Evolving cellular automata schemes for protein folding modeling using the Rosetta atomic representation

Genetic Programming and Evolvable Machines - Protein folding is the dynamic process by which a protein folds into its final native structure. This is different to the traditional problem of the...     

Spatio-temporal organization of a cellular automaton model for computer network

It was unveiled by Ren et al. [Comput. Phys. Comm. (2001)] that congestion transition emerges in cellular automaton models for computer network and this NaSch network model with Q=1 has similar behaviours as the NaSch traffic model with maximum velocity v_max=1. For these two NaSch models, the main difference lies in a node cell contained in the NaSch network model. In this paper, we will focus on our further investigation on spatio-temporal organization of the NaSch network model. More interesting phenomena of phase transition are discovered. Firstly, fundamental diagram illustrates that when Q>1 for the NaSch network model it is significantly different from its counterpart, i.e. the NaSch traffic model in a road traffic system. The addition of a node cell, which is allowed to have more than one packets, will lead to generating a new phase. Secondly, in order to characterize phase transition occurred in the NaSch network model, an order parameter is presented with the use of the time average density of nearest-neighbor pairs m. The computational results obtained show that criticality will disappear in a strict sense if noise exists. Finally, two other numerical features, i.e. spatial correlation functions G(r) and relaxation times τ, are analyzed so as to deeply describe behaviours near critical points.     

Offset control of traffic signal using cellular automaton traffic model

This paper deals with an offset control of traffic signals using a cellular automaton traffic model. A stochastic optimal control method for distributed traffic signals is modified to achieve coordinated traffic signal control with the proposed offset control method. In the proposed coordinated traffic signal control method, splits of each cycle and common cycle length are calculated using a modified stochastic optimal control method, and then the offset is calculated using an estimation method based on a modified CA traffic model at intervals. Also, simulations are carried out at multiple intersections using a micro traffic simulator. The effectiveness of the proposed coordinated control method is proved by comparing with other traffic signal control methods such as pre-timed signal control, two types of the traditional coordinated control and distributed control.     

A simplified combat model based on a cellular automaton

The work is devoted to constructing a cellular automaton based model of motion and combat activity of systems of hierarchically organized agents with allowance for terrain ruggedness, communication channels between the agents, and the necessity of choosing behavior adequate to the current situation.     

行人交通微观动态元胞自动机仿真模型研究

在分析行人交通特性后,以元胞自动机（CA）和规则描述为理论基础,提出基于CA的行人仿真模型,以此建立相对于其他交通对象的行人避让模型。该方法以模型与现实世界的高相似性有效克服了精确数学模型在仿真行人交通时的难题。结合行人CA模型和行人避让模型开发了混合交通流仿真试验原型系统。仿真结果表明,该方法有效地模拟了现实交通状况,在城市交通规划、交通需求管理和交通控制等领域有着广泛的应用前景。     

Analysis of a cellular automaton model for car traffic with a slow-to-stop rule

We propose a modification of the widely known Benjamin–Johnson–Hui (BJH) cellular automaton model for single-lane traffic simulation. In particular, our model includes a ‘slow-to-stop’ rule that exhibits more realistic microscopic driver behaviour than the BJH model. We present some statistics related to fuel economy and pollution generation and show that our model differs greatly in these measures. We give concise results based on extensive simulations using our system.     

一种自组织的二维元胞自动机网络模型及分析

提出了一种自组织的二维元胞自动机网络模型,并研究了网络中的临界特征和长相关特性。模型中,每个元胞包含一个路由器和随机数目的终端,并且能独立地根据探测到的网络拥塞状况调节其终端的数据包发送速率。仿真结果表明,在拥塞控制机制的作用下,网络能自组织地工作在临界状态,虽然节点间呈现出明显的异构特征,但节点数据包排队长度在时间和空间上仍都表现出较强的相关性。     

一种改进的NS元胞自动机模型

研究改进了基于元胞自动机的一维NS交通模型，细化了元胞长度和时间步长，对静止车辆的加速能力进行了约束，用简单的方法解决了该模型中车辆的速度演化规则与前车速度无关的缺点。同时，考虑了交通密度对随机慢化概率的影响。计算机仿真表明：改进模型不仅得到了一些与其他元胞自动机模型共有的性质，且得到的基本图更加接近实测数据。     

Halting the hallmarks: a cellular automaton model of early cancer growth inhibition

Cancer treatment is a fragmented and varied process, as “cancer” is really hundreds of different diseases. The “hallmarks of cancer” proposed by Hanahan and Weinberg (Cell 100(1):57–70, 2000) are a framework for viewing cancer within a common set of underlying principles—ten properties that are common to almost all cancers, allowing them to grow uncontrollably and ravage the body. We used a cellular automaton model of tumour growth paired with lattice Boltzmann methods modelling oxygen flow to simulate combination drugs targeted at knocking out pairs of hallmarks. We found that knocking out some pairs of cancer-enabling hallmarks did not prevent tumour formation, while other pairs significantly prevent tumour growth (\(p=0.0004\) using Wilcoxon signed-rank adjusted with the Bonferroni correction for multiple comparisons). This is not what would be expected from models of knocking out the hallmarks individually, as many pairs did not have an additive effect but had either no statistically significant effect or a multiplicative one. We propose that targeting certain pairs of cancer hallmarks, specifically cancers ability to induce blood vessel development paired with another cancer hallmark, could prove an effective cancer treatment option.     

Prediction of traveling front behavior in a lattice-gas cellular automaton model for tumor invasion

Cancer invasion is the process of cells detaching from a primary tumor and infiltrating the healthy tissue. Cancer invasion has been recognized as a complex system, since a tumor’s invasive behavior emerges from the combined effect of tumor cell proliferation, tumor cell migration and cell–microenvironment interactions. Cellular automata (CA) provide simple models of self-organizing complex systems in which collective behavior can emerge out of an ensemble of many interacting “simple” components. Here, we introduce a lattice-gas cellular automaton (LGCA) model of tumor cell proliferation, necrosis and tumor cell migration. The impact of the tumor environment on tumor cells has been investigated in a previous study. Our analysis aims at predicting the velocity of the traveling invasion front, which depends upon fluctuations that arise from the motion of the discrete cells at the front. We find an excellent agreement between the velocities measured in simulations of the LGCA and an analytical estimate derived in the cut-off mean-field approximation via the discrete Lattice Boltzmann equation and its linearization. In particular, we predict the front velocity to scale with the square root of the product of probabilities for mitosis and the migration coefficient. Finally, we calculate the width of the traveling front which is found to be proportional to the front velocity.     

CURIE: a cellular automaton for concept drift detection

Data Mining and Knowledge Discovery - Data stream mining extracts information from large quantities of data flowing fast and continuously (data streams). They are usually affected by changes in the...     

Designing self-timed devices using the finite automaton model

The authors suggest a procedure for designing a self-timed device defined by the finite automaton model. This procedure proves useful when designing these devices using the available synchronous behavior specifications. They illustrate the effectiveness of their procedure by applying it to the design of a stack memory and constant acknowledgement delay counter     

大型客车影响的双车道多速混合交通流CA模型研究

在对现有经典交通流元胞自动机模型进行总体分析的基础上,结合我国高速公路特点,通过重新标定元胞长度、运行车速、随机慢化机制,制定车道转换规则,构建了周期边界条件下考虑大型客车影响的双车道多速混合交通流元胞自动机模型,并通过计算机模拟分析了速度、密度、流量三参数之间关系,寻找出了大型客车占有率、大型客车随机慢化概率、变换车道车辆数等因素对交通流的影响规律,为合理的组织高速公路交通管理提供了理论依据。     

On the hierarchy of conservation laws in a cellular automaton

Conservation laws in cellular automata (CA) are studied as an abstraction of the conservation laws observed in nature. In addition to the usual real-valued conservation laws we also consider more general group-valued and semigroup-valued conservation laws. The (algebraic) conservation laws in a CA form a hierarchy, based on the range of the interactions they take into account. The conservation laws with smaller interaction ranges are the homomorphic images of those with larger interaction ranges, and for each specific range there is a most general law that incorporates all those with that range. For one-dimensional CA, such a most general conservation law has—even in the semigroup-valued case—an effectively constructible finite presentation, while for higher-dimensional CA such effective construction exists only in the group-valued case. It is even undecidable whether a given two-dimensional CA conserves a given semigroup-valued energy assignment. Although the local properties of this hierarchy are tractable in the one-dimensional case, its global properties turn out to be undecidable. In particular, we prove that it is undecidable whether this hierarchy is trivial or unbounded. We point out some interconnections between the structure of this hierarchy and the dynamical properties of the CA. In particular, we show that positively expansive CA do not have non-trivial real-valued conservation laws.     

On a three-parameter quantum battle of the sexes cellular automaton

The dynamics of a spatial quantum formulation of the iterated battle of the sexes game is studied in this work. The game is played in the cellular automata manner, i.e., with local and synchronous interaction. The effect of spatial structure is assessed when allowing the players to adopt quantum strategies that are no restricted to any particular subset of the possible strategies.     

An FPGA implemented cellular automaton crowd evacuation model inspired by the electrostatic-induced potential fields

This paper studies the on-chip realisation of a dynamic model proposed to simulate crowd behaviour, originated from electrostatic-induced potential fields. It is based on cellular automata (CA), thus taking advantage of their inherent ability to represent sufficiently phenomena of arbitrary complexity and, additionally, to be simulated precisely by digital computers. The model combines electrostatic-induced potential fields to incorporate flexibility in the movement of pedestrians. It primarily calculates distances in an obstacle filled space based on the Euclidean metric. Furthermore, it adopts a computationally fast and efficient method to overcome trouble-inducing obstacles by shifting the moving mechanism to a potential field method based on Manhattan-distance. The hardware implementation of the model is based on FPGA logic. Initialisation of the dedicated processor takes place in collaboration with a detecting and tracking algorithm supported by cameras. The instant response of the processor provides the location of pedestrians around exits. Hardware implementation exploits the prominent feature of parallelism that CA structures inherently possess in contrast to the serial computers, thus accelerating the response of the model. Furthermore, FPGA implementation of the model is advantageous in terms of low-cost, high-speed, compactness and portability features. Finally, the processor could be used as a part of an embedded, real-time, decision support system, aiming at the efficient guidance of crowd in cases of mass egress.     

Utilizing a cellular automaton model to explore the influence of coastal flood adaptation strategies on Helsinki's urbanization patterns

A cellular automaton model (SLEUTH-3r) is utilized to explore the impacts of coastal flood risk management strategies on the urbanization parameters of Helsinki's metropolitan area, at a 50-m spatial resolution by 2040. The current urbanization trend is characterized by the consolidation of existing built-up land and loss of interspersed green spaces, whereas the most intense growth is forecast inside the coastal flood risk areas. This baseline is compared to strategies that test various responses of the planning system to real estate market forces and the spatial distribution of flood risks. A set of scenarios translates property price effects of flood risk information into various attraction-repulsion areas in and adjacent to the floodplain, while a second set explores varying degrees of restricting new growth in the flood risk zones without reference to the housing market.The simulations indicate that growth under all scenarios is distributed in a more fragmented manner relative to the baseline, which can be interpreted favorably regarding house prices and increased access to ecosystem services, although the indirect effects should also be considered. Demand for coastal flood-safe properties does not appear to automatically translate to refocusing of development toward those areas, unless planning interventions encourage this redistribution. The character of the planning system with respect to market drivers and the spatial distribution of risks and amenities is thus important. A mixture of market-based measures and moderate zoning interventions may be preferable for flood risk management and provide the necessary precision for adaptation strategies.     

A cellular automaton for the propagation of circular fronts and its applications

Artificial intelligence techniques are widely used to solve complicated manufacturing and fabrication process problems in today's industrial world. Cellular automata (CAs) have been applied numerous times as an evolvable technique to the solution of some of the aforementioned complicated problems with great success due to their inherent parallelism, structural locality, regularity and modularity. One of the most difficult problems that CAs dealt with in several cases (i.e. integrated circuit fabrication, pattern recognition and classification, computer aided design, machine vision, etc.) is the identification and the reproduction of circular fronts and shapes. In this paper a CA is used to propagate circular fronts. This CA has an extended Moore neighborhood and a relatively simple local rule based on Boolean operators. Simulation results of an integrated circuit fabrication process, namely chemical vapor deposition based on the proposed CA are also presented. These results were found to be in very good qualitative agreement with the experimental results published in the literature. Moreover, because of the CA's binary states and its local rule simplicity, the VLSI implementation of the proposed CA is straightforward.     

A new hardware module for automated visual inspection based on a cellular automaton architecture

This paper presents the design and VLSI implementation of a new automated visual inspection system based on a cellular automaton architecture, suitable for circular object inspection. Cellular Automata (CA) transform the area of the object of interest into a number of evolution steps in the CA space. The proposed technique does not require the extraction of image features, such as boundary length and total area, which are computationally expensive in other methods. The die size dimensions of the chip, for a 16×16 pixel image, are 3.73 mm×3.09 mm=11.52 mm² and its maximum frequency of operation is 25 MHz. Experimental results using computer-generated images, as well as real images obtained and processed through a commercial vision system, showing the suitability of the proposed hardware module for detecting circular objects, are also presented. Targeted applications include inspection tasks (accept/reject operations) of circular objects, such as tablets in the pharmaceutical industry, and detection of uncoated areas, foreign objects and level of bake in the confectionery and food industry.