ASEP Model Research Articles

Color-position symmetry in interacting particle systems

We prove a color-position symmetry for a class of ASEP-like interacting particle systems with discrete time on the one-dimensional lattice. The full space-time inhomogeneity of our systems allows to apply the result to colored (or multi-species) ASEP and stochastic vertex models for a certain class of initial/boundary conditions, generalizing previous results of Amir–Angel–Valko and Borodin–Wheeler. We are also able to use the symmetry, together with previously known results for uncolored models, to find novel asymptotic behavior of the second-class particles in several situations.

Transverse temperature interfaces in the Katz-Lebowitz-Spohn driven lattice gas.

We explore the intriguing spatial patterns that emerge in a two-dimensional spatially inhomogeneous Katz-Lebowitz-Spohn (KLS) driven lattice gas with attractive nearest-neighbor interactions. The domain is split into two regions with hopping rates governed by different temperatures T>T_{c} and T_{c}, respectively, where T_{c} indicates the critical temperature for phase ordering, and with the temperature boundaries oriented perpendicular to the drive. In the hotter region, the system behaves like the (totally) asymmetric exclusion processes (TASEP), and experiences particle blockage in front of the interface to the critical region. To explain this particle density accumulation near the interface, we have measured the steady-state current in the KLS model at T>T_{c} and found it to decay as 1/T. In analogy with TASEP systems containing "slow" bonds, we argue that transport in the high-temperature subsystem is impeded by the lower current in the cooler region, which tends to set the global stationary particle current value. This blockage is induced by the extended particle clusters, growing logarithmically with system size, in the critical region. We observe the density profiles in both high- and low-temperature subsystems to be similar to the well-characterized coexistence and maximal-current phases in (T)ASEP models with open boundary conditions, which are respectively governed by hyperbolic and trigonometric tangent functions. Yet if the lower temperature is set to T_{c}, we detect marked fluctuation corrections to the mean-field density profiles, e.g., the corresponding critical KLS power-law density decay near the interfaces into the cooler region.

A simple probabilistic model of ideal gases

We describe a discrete 3D model of ideal gas based on the idea that, on the microscopic level, the particles move randomly (as in ASEP models), instead of obeying Newton’s laws as prescribed by Boltzmann.

Jamological approach to steel production and logistics

We applied Jamological approach to steel plate production process. Jamology is the method to treats the actual complex flow problem with macroscopic view, which key tool is on ASEP model and the fundamental diagram. For abstraction of the actual plant, we applied ABC categorizing to the practical data according to the bottle neck process. Moreover, we analyzed the reason of make span variation and derived the optimal sequencing pattern by using pair gap list. We indicated effectiveness of the proposed algorithm based on a transition matrix for practical data and derived the corresponding fundamental diagram which is much different from the traffic flow case.

The modified ASEP as a model of ideal gas

A modified version of the ASEP model is interpreted as a two-dimensional model of ideal gas. Its properties are studied by simulating its behavior in different situations, using an animation program designed for that purpose.

Bidirectional transport and pulsing states in a multi-lane ASEP model

In this paper, we introduce an ASEP-like transport model for bidirectional motion ofparticles on a multi-lane lattice. The model is motivated by in vivo experiments onorganelle motility along a microtubule (MT), consisting of thirteen protofilaments, whereparticles are propelled by molecular motors (dynein and kinesin). In the model, organelles(particles) can switch directions of motion due to ‘tug-of-war’ events between counteractingmotors. Collisions of particles on the same lane can be cleared by switching to adjacentprotofilaments (lane changes).We analyse transport properties of the model with no-flux boundary conditions at one endof a MT (‘plus end’ or tip). We show that the ability to make lane changes can affect thetransport efficiency and the particle-direction change rate obtained from experiments isclose to optimal for achieving efficient motor and organelle transport in a living cell. Inparticular, we find a nonlinear scaling of the mean tip size (the number of particlesaccumulated at the tip) with injection rate and an associated phase transitionleading to pulsing states characterized by periodic filling and emptying of thesystem.

Molecular dynamics simulation of ribosome jam

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.

Eigenvectors of open XXZ and ASEP models for a class of non-diagonal boundary conditions

We present a generalization of the coordinate Bethe ansatz that allows us to solve integrable openXXZ and ASEP models with non-diagonal boundary matrices, provided their parameters obey somerelations. These relations extend the ones already known in the literature in the context of thealgebraic or functional Bethe ansatz. The eigenvectors are represented as sums over cosets of theBCn Weyl group.

Shock dynamics of two-lane driven lattice gases

Driven lattice gases such as those of the ASEP model are useful tools for the modelling ofvarious stochastic transport processes carried out by self-driven particles, such as molecularmotors or vehicles in road traffic. Often these processes take place in one-dimensionalsystems offering several tracks to the particles, and in many cases the particles are able tochange track with a given rate. In this work we consider the case of strong coupling wherethe rate of hopping along the tracks and the exchange rates are of the same order, andshow how a phenomenological approach based on a domain wall theory can beused to describe the dynamics of the system. In particular, the domain walls onthe different tracks form pairs, whose dynamics dominate the behaviour of thesystem.

On directed compact percolation near a damp wall

A percolation probability for directed, compact percolation near a damp wall, which interpolates between the previously examined cases, is derived exactly. We find that the critical exponent β = 2 in common with the dry wall, rather than the value previously found in the wet wall and bulk cases. The solution is found via a mapping to a particular model of directed walks. We evaluate the exact generating function for this walk model which is also related to the ASEP model of traffic flow. We compare the underlying mathematical structure of the various cases previously considered and this one by reviewing the common framework of solution via the mapping to different directed walk models.

National e-readiness: an evaluation model

How does one measure if, and how, a country is becoming 'e-ready'? This paper examines definitions of e-readiness and evaluates existing e-readiness models and the related assessment tools. This research proposes a model to evaluate the e-readiness of a nation based on four categories: access, society, economy and policy. The ASEP model of e-readiness suggests a methodology that reaches a geometric visualisation of the state of e-readiness within, and across, countries. The ASEP model is built on 103 indicators collected from various e-readiness tools and models. Indicators are quantified to calculate an overall e-readiness index for a country. The paper concludes with recommendations for using the ASEP model in future research.

Effect of a columnar defect on the shape of slow-combustion fronts.

We report experimental results for the behavior of slow-combustion fronts in the presence of a columnar defect with enhanced or reduced driving, and compare them with those of mean-field theory. We also compare them with simulation results for an analogous problem of driven flow of particles with hard-core repulsion (ASEP) and a single defect bond with a different hopping probability. The difference in the shape of the front profiles for enhanced vs reduced driving in the defect clearly demonstrates the existence of a Kardar-Parisi-Zhang-type nonlinear term in the effective evolution equation for the slow-combustion fronts. We also find that slow-combustion fronts display a faceted form for large enough enhanced driving, and that there is a corresponding increase then in the average front speed. This increase in the average front speed disappears at a nonzero enhanced driving in agreement with the simulated behavior of the ASEP model.