crowds

    OpenAIRE

    Makmul, Juntima

    2016-01-01

    This thesis is concerned with microscopic and macroscopic models for pedes- trian crowds. In the first chapter, we consider pedestrians exit choices and model human behaviour in an evacuation process. Two microscopic models, discrete and continuous, are studied in this chapter. The former is a cellular automaton model and the latter is a social force model. Different numerical test cases are investigated and their results are compared. In chapter 2, a hierarchy of models for...

  1. Study of cellular retention of HMPAO and ECD in a model simulating the blood-brain barrier; Etude de la retention cellulaire de l`HMPAO et de l`ECD dans un modele simulant la barriere hematoencephalique

    Energy Technology Data Exchange (ETDEWEB)

    Ponce, C.; Pittet, N.; Slosman, D.O. [HUG, 1211 Geneve 14, (Switzerland)

    1997-12-31

    The HMPAO and ECD are two technetium-labelled lipophilic agents clinically used in the imagery of cerebral perfusion. These molecules cross the membranes and are retained inside the cell after being converted to a hydrophilic form. The aim of this study is to establish the distribution of this retention at the level of blood-brain barrier (BBB) and nerve cells. The incorporation of HMPAO or ECD was studied on a model of co-culture simulating the BBB by means of a T84 single-cell layer of tight junction separated from another layer of U373 astrocyte cells. The cell quality and tight junction permeability were evaluated by the cellular retention of 111-indium chloride and by para-cellular diffusion of {sup 14}C mannitol,d-1. The values reported below were obtained at 180 minutes when the radiotracers were added near the `T84 layer`. The cell quality is validated by the low cellular retention of the indium chloride(2.3{+-}0.3 {mu}g{sup -1} for the T84 cells and 8.2{+-}5.8 {mu}g{sup -1} for the U373 cells). The activity of {sup 14}C mannitol,d-1 diminishes by 23 {+-} 5 % in the added compartment. The retention of ECD by the U373 cells is significantly higher (20.7 {+-}4.5 g{sup -1}) than that of T84 cells (2.9 {+-} 0.2 {mu}g{sup -1}). For HMPAO a non-significant tendency could be observed (49 {+-} 34 {mu}g{sup -1} for the U373 cells and 38 {+-} 25 {mu}g{sup -1} for the T84 cells)> The results of cellular retention of indium by HMPAO or ECD when added near `U373 layer` are not significantly different.In conclusion, independently of the side exposed to the radiotracers, one observes an enhanced incorporation of the U373 cells. The ensemble of these results represent additional arguments in favour of a specific cellular incorporation of the radiotracers, independent of the BBB permittivity

  2. Dengue fever spreading based on probabilistic cellular automata with two lattices

    Science.gov (United States)

    Pereira, F. M. M.; Schimit, P. H. T.

    2018-06-01

    Modeling and simulation of mosquito-borne diseases have gained attention due to a growing incidence in tropical countries in the past few years. Here, we study the dengue spreading in a population modeled by cellular automata, where there are two lattices to model the human-mosquitointeraction: one lattice for human individuals, and one lattice for mosquitoes in order to enable different dynamics in populations. The disease considered is the dengue fever with one, two or three different serotypes coexisting in population. Although many regions exhibit the incidence of only one serotype, here we set a complete framework to also study the occurrence of two and three serotypes at the same time in a population. Furthermore, the flexibility of the model allows its use to other mosquito-borne diseases, like chikungunya, yellow fever and malaria. An approximation of the cellular automata is proposed in terms of ordinary differential equations; the spreading of mosquitoes is studied and the influence of some model parameters are analyzed with numerical simulations. Finally, a method to combat dengue spreading is simulated based on a reduction of mosquito birth and mosquito bites in population.

  3. Formalizing Knowledge in Multi-Scale Agent-Based Simulations.

    Science.gov (United States)

    Somogyi, Endre; Sluka, James P; Glazier, James A

    2016-10-01

    Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused.

  4. Real-Time ECG Simulation for Hybrid Mock Circulatory Loops.

    Science.gov (United States)

    Korn, Leonie; Rüschen, Daniel; Zander, Niklas; Leonhardt, Steffen; Walter, Marian

    2018-02-01

    Classically, mock circulatory loops only simulate mechanical properties of the circulation. To connect the hydraulic world with electrophysiology, we present a real-time electrical activity model of the heart and show how to integrate this model into a real-time mock loop simulation. The model incorporates a predefined conduction pathway and a simplified volume conductor to solve the bidomain equations and the forward problem of electrocardiography, resulting in a physiological simulation of the electrocardiogram (ECG) at arbitrary electrode positions. A complete physiological simulation of the heart's excitation would be too CPU intensive. Thus, in our model, complexity was reduced to allow real-time simulation of ECG-triggered medical systems in vitro; this decreases time and cost in the development process. Conversely, the presented model can still be adapted to various pathologies by locally changing the properties of the heart's conduction pathway. To simulate the ECG, the heart is divided into suitable areas, which are innervated by the hierarchically structured conduction system. To distinguish different cardiac regions, a segmentation of the heart was performed. In these regions, Prim's algorithm was applied to identify the directed minimal spanning trees for conduction orientation. Each node of the tree was assigned to a cardiac action potential generated by its hybrid automaton to represent the heart's conduction system by the spatial distribution of action potentials. To generate the ECG output, the bidomain equations were implemented and a simple model of the volume conductor of the body was used to solve the forward problem of electrocardiography. As a result, the model simulates potentials at arbitrary electrode positions in real-time. To verify the developed real-time ECG model, measurements were made within a hybrid mock circulatory loop, including a simple ECG-triggered ventricular assist device control. The model's potential value is to simulate

  5. Computational complexity of symbolic dynamics at the onset of chaos

    Science.gov (United States)

    Lakdawala, Porus

    1996-05-01

    In a variety of studies of dynamical systems, the edge of order and chaos has been singled out as a region of complexity. It was suggested by Wolfram, on the basis of qualitative behavior of cellular automata, that the computational basis for modeling this region is the universal Turing machine. In this paper, following a suggestion of Crutchfield, we try to show that the Turing machine model may often be too powerful as a computational model to describe the boundary of order and chaos. In particular we study the region of the first accumulation of period doubling in unimodal and bimodal maps of the interval, from the point of view of language theory. We show that in relation to the ``extended'' Chomsky hierarchy, the relevant computational model in the unimodal case is the nested stack automaton or the related indexed languages, while the bimodal case is modeled by the linear bounded automaton or the related context-sensitive languages.

  6. Using cellular automata for parallel simulation of laser dynamics with dynamic load balancing

    NARCIS (Netherlands)

    Guisado, J.L.; Fernández de Vega, F.; Jiménez Morales, F.; Iskra, K.A.; Sloot, P.M.A.

    2008-01-01

    We present an analysis of the feasibility of executing a parallel bioinspired model of laser dynamics, based on cellular automata (CA), on the usual target platform of this kind of applications: a heterogeneous non-dedicated cluster. As this model employs a synchronous CA, using the single program,

  7. Opinion evolution based on cellular automata rules in small world networks

    Science.gov (United States)

    Shi, Xiao-Ming; Shi, Lun; Zhang, Jie-Fang

    2010-03-01

    In this paper, we apply cellular automata rules, which can be given by a truth table, to human memory. We design each memory as a tracking survey mode that keeps the most recent three opinions. Each cellular automata rule, as a personal mechanism, gives the final ruling in one time period based on the data stored in one's memory. The key focus of the paper is to research the evolution of people's attitudes to the same question. Based on a great deal of empirical observations from computer simulations, all the rules can be classified into 20 groups. We highlight the fact that the phenomenon shown by some rules belonging to the same group will be altered within several steps by other rules in different groups. It is truly amazing that, compared with the last hundreds of presidential voting in America, the eras of important events in America's history coincide with the simulation results obtained by our model.

  8. Cellular Neural Networks for NP-Hard Optimization

    Directory of Open Access Journals (Sweden)

    Mária Ercsey-Ravasz

    2009-02-01

    Full Text Available A cellular neural/nonlinear network (CNN is used for NP-hard optimization. We prove that a CNN in which the parameters of all cells can be separately controlled is the analog correspondent of a two-dimensional Ising-type (Edwards-Anderson spin-glass system. Using the properties of CNN, we show that one single operation (template always yields a local minimum of the spin-glass energy function. This way, a very fast optimization method, similar to simulated annealing, can be built. Estimating the simulation time needed on CNN-based computers, and comparing it with the time needed on normal digital computers using the simulated annealing algorithm, the results are astonishing. CNN computers could be faster than digital computers already at 10×10 lattice sizes. The local control of the template parameters was already partially realized on some of the hardwares, we think this study could further motivate their development in this direction.

  9. Prediction Based Energy Balancing Forwarding in Cellular Networks

    Directory of Open Access Journals (Sweden)

    Yang Jian-Jun

    2017-01-01

    Full Text Available In the recent cellular network technologies, relay stations extend cell coverage and enhance signal strength for mobile users. However, busy traffic makes the relay stations in hot area run out of energy quickly. Energy is a very important factor in the forwarding of cellular network since mobile users(cell phones in hot cells often suffer from low throughput due to energy lack problems. In many situations, the energy lack problems take place because the energy loading is not balanced. In this paper, we present a prediction based forwarding algorithm to let a mobile node dynamically select the next relay station with highest potential energy capacity to resume communication. Key to this strategy is that a relay station only maintains three past status, and then it is able to predict the potential energy capacity. Then, the node selects the next hop with potential maximal energy. Moreover, a location based algorithm is developed to let the mobile node figure out the target region in order to avoid flooding. Simulations demonstrate that our approach significantly increase the aggregate throughput and decrease the delay in cellular network environment.

  10. Cellular reprogramming dynamics follow a simple 1D reaction coordinate

    Science.gov (United States)

    Teja Pusuluri, Sai; Lang, Alex H.; Mehta, Pankaj; Castillo, Horacio E.

    2018-01-01

    Cellular reprogramming, the conversion of one cell type to another, induces global changes in gene expression involving thousands of genes, and understanding how cells globally alter their gene expression profile during reprogramming is an ongoing problem. Here we reanalyze time-course data on cellular reprogramming from differentiated cell types to induced pluripotent stem cells (iPSCs) and show that gene expression dynamics during reprogramming follow a simple 1D reaction coordinate. This reaction coordinate is independent of both the time it takes to reach the iPSC state as well as the details of the experimental protocol used. Using Monte-Carlo simulations, we show that such a reaction coordinate emerges from epigenetic landscape models where cellular reprogramming is viewed as a ‘barrier-crossing’ process between cell fates. Overall, our analysis and model suggest that gene expression dynamics during reprogramming follow a canonical trajectory consistent with the idea of an ‘optimal path’ in gene expression space for reprogramming.

  11. Digital Cellular Solid Pressure Vessels: A Novel Approach for Human Habitation in Space

    Science.gov (United States)

    Cellucci, Daniel; Jenett, Benjamin; Cheung, Kenneth C.

    2017-01-01

    It is widely assumed that human exploration beyond Earth's orbit will require vehicles capable of providing long duration habitats that simulate an Earth-like environment - consistent artificial gravity, breathable atmosphere, and sufficient living space- while requiring the minimum possible launch mass. This paper examines how the qualities of digital cellular solids - high-performance, repairability, reconfigurability, tunable mechanical response - allow the accomplishment of long-duration habitat objectives at a fraction of the mass required for traditional structural technologies. To illustrate the impact digital cellular solids could make as a replacement to conventional habitat subsystems, we compare recent proposed deep space habitat structural systems with a digital cellular solids pressure vessel design that consists of a carbon fiber reinforced polymer (CFRP) digital cellular solid cylindrical framework that is lined with an ultra-high molecular weight polyethylene (UHMWPE) skin. We use the analytical treatment of a linear specific modulus scaling cellular solid to find the minimum mass pressure vessel for a structure and find that, for equivalent habitable volume and appropriate safety factors, the use of digital cellular solids provides clear methods for producing structures that are not only repairable and reconfigurable, but also higher performance than their conventionally manufactured counterparts.

  12. Numerical calculations of effective elastic properties of two cellular structures

    International Nuclear Information System (INIS)

    Tuncer, Enis

    2005-01-01

    Young's moduli of regular two-dimensional truss-like and eye-shaped structures are simulated using the finite element method. The structures are idealizations of soft polymeric materials used in ferro-electret applications. In the simulations, the length scales of the smallest representative units are varied, which changes the dimensions of the cell walls in the structures. A power-law expression with a quadratic as the exponent term is proposed for the effective Young's moduli of the systems as a function of the solid volume fraction. The data are divided into three regions with respect to the volume fraction: low, intermediate and high. The parameters of the proposed power-law expression in each region are later represented as a function of the structural parameters, the unit-cell dimensions. The expression presented can be used to predict a structure/property relationship in materials with similar cellular structures. The contribution of the cell-wall thickness to the elastic properties becomes significant at concentrations >0.15. The cell-wall thickness is the most significant factor in predicting the effective Young's modulus of regular cellular structures at high volume fractions of solid. At lower concentrations of solid, the eye-shaped structure yields a lower Young's modulus than a truss-like structure with similar anisotropy. Comparison of the numerical results with those of experimental data for poly(propylene) show good agreement regarding the influence of cell-wall thickness on elastic properties of thin cellular films

  13. Cellular gravity

    NARCIS (Netherlands)

    F.C. Gruau; J.T. Tromp (John)

    1999-01-01

    textabstractWe consider the problem of establishing gravity in cellular automata. In particular, when cellular automata states can be partitioned into empty, particle, and wall types, with the latter enclosing rectangular areas, we desire rules that will make the particles fall down and pile up on

  14. Time-based Reconstruction of Free-streaming Data in CBM

    Science.gov (United States)

    Akishina, Valentina; Kisel, Ivan; Vassiliev, Iouri; Zyzak, Maksym

    2018-02-01

    Traditional latency-limited trigger architectures typical for conventional experiments are inapplicable for the CBM experiment. Instead, CBM will ship and collect time-stamped data into a readout buffer in a form of a time-slice of a certain length and deliver it to a large computer farm, where online event reconstruction and selection will be performed. Grouping measurements into physical collisions must be performed in software and requires reconstruction not only in space, but also in time, the so-called 4-dimensional track reconstruction and event building. The tracks, reconstructed with 4D Cellular Automaton track finder, are combined into event-corresponding clusters according to the estimated time in the target position and the errors, obtained with the Kalman Filter method. The reconstructed events are given as inputs to the KF Particle Finder package for short-lived particle reconstruction. The results of time-based reconstruction of simulated collisions in CBM are presented and discussed in details.

  15. Large-q correlations from a Hubble-type pion source

    International Nuclear Information System (INIS)

    Barghouty, A.F.; Miller, J.; Frankel, K.A.

    1993-01-01

    In two-pion correlation measurements from relativistic nuclear collisions, the correlation function, C 2 (q), appears to exhibit an oscillatory structure at large (q ≥100 MeV/c) relative momentum. If real, this structure may have consequences for the determination of the space-time extent of the pion source. A qualitatively similar feature is seen in cellular automaton simulations of a Lorentz gas. It has been argued phenomenologically that the q-dependent oscillations can arise from an interplay between successive scattering probabilities and density variations of an exploding pion source. To further illustrate this interplay we consider a Hubble-type free expansion model for the source in which the density is time-folded from an initial Gaussian. This allows the source expansion to enter as a dynamical variable in the source density p[r(t); t] and thus C 2 , along with any signature of the interplay between scattering and source density

  16. Design strategy of pH-sensitive triblock copolymer micelles for efficient cellular uptake by computer simulations

    Science.gov (United States)

    Xia, Qiang-sheng; Ding, Hong-ming; Ma, Yu-qiang

    2018-03-01

    Efficient delivery of nanoparticles into specific cell interiors is of great importance in biomedicine. Recently, the pH-responsive micelle has emerged as one potential nanocarrier to realize such purpose since there exist obvious pH differences between normal tissues and tumors. Herein, by using dissipative particle dynamics simulation, we investigate the interaction of the pH-sensitive triblock copolymer micelles composed of ligand (L), hydrophobic block (C) and polyelectrolyte block (P) with cell membrane. It is found that the structure rearrangement of the micelle can facilitate its penetration into the lower leaflet of the bilayer. However, when the ligand-receptor specific interaction is weak, the micelles may just fuse with the upper leaflet of the bilayer. Moreover, the ionization degree of polyelectrolyte block and the length of hydrophobic block also play a vital role in the penetration efficiency. Further, when the sequence of the L, P, C beads in the copolymers is changed, the translocation pathways of the micelles may change from direct penetration to Janus engulfment. The present study reveals the relationship between the molecular structure of the copolymer and the uptake of the pH-sensitive micelles, which may give some significant insights into the experimental design of responsive micellar nanocarriers for highly efficient cellular delivery.

  17. Time scale of diffusion in molecular and cellular biology

    International Nuclear Information System (INIS)

    Holcman, D; Schuss, Z

    2014-01-01

    Diffusion is the driver of critical biological processes in cellular and molecular biology. The diverse temporal scales of cellular function are determined by vastly diverse spatial scales in most biophysical processes. The latter are due, among others, to small binding sites inside or on the cell membrane or to narrow passages between large cellular compartments. The great disparity in scales is at the root of the difficulty in quantifying cell function from molecular dynamics and from simulations. The coarse-grained time scale of cellular function is determined from molecular diffusion by the mean first passage time of molecular Brownian motion to a small targets or through narrow passages. The narrow escape theory (NET) concerns this issue. The NET is ubiquitous in molecular and cellular biology and is manifested, among others, in chemical reactions, in the calculation of the effective diffusion coefficient of receptors diffusing on a neuronal cell membrane strewn with obstacles, in the quantification of the early steps of viral trafficking, in the regulation of diffusion between the mother and daughter cells during cell division, and many other cases. Brownian trajectories can represent the motion of a molecule, a protein, an ion in solution, a receptor in a cell or on its membrane, and many other biochemical processes. The small target can represent a binding site or an ionic channel, a hidden active site embedded in a complex protein structure, a receptor for a neurotransmitter on the membrane of a neuron, and so on. The mean time to attach to a receptor or activator determines diffusion fluxes that are key regulators of cell function. This review describes physical models of various subcellular microdomains, in which the NET coarse-grains the molecular scale to a higher cellular-level, thus clarifying the role of cell geometry in determining subcellular function. (topical review)

  18. Time scale of diffusion in molecular and cellular biology

    Science.gov (United States)

    Holcman, D.; Schuss, Z.

    2014-05-01

    Diffusion is the driver of critical biological processes in cellular and molecular biology. The diverse temporal scales of cellular function are determined by vastly diverse spatial scales in most biophysical processes. The latter are due, among others, to small binding sites inside or on the cell membrane or to narrow passages between large cellular compartments. The great disparity in scales is at the root of the difficulty in quantifying cell function from molecular dynamics and from simulations. The coarse-grained time scale of cellular function is determined from molecular diffusion by the mean first passage time of molecular Brownian motion to a small targets or through narrow passages. The narrow escape theory (NET) concerns this issue. The NET is ubiquitous in molecular and cellular biology and is manifested, among others, in chemical reactions, in the calculation of the effective diffusion coefficient of receptors diffusing on a neuronal cell membrane strewn with obstacles, in the quantification of the early steps of viral trafficking, in the regulation of diffusion between the mother and daughter cells during cell division, and many other cases. Brownian trajectories can represent the motion of a molecule, a protein, an ion in solution, a receptor in a cell or on its membrane, and many other biochemical processes. The small target can represent a binding site or an ionic channel, a hidden active site embedded in a complex protein structure, a receptor for a neurotransmitter on the membrane of a neuron, and so on. The mean time to attach to a receptor or activator determines diffusion fluxes that are key regulators of cell function. This review describes physical models of various subcellular microdomains, in which the NET coarse-grains the molecular scale to a higher cellular-level, thus clarifying the role of cell geometry in determining subcellular function.

  19. Simulation of Regionally Ecological Land Based on a Cellular Automation Model: A Case Study of Beijing, China

    Directory of Open Access Journals (Sweden)

    Xiubin Li

    2012-08-01

    Full Text Available Ecological land is like the “liver” of a city and is very useful to public health. Ecological land change is a spatially dynamic non-linear process under the interaction between natural and anthropogenic factors at different scales. In this study, by setting up natural development scenario, object orientation scenario and ecosystem priority scenario, a Cellular Automation (CA model has been established to simulate the evolution pattern of ecological land in Beijing in the year 2020. Under the natural development scenario, most of ecological land will be replaced by construction land and crop land. But under the scenarios of object orientation and ecosystem priority, the ecological land area will increase, especially under the scenario of ecosystem priority. When considering the factors such as total area of ecological land, loss of key ecological land and spatial patterns of land use, the scenarios from priority to inferiority are ecosystem priority, object orientation and natural development, so future land management policies in Beijing should be focused on conversion of cropland to forest, wetland protection and prohibition of exploitation of natural protection zones, water source areas and forest parks to maintain the safety of the regional ecosystem.

  20. Simulation of regionally ecological land based on a cellular automation model: a case study of Beijing, China.

    Science.gov (United States)

    Xie, Hualin; Kung, Chih-Chun; Zhang, Yanting; Li, Xiubin

    2012-08-01

    Ecological land is like the "liver" of a city and is very useful to public health. Ecological land change is a spatially dynamic non-linear process under the interaction between natural and anthropogenic factors at different scales. In this study, by setting up natural development scenario, object orientation scenario and ecosystem priority scenario, a Cellular Automation (CA) model has been established to simulate the evolution pattern of ecological land in Beijing in the year 2020. Under the natural development scenario, most of ecological land will be replaced by construction land and crop land. But under the scenarios of object orientation and ecosystem priority, the ecological land area will increase, especially under the scenario of ecosystem priority. When considering the factors such as total area of ecological land, loss of key ecological land and spatial patterns of land use, the scenarios from priority to inferiority are ecosystem priority, object orientation and natural development, so future land management policies in Beijing should be focused on conversion of cropland to forest, wetland protection and prohibition of exploitation of natural protection zones, water source areas and forest parks to maintain the safety of the regional ecosystem.

  1. Simulating the conversion of rural settlements to town land based on multi-agent systems and cellular automata.

    Science.gov (United States)

    Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

    2013-01-01

    Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans.

  2. Cellular automata in cytoskeletal lattices

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S A; Watt, R C; Hameroff, S R

    1984-01-01

    Cellular automata (CA) activities could mediate biological regulation and information processing via nonlinear electrodynamic effects in cytoskeletal lattice arrays. Frohlich coherent oscillations and other nonlinear mechanisms may effect discrete 10/sup -10/ to 10/sup -11/ s interval events which result in dynamic patterns in biolattices such as cylindrical protein polymers: microtubules (MT). Structural geometry and electrostatic forces of MT subunit dipole oscillations suggest neighbor rules among the hexagonally packed protein subunits. Computer simulations using these suggested rules and MT structural geometry demonstrate CA activities including dynamical and stable self-organizing patterns, oscillators, and traveling gliders. CA activities in MT and other cytoskeletal lattices may have important biological regulatory functions. 23 references, 6 figures, 1 table.

  3. Cellular signaling identifiability analysis: a case study.

    Science.gov (United States)

    Roper, Ryan T; Pia Saccomani, Maria; Vicini, Paolo

    2010-05-21

    Two primary purposes for mathematical modeling in cell biology are (1) simulation for making predictions of experimental outcomes and (2) parameter estimation for drawing inferences from experimental data about unobserved aspects of biological systems. While the former purpose has become common in the biological sciences, the latter is less common, particularly when studying cellular and subcellular phenomena such as signaling-the focus of the current study. Data are difficult to obtain at this level. Therefore, even models of only modest complexity can contain parameters for which the available data are insufficient for estimation. In the present study, we use a set of published cellular signaling models to address issues related to global parameter identifiability. That is, we address the following question: assuming known time courses for some model variables, which parameters is it theoretically impossible to estimate, even with continuous, noise-free data? Following an introduction to this problem and its relevance, we perform a full identifiability analysis on a set of cellular signaling models using DAISY (Differential Algebra for the Identifiability of SYstems). We use our analysis to bring to light important issues related to parameter identifiability in ordinary differential equation (ODE) models. We contend that this is, as of yet, an under-appreciated issue in biological modeling and, more particularly, cell biology. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. Analysis of Blocking Rate and Bandwidth Usage of Mobile IPTV Services in Wireless Cellular Networks

    Directory of Open Access Journals (Sweden)

    Mingfu Li

    2014-01-01

    Full Text Available Mobile IPTV services over wireless cellular networks become more and more popular, owing to the significant growth in access bandwidth of wireless cellular networks such as 3G/4G and WiMAX. However, the spectrum resources of wireless cellular networks is rare. How to enhance the spectral efficiency of mobile networks becomes an important issue. Unicast, broadcast, and multicast are the most important transport schemes for offering mobile IPTV services over wireless cellular networks. Therefore, bandwidth usages and blocking rates of unicast, broadcast, and multicast IPTV services were analyzed and compared in this paper. Simulations were also conducted to validate the analytical results. Numerical results demonstrate that the presented analysis is correct, and multicast scheme achieves the best bandwidth usage and blocking rate performance, relative to the other two schemes.

  5. Analysis of blocking rate and bandwidth usage of mobile IPTV services in wireless cellular networks.

    Science.gov (United States)

    Li, Mingfu

    2014-01-01

    Mobile IPTV services over wireless cellular networks become more and more popular, owing to the significant growth in access bandwidth of wireless cellular networks such as 3G/4G and WiMAX. However, the spectrum resources of wireless cellular networks is rare. How to enhance the spectral efficiency of mobile networks becomes an important issue. Unicast, broadcast, and multicast are the most important transport schemes for offering mobile IPTV services over wireless cellular networks. Therefore, bandwidth usages and blocking rates of unicast, broadcast, and multicast IPTV services were analyzed and compared in this paper. Simulations were also conducted to validate the analytical results. Numerical results demonstrate that the presented analysis is correct, and multicast scheme achieves the best bandwidth usage and blocking rate performance, relative to the other two schemes.

  6. Capacity Enhancement of Uni‐directional In‐band Full‐Duplex Cellular Networks through Co‐channel Interference Cancellation

    Directory of Open Access Journals (Sweden)

    Hyungsik Ju

    2018-03-01

    Full Text Available As implementation of the in‐band full duplex (IFD transceiver becomes feasible, research interest is growing with respect to using IFD communication with cellular networks. However, the cellular network in which the IFD communication is applied inevitably suffers from an increase of the co‐channel interference (CCI due to IFD simultaneous transmission and reception. In this paper, we analyze the performance of a cellular network based on uni‐directional IFD (UD‐IFD communication, wherein an IFD base station simultaneously supports downlink and uplink transmissions of half‐duplex (HD users. In addition, a multi‐pair CCI cancellation (MP‐CCIC method combining CCIC and user pairing is proposed to improve the performance of the UD‐IFD network. Simulation results showed that, compared to a conventional HD cellular network without using CCIC, capacity gain was not obtained in the UD‐IFD cellular network. On the other hand, when applying the proposed MP‐CCIC, the capacity of the UD‐IFD cellular network greatly improved compared to that of an HD cellular network.

  7. Integration of Neural Networks and Cellular Automata for Urban Planning

    Institute of Scientific and Technical Information of China (English)

    Anthony Gar-on Yeh; LI Xia

    2004-01-01

    This paper presents a new type of cellular automata (CA) model for the simulation of alternative land development using neural networks for urban planning. CA models can be regarded as a planning tool because they can generate alternative urban growth. Alternative development patterns can be formed by using different sets of parameter values in CA simulation. A critical issue is how to define parameter values for realistic and idealized simulation. This paper demonstrates that neural networks can simplify CA models but generate more plausible results. The simulation is based on a simple three-layer network with an output neuron to generate conversion probability. No transition rules are required for the simulation. Parameter values are automatically obtained from the training of network by using satellite remote sensing data. Original training data can be assessed and modified according to planning objectives. Alternative urban patterns can be easily formulated by using the modified training data sets rather than changing the model.

  8. A new optimization method based on cellular automata for VVER-1000 nuclear reactor loading pattern

    International Nuclear Information System (INIS)

    Fadaei, Amir Hosein; Setayeshi, Saeed

    2009-01-01

    This paper presents a new and innovative optimization technique, which uses cellular automata for solving multi-objective optimization problems. Due to its ability in simulating the local information while taking neighboring effects into account, the cellular automata technique is a powerful tool for optimization. The fuel-loading pattern in nuclear reactor cores is a major optimization problem. Due to the immensity of the search space in fuel management optimization problems, finding the optimum solution requires a huge amount of calculations in the classical method. The cellular automata models, based on local information, can reduce the computations significantly. In this study, reducing the power peaking factor, while increasing the initial excess reactivity inside the reactor core of VVER-1000, which are two apparently contradictory objectives, are considered as the objective functions. The result is an optimum configuration, which is in agreement with the pattern proposed by the designer. In order to gain confidence in the reliability of this method, the aforementioned problem was also solved using neural network and simulated annealing, and the results and procedures were compared.

  9. Numerical Analysis of Moisture Flow and Concrete Cracking by means of Lattice Type Models

    NARCIS (Netherlands)

    Jankovic, D.; Küntz, M.; Van Mier, J.G.M.

    2001-01-01

    Modelling of fluid-flow and the resulting effects on shrinkage and microcracking by means of a combination of two lattice models are presented. For the moisture transport, a Lattice Gas Automaton (LGA) is adopted since it can effectively model moisture loss, whereas for cracking simulation a Lattice

  10. Simulation of a plane wavefront propagating in cardiac tissue using a cellular automata model

    International Nuclear Information System (INIS)

    Barbosa, Carlos R Hall

    2003-01-01

    We present a detailed description of a cellular automata model for the propagation of action potential in a planar cardiac tissue, which is very fast and easy to use. The model incorporates anisotropy in the electrical conductivity and a spatial variation of the refractory time. The transmembrane potential distribution is directly derived from the cell states, and the intracellular and extracellular potential distributions are calculated for the particular case of a plane wavefront. Once the potential distributions are known, the associated current densities are calculated by Ohm's law, and the magnetic field is determined at a plane parallel to the cardiac tissue by applying the law of Biot and Savart. The results obtained for propagation speed and for magnetic field amplitude with the cellular automata model are compared with values predicted by the bidomain formulation, for various angles between wavefront propagation and fibre direction, characterizing excellent agreement between the models

  11. The Development of Design Tools for Fault Tolerant Quantum Dot Cellular Automata Based Logic

    Science.gov (United States)

    Armstrong, Curtis D.; Humphreys, William M.

    2003-01-01

    We are developing software to explore the fault tolerance of quantum dot cellular automata gate architectures in the presence of manufacturing variations and device defects. The Topology Optimization Methodology using Applied Statistics (TOMAS) framework extends the capabilities of the A Quantum Interconnected Network Array Simulator (AQUINAS) by adding front-end and back-end software and creating an environment that integrates all of these components. The front-end tools establish all simulation parameters, configure the simulation system, automate the Monte Carlo generation of simulation files, and execute the simulation of these files. The back-end tools perform automated data parsing, statistical analysis and report generation.

  12. Distributed scheduling for autonomous vehicles by reinforcement learning; Kyoka gakushu ni yoru mujin hansosha no bunsangata scheduling

    Energy Technology Data Exchange (ETDEWEB)

    Unoki, T.; Suetake, N. [Oki Electric Industry Co. Ltd., Tokyo (Japan)

    1997-08-20

    In this paper, we propose an autonomous vehicle scheduling schema in large physical distribution terminals publicly used as the next generation wide area physical distribution bases. This schema uses Learning Automaton for vehicles scheduling based on Contract Net Protocol, in order to obtain useful emergent behaviors of agents in the system based on the local decision-making of each agent. The state of the automaton is updated at each instant on the basis of new information that includes the arrival estimation time of vehicles. Each agent estimates the arrival time of vehicles by using Bayesian learning process. Using traffic simulation, we evaluate the schema in various simulated environments. The result shows the advantage of the schema over when each agent provides the same criteria from the top down, and each agent voluntarily generates criteria via interactions with the environment, playing an individual role in tie system. 22 refs., 5 figs., 2 tabs.

  13. Cellular MR Imaging

    Directory of Open Access Journals (Sweden)

    Michel Modo

    2005-07-01

    Full Text Available Cellular MR imaging is a young field that aims to visualize targeted cells in living organisms. In order to provide a different signal intensity of the targeted cell, they are either labeled with MR contrast agents in vivo or prelabeled in vitro. Either (ultrasmall superparamagnetic iron oxide [(USPIO] particles or (polymeric paramagnetic chelates can be used for this purpose. For in vivo cellular labeling, Gd3+- and Mn2+- chelates have mainly been used for targeted hepatobiliary imaging, and (USPIO-based cellular imaging has been focused on imaging of macrophage activity. Several of these magneto-pharmaceuticals have been FDA-approved or are in late-phase clinical trials. As for prelabeling of cells in vitro, a challenge has been to induce a sufficient uptake of contrast agents into nonphagocytic cells, without affecting normal cellular function. It appears that this issue has now largely been resolved, leading to an active research on monitoring the cellular biodistribution in vivo following transplantation or transfusion of these cells, including cell migration and trafficking. New applications of cellular MR imaging will be directed, for instance, towards our understanding of hematopoietic (immune cell trafficking and of novel guided (stem cell-based therapies aimed to be translated to the clinic in the future.

  14. Fuel Loss and Jams due to Pausing Railroad Crossings

    OpenAIRE

    Tomoeda, Akiyasu; Nishinari, Katsuhiro; Harada, Yoshiaki

    2008-01-01

    In Japan, all cars must pause before crossing the railroad for avoiding the accidents. This rule was established by a law in 1960. In fact, however, railroad crossings come to the serious bottlenecks because of this pausing rule and this bottleneck causes heavy jams. In this study, by using cellular automaton model we have investigated the traffic flow at railroad crossings in two cases: with pausing and without pausing. Moreover, the lost time due to pausing at railroad crossings have been a...

  15. Energy Cost Minimization in Heterogeneous Cellular Networks with Hybrid Energy Supplies

    Directory of Open Access Journals (Sweden)

    Bang Wang

    2016-01-01

    Full Text Available The ever increasing data demand has led to the significant increase of energy consumption in cellular mobile networks. Recent advancements in heterogeneous cellular networks and green energy supplied base stations provide promising solutions for cellular communications industry. In this article, we first review the motivations and challenges as well as approaches to address the energy cost minimization problem for such green heterogeneous networks. Owing to the diversities of mobile traffic and renewable energy, the energy cost minimization problem involves both temporal and spatial optimization of resource allocation. We next present a new solution to illustrate how to combine the optimization of the temporal green energy allocation and spatial mobile traffic distribution. The whole optimization problem is decomposed into four subproblems, and correspondingly our proposed solution is divided into four parts: energy consumption estimation, green energy allocation, user association, and green energy reallocation. Simulation results demonstrate that our proposed algorithm can significantly reduce the total energy cost.

  16. Applying genetic algorithms for calibrating a hexagonal cellular automata model for the simulation of debris flows characterised by strong inertial effects

    Science.gov (United States)

    Iovine, G.; D'Ambrosio, D.; Di Gregorio, S.

    2005-03-01

    In modelling complex a-centric phenomena which evolve through local interactions within a discrete time-space, cellular automata (CA) represent a valid alternative to standard solution methods based on differential equations. Flow-type phenomena (such as lava flows, pyroclastic flows, earth flows, and debris flows) can be viewed as a-centric dynamical systems, and they can therefore be properly investigated in CA terms. SCIDDICA S 4a is the last release of a two-dimensional hexagonal CA model for simulating debris flows characterised by strong inertial effects. S 4a has been obtained by progressively enriching an initial simplified model, originally derived for simulating very simple cases of slow-moving flow-type landslides. Using an empirical strategy, in S 4a, the inertial character of the flowing mass is translated into CA terms by means of local rules. In particular, in the transition function of the model, the distribution of landslide debris among the cells is obtained through a double cycle of computation. In the first phase, the inertial character of the landslide debris is taken into account by considering indicators of momentum. In the second phase, any remaining debris in the central cell is distributed among the adjacent cells, according to the principle of maximum possible equilibrium. The complexities of the model and of the phenomena to be simulated suggested the need for an automated technique of evaluation for the determination of the best set of global parameters. Accordingly, the model is calibrated using a genetic algorithm and by considering the May 1998 Curti-Sarno (Southern Italy) debris flow. The boundaries of the area affected by the debris flow are simulated well with the model. Errors computed by comparing the simulations with the mapped areal extent of the actual landslide are smaller than those previously obtained without genetic algorithms. As the experiments have been realised in a sequential computing environment, they could be

  17. Programmable cellular arrays. Faults testing and correcting in cellular arrays

    International Nuclear Information System (INIS)

    Cercel, L.

    1978-03-01

    A review of some recent researches about programmable cellular arrays in computing and digital processing of information systems is presented, and includes both combinational and sequential arrays, with full arbitrary behaviour, or which can realize better implementations of specialized blocks as: arithmetic units, counters, comparators, control systems, memory blocks, etc. Also, the paper presents applications of cellular arrays in microprogramming, in implementing of a specialized computer for matrix operations, in modeling of universal computing systems. The last section deals with problems of fault testing and correcting in cellular arrays. (author)

  18. Random-Access Technique for Self-Organization of 5G Millimeter-Wave Cellular Communications

    Directory of Open Access Journals (Sweden)

    Jasper Meynard Arana

    2016-01-01

    Full Text Available The random-access (RA technique is a key procedure in cellular networks and self-organizing networks (SONs, but the overall processing time of this technique in millimeter-wave (mm-wave cellular systems with directional beams is very long because RA preambles (RAPs should be transmitted in all directions of Tx and Rx beams. In this paper, two different types of preambles (RAP-1 and RAP-2 are proposed to reduce the processing time in the RA stage. After analyzing the correlation property, false-alarm probability, and detection probability of the proposed RAPs, we perform simulations to show that the RAP-2 is suitable for RA in mm-wave cellular systems with directional beams because of the smaller processing time and high detection probability in multiuser environments.

  19. Study of spatially extended dynamical systems using probabilistic cellular automata

    International Nuclear Information System (INIS)

    Vanag, Vladimir K

    1999-01-01

    Spatially extended dynamical systems are ubiquitous and include such things as insect and animal populations; complex chemical, technological, and geochemical processes; humanity itself, and much more. It is clearly desirable to have a certain universal tool with which the highly complex behaviour of nonlinear dynamical systems can be analyzed and modelled. For this purpose, cellular automata seem to be good candidates. In the present review, emphasis is placed on the possibilities that various types of probabilistic cellular automata (PCA), such as DSMC (direct simulation Monte Carlo) and LGCA (lattice-gas cellular automata), offer. The methods are primarily designed for modelling spatially extended dynamical systems with inner fluctuations accounted for. For the Willamowskii-Roessler and Oregonator models, PCA applications to the following problems are illustrated: the effect of fluctuations on the dynamics of nonlinear systems; Turing structure formation; the effect of hydrodynamic modes on the behaviour of nonlinear chemical systems (stirring effects); bifurcation changes in the dynamical regimes of complex systems with restricted geometry or low spatial dimension; and the description of chemical systems in microemulsions. (reviews of topical problems)

  20. Controlled cellular energy conversion in brown adipose tissue thermogenesis

    Science.gov (United States)

    Horowitz, J. M.; Plant, R. E.

    1978-01-01

    Brown adipose tissue serves as a model system for nonshivering thermogenesis (NST) since a) it has as a primary physiological function the conversion of chemical energy to heat; and b) preliminary data from other tissues involved in NST (e.g., muscle) indicate that parallel mechanisms may be involved. Now that biochemical pathways have been proposed for brown fat thermogenesis, cellular models consistent with a thermodynamic representation can be formulated. Stated concisely, the thermogenic mechanism in a brown fat cell can be considered as an energy converter involving a sequence of cellular events controlled by signals over the autonomic nervous system. A thermodynamic description for NST is developed in terms of a nonisothermal system under steady-state conditions using network thermodynamics. Pathways simulated include mitochondrial ATP synthesis, a Na+/K+ membrane pump, and ionic diffusion through the adipocyte membrane.

  1. The adaptive cruise control vehicles in the cellular automata model

    International Nuclear Information System (INIS)

    Jiang Rui; Wu Qingsong

    2006-01-01

    This Letter presented a cellular automata model where the adaptive cruise control vehicles are modelled. In this model, the constant time headway policy is adopted. The fundamental diagram is presented. The simulation results are in good agreement with the analytical ones. The mixture of ACC vehicles with manually driven vehicles is investigated. It is shown that with the introduction of ACC vehicles, the jam can be suppressed

  2. 47 CFR 22.970 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone...

    Science.gov (United States)

    2010-10-01

    ...-cellular 800 MHz licensees from cellular radiotelephone or part 90-800 MHz cellular systems. 22.970 Section... MOBILE SERVICES Cellular Radiotelephone Service § 22.970 Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone or part 90-800 MHz cellular systems. (a) Definition...

  3. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  4. Stochastic cellular automata model of cell migration, proliferation and differentiation: validation with in vitro cultures of muscle satellite cells.

    Science.gov (United States)

    Garijo, N; Manzano, R; Osta, R; Perez, M A

    2012-12-07

    Cell migration and proliferation has been modelled in the literature as a process similar to diffusion. However, using diffusion models to simulate the proliferation and migration of cells tends to create a homogeneous distribution in the cell density that does not correlate to empirical observations. In fact, the mechanism of cell dispersal is not diffusion. Cells disperse by crawling or proliferation, or are transported in a moving fluid. The use of cellular automata, particle models or cell-based models can overcome this limitation. This paper presents a stochastic cellular automata model to simulate the proliferation, migration and differentiation of cells. These processes are considered as completely stochastic as well as discrete. The model developed was applied to predict the behaviour of in vitro cell cultures performed with adult muscle satellite cells. Moreover, non homogeneous distribution of cells has been observed inside the culture well and, using the above mentioned stochastic cellular automata model, we have been able to predict this heterogeneous cell distribution and compute accurate quantitative results. Differentiation was also incorporated into the computational simulation. The results predicted the myotube formation that typically occurs with adult muscle satellite cells. In conclusion, we have shown how a stochastic cellular automata model can be implemented and is capable of reproducing the in vitro behaviour of adult muscle satellite cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. A cellular automata model of bone formation.

    Science.gov (United States)

    Van Scoy, Gabrielle K; George, Estee L; Opoku Asantewaa, Flora; Kerns, Lucy; Saunders, Marnie M; Prieto-Langarica, Alicia

    2017-04-01

    Bone remodeling is an elegantly orchestrated process by which osteocytes, osteoblasts and osteoclasts function as a syncytium to maintain or modify bone. On the microscopic level, bone consists of cells that create, destroy and monitor the bone matrix. These cells interact in a coordinated manner to maintain a tightly regulated homeostasis. It is this regulation that is responsible for the observed increase in bone gain in the dominant arm of a tennis player and the observed increase in bone loss associated with spaceflight and osteoporosis. The manner in which these cells interact to bring about a change in bone quality and quantity has yet to be fully elucidated. But efforts to understand the multicellular complexity can ultimately lead to eradication of metabolic bone diseases such as osteoporosis and improved implant longevity. Experimentally validated mathematical models that simulate functional activity and offer eventual predictive capabilities offer tremendous potential in understanding multicellular bone remodeling. Here we undertake the initial challenge to develop a mathematical model of bone formation validated with in vitro data obtained from osteoblastic bone cells induced to mineralize and quantified at 26 days of culture. A cellular automata model was constructed to simulate the in vitro characterization. Permutation tests were performed to compare the distribution of the mineralization in the cultures and the distribution of the mineralization in the mathematical models. The results of the permutation test show the distribution of mineralization from the characterization and mathematical model come from the same probability distribution, therefore validating the cellular automata model. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. 47 CFR 22.909 - Cellular markets.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Cellular markets. 22.909 Section 22.909... Cellular Radiotelephone Service § 22.909 Cellular markets. Cellular markets are standard geographic areas used by the FCC for administrative convenience in the licensing of cellular systems. Cellular markets...

  7. A Data-Driven, Integrated Flare Model Based on Self-Organized Criticality

    Science.gov (United States)

    Dimitropoulou, M.; Isliker, H.; Vlahos, L.; Georgoulis, M.

    2013-09-01

    We interpret solar flares as events originating in solar active regions having reached the self-organized critical state, by alternatively using two versions of an "integrated flare model" - one static and one dynamic. In both versions the initial conditions are derived from observations aiming to investigate whether well-known scaling laws observed in the distribution functions of characteristic flare parameters are reproduced after the self-organized critical state has been reached. In the static model, we first apply a nonlinear force-free extrapolation that reconstructs the three-dimensional magnetic fields from two-dimensional vector magnetograms. We then locate magnetic discontinuities exceeding a threshold in the Laplacian of the magnetic field. These discontinuities are relaxed in local diffusion events, implemented in the form of cellular-automaton evolution rules. Subsequent loading and relaxation steps lead the system to self-organized criticality, after which the statistical properties of the simulated events are examined. In the dynamic version we deploy an enhanced driving mechanism, which utilizes the observed evolution of active regions, making use of sequential vector magnetograms. We first apply the static cellular automaton model to consecutive solar vector magnetograms until the self-organized critical state is reached. We then evolve the magnetic field inbetween these processed snapshots through spline interpolation, acting as a natural driver in the dynamic model. The identification of magnetically unstable sites as well as their relaxation follow the same rules as in the static model after each interpolation step. Subsequent interpolation/driving and relaxation steps cover all transitions until the end of the sequence. Physical requirements, such as the divergence-free condition for the magnetic field vector, are approximately satisfied in both versions of the model. We obtain robust power laws in the distribution functions of the modelled

  8. Six-Correction Logic (SCL Gates in Quantum-dot Cellular Automata (QCA

    Directory of Open Access Journals (Sweden)

    Md. Anisur Rahman

    2015-11-01

    Full Text Available Quantum Dot Cellular Automata (QCA is a promising nanotechnology in Quantum electronics for its ultra low power consumption, faster speed and small size features. It has significant advantages over the Complementary Metal–Oxide–Semiconductor (CMOS technology. This paper present, a novel QCA representation of Six-Correction Logic (SCL gate based on QCA logic gates: the Maj3, Maj AND gate and Maj OR. In order to design and verify the functionality of the proposed layout, QCADesigner a familiar QCA simulator has been employed. The simulation results confirm correctness of the claims and its usefulness in designing a digital circuits.

  9. Channel Access and Power Control for Mobile Crowdsourcing in Device-to-Device Underlaid Cellular Networks

    Directory of Open Access Journals (Sweden)

    Yue Ma

    2018-01-01

    Full Text Available With the access of a myriad of smart handheld devices in cellular networks, mobile crowdsourcing becomes increasingly popular, which can leverage omnipresent mobile devices to promote the complicated crowdsourcing tasks. Device-to-device (D2D communication is highly desired in mobile crowdsourcing when cellular communications are costly. The D2D cellular network is more preferable for mobile crowdsourcing than conventional cellular network. Therefore, this paper addresses the channel access and power control problem in the D2D underlaid cellular networks. We propose a novel semidistributed network-assisted power and a channel access control scheme for D2D user equipment (DUE pieces. It can control the interference from DUE pieces to the cellular user accurately and has low information feedback overhead. For the proposed scheme, the stochastic geometry tool is employed and analytic expressions are derived for the coverage probabilities of both the cellular link and D2D links. We analyze the impact of key system parameters on the proposed scheme. The Pareto optimal access threshold maximizing the total area spectral efficiency is obtained. Unlike the existing works, the performances of the cellular link and D2D links are both considered. Simulation results show that the proposed method can improve the total area spectral efficiency significantly compared to existing schemes.

  10. Simulating the Conversion of Rural Settlements to Town Land Based on Multi-Agent Systems and Cellular Automata

    Science.gov (United States)

    Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

    2013-01-01

    Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans. PMID:24244472

  11. Application of lattice-gas cellular automata to the Brownian motion of solids in suspension

    International Nuclear Information System (INIS)

    Ladd, A.J.C.; Colvin, M.E.; Frenkel, D.

    1988-01-01

    An adaptation of lattice-gas cellular automata to the simulation of solid-fluid suspensions is described. The method incorporates both dissipative hydrodynamic forces and thermal fluctuations. At low solid densities, theoretical results for the drag force on a single disk and the viscosity of a suspension of disks are reproduced. The zero--shear-rate viscosity has been obtained over a range of packing fractions and results indicate that simulations of three-dimensional suspensions are feasible

  12. Model Checking Temporal Logic Formulas Using Sticker Automata

    Science.gov (United States)

    Feng, Changwei; Wu, Huanmei

    2017-01-01

    As an important complex problem, the temporal logic model checking problem is still far from being fully resolved under the circumstance of DNA computing, especially Computation Tree Logic (CTL), Interval Temporal Logic (ITL), and Projection Temporal Logic (PTL), because there is still a lack of approaches for DNA model checking. To address this challenge, a model checking method is proposed for checking the basic formulas in the above three temporal logic types with DNA molecules. First, one-type single-stranded DNA molecules are employed to encode the Finite State Automaton (FSA) model of the given basic formula so that a sticker automaton is obtained. On the other hand, other single-stranded DNA molecules are employed to encode the given system model so that the input strings of the sticker automaton are obtained. Next, a series of biochemical reactions are conducted between the above two types of single-stranded DNA molecules. It can then be decided whether the system satisfies the formula or not. As a result, we have developed a DNA-based approach for checking all the basic formulas of CTL, ITL, and PTL. The simulated results demonstrate the effectiveness of the new method. PMID:29119114

  13. On the Capacity of a Cellular CDMA System Reverse Channel

    National Research Council Canada - National Science Library

    Klitorakis, Petros

    2002-01-01

    .... The performance of the system is examined under several values of the standard deviation of lognormal shadowing and the power control error for various numbers of users and values of the Nakagami-m variable by using simulations. Finally, a barrage noise jammer will be introduced and its effect seen in the performance of the cellular communication system for a specific value of E(sub b)/N(sub o).

  14. Data Structure Analysis to Represent Basic Models of Finite State Automation

    Directory of Open Access Journals (Sweden)

    V. V. Gurenko

    2015-01-01

    Full Text Available Complex system engineering based on the automaton models requires a reasoned data structure selection to implement them. The problem of automaton representation and data structure selection to be used in it has been understudied. Arbitrary data structure selection for automaton model software implementation leads to unnecessary computational burden and reduces the developed system efficiency. This article proposes an approach to the reasoned selection of data structures to represent finite algoristic automaton basic models and gives practical considerations based on it.Static and dynamic data structures are proposed for three main ways to assign Mealy and Moore automatons: a transition table, a matrix of coupling and a transition graph. A thirddimensional array, a rectangular matrix and a matrix of lists are the static structures. Dynamic structures are list-oriented structures: two-level and three-level Ayliff vectors and a multi-linked list. These structures allow us to store all required information about finite state automaton model components - characteristic set cardinalities and data of transition and output functions.A criterion system is proposed for data structure comparative evaluation in virtue of algorithmic features of automata theory problems. The criteria focused on capacitive and time computational complexity of operations performed in tasks such as equivalent automaton conversions, proving of automaton equivalence and isomorphism, and automaton minimization.A data structure comparative analysis based on the criterion system has done for both static and dynamic type. The analysis showed advantages of the third-dimensional array, matrix and two-level Ayliff vector. These are structures that assign automaton by transition table. For these structures an experiment was done to measure the execution time of automation operations included in criterion system.The analysis of experiment results showed that a dynamic structure - two

  15. Properties of Phase Transition of Traffic Flow on Urban Expressway Systems with Ramps and Accessory Roads

    International Nuclear Information System (INIS)

    Mei Chaoqun; Liu Yejin

    2011-01-01

    In this paper, we develop a cellular automaton model to describe the phase transition of traffic flow on urban expressway systems with on-off-ramps and accessory roads. The lane changing rules are given in detailed, the numerical results show that the main road and the accessory road both produce phase transitions. These phase transitions will often be influenced by the number of lanes, lane changing, the ramp flow, the input flow rate, and the geometry structure. (interdisciplinary physics and related areas of science and technology)

  16. Computer-aided study of key factors determining high mechanical properties of nanostructured surface layers in metal-ceramic composites

    Science.gov (United States)

    Konovalenko, Igor S.; Shilko, Evgeny V.; Ovcharenko, Vladimir E.; Psakhie, Sergey G.

    2017-12-01

    The paper presents the movable cellular automaton method. It is based on numerical models of surface layers of the metal-ceramic composite NiCr-TiC modified under electron beam irradiation in inert gas plasmas. The models take into account different geometric, concentration and mechanical parameters of ceramic and metallic components. The authors study the contributions of key structural factors in mechanical properties of surface layers and determine the ranges of their variations by providing the optimum balance of strength, strain hardening and fracture toughness.

  17. An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Sheng [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China); Qu, Xiaobo [Griffith School of Engineering, Griffith University, Gold Coast, 4222 Australia (Australia); Xu, Cheng [Department of Transportation Management Engineering, Zhejiang Police College, Hangzhou, 310053 China (China); College of Transportation, Jilin University, Changchun, 130022 China (China); Ma, Dongfang, E-mail: mdf2004@zju.edu.cn [Ocean College, Zhejiang University, Hangzhou, 310058 China (China); Wang, Dianhai [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China)

    2015-10-16

    This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated.

  18. An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

    International Nuclear Information System (INIS)

    Jin, Sheng; Qu, Xiaobo; Xu, Cheng; Ma, Dongfang; Wang, Dianhai

    2015-01-01

    This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated

  19. Biomechanics of cellular solids.

    Science.gov (United States)

    Gibson, Lorna J

    2005-03-01

    Materials with a cellular structure are widespread in nature and include wood, cork, plant parenchyma and trabecular bone. Natural cellular materials are often mechanically efficient: the honeycomb-like microstructure of wood, for instance, gives it an exceptionally high performance index for resisting bending and buckling. Here we review the mechanics of a wide range of natural cellular materials and examine their role in lightweight natural sandwich structures (e.g. iris leaves) and natural tubular structures (e.g. plant stems or animal quills). We also describe two examples of engineered biomaterials with a cellular structure, designed to replace or regenerate tissue in the body.

  20. High-performance full adder architecture in quantum-dot cellular automata

    Directory of Open Access Journals (Sweden)

    Hamid Rashidi

    2017-06-01

    Full Text Available Quantum-dot cellular automata (QCA is a new and promising computation paradigm, which can be a viable replacement for the complementary metal–oxide–semiconductor technology at nano-scale level. This technology provides a possible solution for improving the computation in various computational applications. Two QCA full adder architectures are presented and evaluated: a new and efficient 1-bit QCA full adder architecture and a 4-bit QCA ripple carry adder (RCA architecture. The proposed architectures are simulated using QCADesigner tool version 2.0.1. These architectures are implemented with the coplanar crossover approach. The simulation results show that the proposed 1-bit QCA full adder and 4-bit QCA RCA architectures utilise 33 and 175 QCA cells, respectively. Our simulation results show that the proposed architectures outperform most results so far in the literature.

  1. Plate-impact loading of cellular structures formed by selective laser melting

    International Nuclear Information System (INIS)

    Winter, R E; Cotton, M; Harris, E J; Maw, J R; Chapman, D J; Eakins, D E; McShane, G

    2014-01-01

    Porous materials are of great interest because of improved energy absorption over their solid counterparts. Their properties, however, have been difficult to optimize. Additive manufacturing has emerged as a potential technique to closely define the structure and properties of porous components, i.e. density, strut width and pore size; however, the behaviour of these materials at very high impact energies remains largely unexplored. We describe an initial study of the dynamic compression response of lattice materials fabricated through additive manufacturing. Lattices consisting of an array of intersecting stainless steel rods were fabricated into discs using selective laser melting. The resulting discs were impacted against solid stainless steel targets at velocities ranging from 300 to 700 m s −1 using a gas gun. Continuum CTH simulations were performed to identify key features in the measured wave profiles, while 3D simulations, in which the individual cells were modelled, revealed details of microscale deformation during collapse of the lattice structure. The validated computer models have been used to provide an understanding of the deformation processes in the cellular samples. The study supports the optimization of cellular structures for application as energy absorbers. (paper)

  2. Cellular Reflectarray Antenna

    Science.gov (United States)

    Romanofsky, Robert R.

    2010-01-01

    The cellular reflectarray antenna is intended to replace conventional parabolic reflectors that must be physically aligned with a particular satellite in geostationary orbit. These arrays are designed for specified geographical locations, defined by latitude and longitude, each called a "cell." A particular cell occupies nominally 1,500 square miles (3,885 sq. km), but this varies according to latitude and longitude. The cellular reflectarray antenna designed for a particular cell is simply positioned to align with magnetic North, and the antenna surface is level (parallel to the ground). A given cellular reflectarray antenna will not operate in any other cell.

  3. A novel approach in optimization problem for research reactors fuel plate using a synergy between cellular automata and quasi-simulated annealing methods

    International Nuclear Information System (INIS)

    Barati, Ramin

    2014-01-01

    Highlights: • An innovative optimization technique for multi-objective optimization is presented. • The technique utilizes combination of CA and quasi-simulated annealing. • Mass and deformation of fuel plate are considered as objective functions. • Computational burden is significantly reduced compared to classic tools. - Abstract: This paper presents a new and innovative optimization technique utilizing combination of cellular automata (CA) and quasi-simulated annealing (QSA) as solver concerning conceptual design optimization which is indeed a multi-objective optimization problem. Integrating CA and QSA into a unified optimizer tool has a great potential for solving multi-objective optimization problems. Simulating neighborhood effects while taking local information into account from CA and accepting transitions based on decreasing of objective function and Boltzmann distribution from QSA as transition rule make this tool effective in multi-objective optimization. Optimization of fuel plate safety design while taking into account major goals of conceptual design such as improving reliability and life-time – which are the most significant elements during shutdown – is a major multi-objective optimization problem. Due to hugeness of search space in fuel plate optimization problem, finding optimum solution in classical methods requires a huge amount of calculation and CPU time. The CA models, utilizing local information, require considerably less computation. In this study, minimizing both mass and deformation of fuel plate of a multipurpose research reactor (MPRR) are considered as objective functions. Results, speed, and qualification of proposed method are comparable with those of genetic algorithm and neural network methods applied to this problem before

  4. Cell Based GIS as Cellular Automata for Disaster Spreading Predictions and Required Data Systems

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-03-01

    Full Text Available A method for prediction and simulation based on the Cell Based Geographic Information System(GIS as Cellular Automata (CA is proposed together with required data systems, in particular metasearch engine usage in an unified way. It is confirmed that the proposed cell based GIS as CA has flexible usage of the attribute information that is attached to the cell in concert with location information and does work for disaster spreading simulation and prediction.

  5. Topology optimization of adaptive fluid-actuated cellular structures with arbitrary polygonal motor cells

    International Nuclear Information System (INIS)

    Lv, Jun; Tang, Liang; Li, Wenbo; Liu, Lei; Zhang, Hongwu

    2016-01-01

    This paper mainly focuses on the fast and efficient design method for plant bioinspired fluidic cellular materials and structures composed of polygonal motor cells. Here we developed a novel structural optimization method with arbitrary polygonal coarse-grid elements based on multiscale finite element frameworks. The fluidic cellular structures are meshed with irregular polygonal coarse-grid elements according to their natural size and the shape of the imbedded motor cells. The multiscale base functions of solid displacement and hydraulic pressure are then constructed to bring the small-scale information of the irregular motor cells to the large-scale simulations on the polygonal coarse-grid elements. On this basis, a new topology optimization method based on the resulting polygonal coarse-grid elements is proposed to determine the optimal distributions or number of motor cells in the smart cellular structures. Three types of optimization problems are solved according to the usages of the fluidic cellular structures. Firstly, the proposed optimization method is utilized to minimize the system compliance of the load-bearing fluidic cellular structures. Second, the method is further extended to design biomimetic compliant actuators of the fluidic cellular materials due to the fact that non-uniform volume expansions of fluid in the cells can induce elastic action. Third, the optimization problem focuses on the weight minimization of the cellular structure under the constraints for the compliance of the whole system. Several representative examples are investigated to validate the effectiveness of the proposed polygon-based topology optimization method of the smart materials. (paper)

  6. A Computational Model of Cellular Engraftment on Lung Scaffolds.

    Science.gov (United States)

    Pothen, Joshua J; Rajendran, Vignesh; Wagner, Darcy; Weiss, Daniel J; Smith, Bradford J; Ma, Baoshun; Bates, Jason H T

    2016-01-01

    The possibility that stem cells might be used to regenerate tissue is now being investigated for a variety of organs, but these investigations are still essentially exploratory and have few predictive tools available to guide experimentation. We propose, in this study, that the field of lung tissue regeneration might be better served by predictive tools that treat stem cells as agents that obey certain rules of behavior governed by both their phenotype and their environment. Sufficient knowledge of these rules of behavior would then, in principle, allow lung tissue development to be simulated computationally. Toward this end, we developed a simple agent-based computational model to simulate geographic patterns of cells seeded onto a lung scaffold. Comparison of the simulated patterns to those observed experimentally supports the hypothesis that mesenchymal stem cells proliferate preferentially toward the scaffold boundary, whereas alveolar epithelial cells do not. This demonstrates that a computational model of this type has the potential to assist in the discovery of rules of cellular behavior.

  7. Linearizable cellular automata

    International Nuclear Information System (INIS)

    Nobe, Atsushi; Yura, Fumitaka

    2007-01-01

    The initial value problem for a class of reversible elementary cellular automata with periodic boundaries is reduced to an initial-boundary value problem for a class of linear systems on a finite commutative ring Z 2 . Moreover, a family of such linearizable cellular automata is given

  8. Electromagnetic cellular interactions.

    Science.gov (United States)

    Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan

    2011-05-01

    Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Effect of solid distribution on elastic properties of open-cell cellular solids using numerical and experimental methods.

    Science.gov (United States)

    Zargarian, A; Esfahanian, M; Kadkhodapour, J; Ziaei-Rad, S

    2014-09-01

    Effect of solid distribution between edges and vertices of three-dimensional cellular solid with an open-cell structure was investigated both numerically and experimentally. Finite element analysis (FEA) with continuum elements and appropriate periodic boundary condition was employed to calculate the elastic properties of cellular solids using tetrakaidecahedral (Kelvin) unit cell. Relative densities between 0.01 and 0.1 and various values of solid fractions were considered. In order to validate the numerical model, three scaffolds with the relative density of 0.08, but different amounts of solid in vertices, were fabricated via 3-D printing technique. Good agreement was observed between numerical simulation and experimental results. Results of numerical simulation showed that, at low relative densities (solid fraction in vertices. By fitting a curve to the data obtained from the numerical simulation and considering the relative density and solid fraction in vertices, empirical relations were derived for Young׳s modulus and Poisson׳s ratio. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Research and applications: Artificial intelligence

    Science.gov (United States)

    Chaitin, L. J.; Duda, R. O.; Johanson, P. A.; Raphael, B.; Rosen, C. A.; Yates, R. A.

    1970-01-01

    The program is reported for developing techniques in artificial intelligence and their application to the control of mobile automatons for carrying out tasks autonomously. Visual scene analysis, short-term problem solving, and long-term problem solving are discussed along with the PDP-15 simulator, LISP-FORTRAN-MACRO interface, resolution strategies, and cost effectiveness.

  11. Modeling of time dependent localized flow shear stress and its impact on cellular growth within additive manufactured titanium implants.

    Science.gov (United States)

    Zhang, Ziyu; Yuan, Lang; Lee, Peter D; Jones, Eric; Jones, Julian R

    2014-11-01

    Bone augmentation implants are porous to allow cellular growth, bone formation and fixation. However, the design of the pores is currently based on simple empirical rules, such as minimum pore and interconnects sizes. We present a three-dimensional (3D) transient model of cellular growth based on the Navier-Stokes equations that simulates the body fluid flow and stimulation of bone precursor cellular growth, attachment, and proliferation as a function of local flow shear stress. The model's effectiveness is demonstrated for two additive manufactured (AM) titanium scaffold architectures. The results demonstrate that there is a complex interaction of flow rate and strut architecture, resulting in partially randomized structures having a preferential impact on stimulating cell migration in 3D porous structures for higher flow rates. This novel result demonstrates the potential new insights that can be gained via the modeling tool developed, and how the model can be used to perform what-if simulations to design AM structures to specific functional requirements. © 2014 Wiley Periodicals, Inc.

  12. A 3D Cellular Automaton for Cell Differentiation in a Solid Tumor with Plasticity

    Science.gov (United States)

    Margarit, David H.; Romanelli, Lilia; Fendrik, Alejandro J.

    A model with spherical symmetry is proposed. We analyze the appropriate parameters of cell differentiation for different kinds of cells (Cancer Stem Cells (CSC) and Differentiated Cells (DC)). The plasticity (capacity to return from a DC to its previous state of CSC) is taken into account. Following this hypothesis, the dissemination of CSCs to another organ is analyzed. The location of the cells in the tumor and the plasticity range for possible metastasis is discussed.

  13. Using synchronization to improve the forecasting of large relaxations in a cellular-automaton model

    DEFF Research Database (Denmark)

    González, Á.; Gómez, J.B.; Vázquez-Prada, M.

    2004-01-01

    phenomena. In the new strategy, copies (clones) of the original system (the master) are defined, and they are driven using rules that tend to synchronize them with the master dynamics. The observation of definite patterns in the state of the clones is the signal for connecting an alarm in the original...

  14. Coupled THM processes in EDZ of crystalline rocks using an elasto-plastic cellular automaton

    Science.gov (United States)

    Pan, Peng-Zhi; Feng, Xia-Ting; Huang, Xiao-Hua; Cui, Qiang; Zhou, Hui

    2009-05-01

    This paper aims at a numerical study of coupled thermal, hydrological and mechanical processes in the excavation disturbed zones (EDZ) around nuclear waste emplacement drifts in fractured crystalline rocks. The study was conducted for two model domains close to an emplacement tunnel; (1) a near-field domain and (2) a smaller wall-block domain. Goodman element and weak element were used to represent the fractures in the rock mass and the rock matrix was represented as elasto-visco-plastic material. Mohr-Coulomb criterion and a non-associated plastic flow rule were adopted to consider the viscoplastic deformation in the EDZ. A relation between volumetric strain and permeability was established. Using a self-developed EPCA2D code, the elastic, elasto-plastic and creep analyses to study the evolution of stress and deformations, as well as failure and permeability evolution in the EDZ were conducted. Results indicate a strong impact of fractures, plastic deformation and time effects on the behavior of EDZ especially the evolution of permeability around the drift.

  15. Cellular Automata on Graphs: Topological Properties of ER Graphs Evolved towards Low-Entropy Dynamics

    Directory of Open Access Journals (Sweden)

    Marc-Thorsten Hütt

    2012-06-01

    Full Text Available Cellular automata (CA are a remarkably  efficient tool for exploring general properties of complex systems and spatiotemporal patterns arising from local rules. Totalistic cellular automata,  where the update  rules depend  only on the density of neighboring states, are at the same time a versatile  tool for exploring  dynamical  processes on graphs. Here we briefly review our previous results on cellular automata on graphs, emphasizing some systematic relationships between network architecture and dynamics identified in this way. We then extend the investigation  towards graphs obtained in a simulated-evolution procedure, starting from Erdő s–Rényi (ER graphs and selecting for low entropies of the CA dynamics. Our key result is a strong association of low Shannon entropies with a broadening of the graph’s degree distribution.

  16. Energy dissipation dataset for reversible logic gates in quantum dot-cellular automata

    Directory of Open Access Journals (Sweden)

    Ali Newaz Bahar

    2017-02-01

    Full Text Available This paper presents an energy dissipation dataset of different reversible logic gates in quantum-dot cellular automata. The proposed circuits have been designed and verified using QCADesigner simulator. Besides, the energy dissipation has been calculated under three different tunneling energy level at temperature T=2 K. For estimating the energy dissipation of proposed gates; QCAPro tool has been employed.

  17. Energy dissipation dataset for reversible logic gates in quantum dot-cellular automata.

    Science.gov (United States)

    Bahar, Ali Newaz; Rahman, Mohammad Maksudur; Nahid, Nur Mohammad; Hassan, Md Kamrul

    2017-02-01

    This paper presents an energy dissipation dataset of different reversible logic gates in quantum-dot cellular automata. The proposed circuits have been designed and verified using QCADesigner simulator. Besides, the energy dissipation has been calculated under three different tunneling energy level at temperature T =2 K. For estimating the energy dissipation of proposed gates; QCAPro tool has been employed.

  18. Evaluating impact of market changes on increasing cell-load variation in dynamic cellular manufacturing systems using a hybrid Tabu search and simulated annealing algorithms

    Directory of Open Access Journals (Sweden)

    Aidin Delgoshaei

    2016-06-01

    Full Text Available In this paper, a new method is proposed for scheduling dynamic cellular manufacturing systems (D-CMS in the presence of uncertain product demands. The aim of this method is to control the process of trading off between in-house manufacturing and outsourcing while product demands are uncertain and can be varied from period to period. To solve the proposed problem, a hybrid Tabu Search and Simulated Annealing are developed to overcome hardness of the proposed model and then results are compared with a Branch and Bound and Simulated Annealing algorithms. A Taguchi method (L_27 orthogonal optimization is used to estimate parameters of the proposed method in order to solve experiments derived from literature. An in-depth analysis is conducted on the results in consideration of various factors. For evaluating the system imbalance in dynamic market demands, a new measuring index is developed. Our findings indicate that the uncertain condition of market demands affects the routing of product parts and may induce machine-load variations that yield to cell-load diversity. The results showed that the proposed hybrid method can provide solutions with better quality.

  19. The discrete Toda equation revisited: dual β-Grothendieck polynomials, ultradiscretization, and static solitons

    Science.gov (United States)

    Iwao, Shinsuke; Nagai, Hidetomo

    2018-04-01

    This paper presents a study of the discrete Toda equation that was introduced in 1977. In this paper, it is proved that the determinantal solution of the discrete Toda equation, obtained via the Lax formalism, is naturally related to the dual Grothendieck polynomials, a K-theoretic generalization of the Schur polynomials. A tropical permanent solution to the ultradiscrete Toda equation is also derived. The proposed method gives a tropical algebraic representation of the static solitons. Lastly, a new cellular automaton realization of the ultradiscrete Toda equation is proposed.

  20. Ammonia-based quantum computer

    International Nuclear Information System (INIS)

    Ferguson, Andrew J.; Cain, Paul A.; Williams, David A.; Briggs, G. Andrew D.

    2002-01-01

    We propose a scheme for quantum computation using two eigenstates of ammonia or similar molecules. Individual ammonia molecules are confined inside fullerenes and used as two-level qubit systems. Interaction between these ammonia qubits takes place via the electric dipole moments, and in particular we show how a controlled-NOT gate could be implemented. After computation the qubit is measured with a single-electron electrometer sensitive enough to differentiate between the dipole moments of different states. We also discuss a possible implementation based on a quantum cellular automaton