可编程细胞自动机伪随机序列发生方法

可编程细胞自动机不仅具有细胞自动机组成单元的简单规则性、单元之间作用的局部性和信息处理的高度并行性等特性,而且具有动力学行为的复杂变化性.基于具有不可约特征多项式的规则90/150加性细胞自动机的同构特性,本文提出了可编程细胞自动机伪随机序列发生方法,其系统的结构参数随时间变化而变化,从而使得系统具有复杂的动力学行为.计算机模拟实验表明基于可编程细胞自动机的伪随机序列发生方法实现简单,产生的伪随机序列具有周期大、速度高和随机统计特性好等优点.     

Universal cellular automaton cell using quantum cellular automata

In recent years cellular automata (CAs) have been used widely to model and simulate physical systems and also to solve scientific problems. CAs have also been successfully used as a VLSI architecture and have proved to be very efficient at least in terms of silicon-area utilisation and clock-speed maximisation. Quantum cellular automata (QCA) is one of the promising emerging technologies for nanoscale circuit implementation. QCA technology provides very high scale integration, very high switching frequency and very low power circuit characteristics. In the work reported here, a universal cellular automaton cell has been designed using QCA circuitry. The implementation of CAs using QCA nanoelectronic circuits not only drives the already developed systems based on CAs to the nanoelectronics era but improves their performance significantly.     

Training cellular automata for image processing.

Experiments were carried out to investigate the possibility of training cellular automata (CA) to perform several image processing tasks. Even if only binary images are considered, the space of all possible rule sets is still very large, and so the training process is the main bottleneck of such an approach. In this paper, the sequential floating forward search method for feature selection was used to select good rule sets for a range of tasks, namely noise filtering (also applied to grayscale images using threshold decomposition), thinning, and convex hulls. Various objective functions for driving the search were considered. Several modifications to the standard CA formulation were made (the B-rule and two-cycle CAs), which were found, in some cases, to improve performance.     

Parallel pseudorandom number generation in GaAs cellular automata for high speed circuit testing

To facilitate test vector generation for high-speed circuits, we present the design and circuit simulation of parallel pseudorandom number generators in GaAs technology. These PRNGs are based on hybrid cellular automata (CA) in which mixtures of local rules are employed in one dimensional arrays, with minimal delay due to having only local wiring between neighboring cells. HSPICE simulations of these circuits demonstrate that they operate at a clock frequency above 1 GHz. Delay simulations indicate that GaAs PRNGs based upon linear feedback shift registers, in contrast with hybrid CAs, exhibit a degradation in clock frequency due to the effects of global interconnects, and that this degradation increases with the register length.This work was supported by Micronet, by the Canadian Microelectronics Corporation, and by the Natural Sciences and Engineering Research Council of Canada.     

Computational integral imaging-based 3D digital watermarking scheme using cellular automata transform and maximum length cellular automata

A novel 3D watermarking algorithm by combining use of computational integral imaging (CII) and cellular automata transform (CAT) is proposed in this paper. In this proposed scheme, first, the original image signal is decomposed into three resolution levels by using the level-3 2D CAT, and meanwhile, the middle-frequency domains are obtained. Then, an elemental images (EIs) array is generated by recording the information of rays of light coming from an object through a pinhole array in the CII system. The EIs array is encrypted by linear maximum-length cellular automata as the encrypted watermark embedded into the CAT middle-frequency domains. Finally, the watermarked image is obtained by using the level-3 2D inverse CAT. To verify the usefulness of the proposed algorithm, we carry out the computational experiments and present the experimental results for various attacks. Experimental results show that this proposed watermarking system provides excellent results in unobtrusiveness and robustness.     

细胞自动机在密码中的应用

近年来,细胞自动机在密码上的应用得到了广泛关注。本文首先对细胞自动机的研究方法进行了描述,然后对构造具有最大周期细胞自动机的基本理论进行总结、最后综述了几个具有代表性的基于细胞自动机的密码。     

Pathological liver segmentation using stochastic resonance and cellular automata

Liver segmentation continues to remain a major challenge, largely due to its intensity complexity with surrounding anatomical structures (stomach, kidney, and heart), high noise level and lack of contrast in pathological computed tomography data. In this paper, we present an approach to reconstructing the liver surface in low contrast computed tomography. The main contributions are: (1) a stochastic resonance based methodology in discrete cosine transform domain is developed to enhance the contrast of pathological liver images, (2) a new formulation is proposed to prevent the object boundary, resulted by cellular automata method, from leaking into the surrounding areas of similar intensity, and (3) a level-set method is suggested to generate intermediate segmentation contours from two segmented slices distantly located in a subject sequence. We have tested the algorithm on real datasets obtained from two sources, Hamad General Hospital and MICCAI Grand Challenge workshop. Both qualitative and quantitative evaluation performed on liver data show promising segmentation accuracy when compared with ground truth data reflecting the potential of the proposed method.     

An enhanced high-speed multi-digit BCD adder using quantum-dot cellular automata

The advent of development of high-performance, low-power digital circuits is achieved by a suitable emerging nanodevice called quantum-dot cellular automata(QCA). Even though many efficient arithmetic circuits were designed using QCA, there is still a challenge to implement high-speed circuits in an optimized manner. Among these circuits, one of the essential structures is a parallel multi-digit decimal adder unit with significant speed which is very attractive for future environments. To achieve high speed, a new correction logic formulation method is proposed for single and multi-digit BCD adder. The proposed enhanced single-digit BCD adder(ESDBA) is 26% faster than the carry flow adder(CFA)-based BCD adder. The multi-digit operations are also performed using the proposed ESDBA, which is cascaded innovatively. The enhanced multi-digit BCD adder(EMDBA) performs two 4-digit and two 8-digit BCD addition 50% faster than the CFA-based BCD adder with the nominal overhead of the area. The EMDBA performs two 4-digit BCD addition 24% faster with 23% decrease in the area, similarly for 8-digit operation the EMDBA achieves 36% increase in speed with 21% less area compared to the existing carry look ahead(CLA)-based BCD adder design. The proposed multi-digit adder produces significantly less delay of(N-1)+3.5 clock cycles compared to the N*One digit BCD adder delay required by the conventional BCD adder method. It is observed that as per our knowledge this is the first innovative proposal for multi-digit BCD addition using QCA.     

Single-bit digital comparator circuit design using quantum-dot cellular automata nanotechnology

The large amount of secondary effects in complementary metal–oxide–semiconductor technology limits its application in the ultra-nanoscale region. Circuit designers explore a new technology for the ultra-nanoscale region, which is the quantum-dot cellular automata (QCA). Low-energy dissipation, high speed, and area efficiency are the key features of the QCA technology. This research proposes a novel, low-complexity, QCA-based one-bit digital comparator circuit for the ultra-nanoscale region. The performance of the proposed comparator circuit is presented in detail in this paper and compared with that of existing designs. The proposed QCA structure for the comparator circuit only consists of 19 QCA cells with two clock phases. QCA Designer-E and QCA Pro tools are applied to estimate the total energy dissipation. The proposed comparator saves 24.00% QCA cells, 25.00% cell area, 37.50% layout cost, and 78.11% energy dissipation compared with the best reported similar design.     

An efficient method for impulse noise reduction from images using fuzzy cellular automata

Impulse noise reduction from corrupted images plays an important role in image processing. This problem will also affect on image segmentation, object detection, edge detection, compression, etc. Generally, median filters or nonlinear filters have been used for noise reduction but these methods will destroy the natural texture and important information in the image like the edges. In this paper, to eliminate impulse noises from noisy images, we used a hybrid method based on cellular automata (CA) and fuzzy logic called Fuzzy Cellular Automata (FCA) in two steps. In the first step, based on statistical information, noisy pixels are detected by CA; then using this information, the noisy pixel will change by FCA. Regularly, CA is used for systems with simple components where the behavior of each component will be defined and updated based on its neighbors. The proposed hybrid method is characterized as simple, robust and parallel which keeps the important details of the image effectively. The proposed approach has been performed on well-known gray scale test images and compared with other conventional and famous algorithms, is more effective.     

Clocked molecular quantum-dot cellular automata

Quantum-dot cellular automata (QCA) is an approach to computing that eliminates the need for current switches by representing binary information as the configuration of charge among quantum dots. For molecular QCA, redox sites of molecules serve as the quantum dots. The Coulomb interaction between neighboring molecules provides device-device coupling. By introducing clocked control of the QCA cell, power gain, reduced power dissipation, and computational pipelining can be achieved. We present an ab initio analysis of a simple molecular system, which acts as a clocked molecular QCA cell. The intrinsic bistability of the molecular charge configuration results in dipole or quadrupole fields that couple strongly to the state of neighboring molecules. We show how clocked control of the molecular QCA can be accomplished with a local electric field.     

Distributed faulty node detection and recovery scheme for wireless sensor networks using cellular learning automata

Wireless Networks - In a wireless sensor network (WSN), there is always the possibility of failure in sensor nodes. Quality of Service (QoS) of WSNs is highly degraded due to the faulty sensor...     

可逆元胞自动机加密技术研究

利用可逆元胞自动机无信息损失和高度并行处理的特点,提出了一种新的基于可逆二阶触发元胞自动机的分组加密算法.该算法没有取整个规则空间为密钥空间,而是通过引入规则表的λ参数,对原本庞大的规则空间进行了划分,证明了满足λ=0.5的一类规则适合用于加密.经分析表明,与一般不可逆触发元胞自动机加密技术相比,这种可逆触发元胞自动机加密技术不仅提高了加密速度,而且增加了密钥空间,具有良好的抵抗蛮力攻击和差分分析的能力.     

Generating multimedia content with cellular automata

Researchers have long used cellular automata (CA), and in general parallel generative devices such as Lindenmayer systems, to produce images, fractals, growth, patterns in two dimensions, and sound. They usually implement these models on special-purpose architectures that often depend on the type of presentation being generated. This paper discusses the developed prototype for generating content, called extended cellular automata with pluggable multimedia elements (ExcapeMe). This prototype acts as an open environment that lets users execute CA in three dimensions and manage simultaneous rendering of CA using different forms of presentation. In principle, we can attach any type of multimedia presentation as a plug-in. The environment already supports ID, 2D, 2.5D, and 3D presentations, and we can apply sound rendering to CA of any dimension. The environment also supports interactively denning, editing, and executing CA as well as defining the mapping between the CA configurations and their actual rendering.     

A new quantum-dot cellular automata full-adder

A novel expandable five-input majority gate for quantum-dot cellular automata and a new full-adder cell are presented. Quantum-dot cellular automata (QCA) is an emerging technology and a possible alternative for semiconductor transistor based technologies. A novel QCA majority-logic gate is proposed. This component is suitable for designing QCA circuits. The gate is simple in structure and powerful in terms of implementing digital functions. By applying these kinds of gates, the hardware requirement for a QCA design can be reduced and circuits can be simpler in level, gate counts and clock phases. In order to verify the functionality of the proposed device, some physical proofs are provided. The proper functionality of the FA is checked by means of computer simulations using QCADesigner tool. Both simulation results and physical relations confirm our claims and its usefulness in designing every digital circuit.     

一种基于量子细胞自动机的三维量子细胞神经网络

以量子细胞自动机为神经元,提出了一种三维的量子细胞神经网络结构;该量子细胞网络包含上下两层的量子细胞自动机阵列,并引入了A模板、B模板以及阈值的概念.以量子细胞自动机的极化率为像素值,通过选择不同的模板、阈值等参数.使得量子细胞神经网络实现了"与"、"或"、"非"操作以及边缘提取等图像处理功能,并利用MATLAB进行了仿真验证,数值仿真结果验证了其在图像处理上的有效性.与传统的细胞神经网络相比,量子细胞神经网络易于实现超大规模且具有超低功耗、超高集成度等优点.     

Analytical method for cell displacement defect quantum-dot cellular automata primitive

Quantum-dot cellular automata (QCA) is an emerging computational paradigm which can overcome scaling limitations of the existing complementary metal oxide semiconductor (CMOS) technology. The existence of defects cannot be ignored, considering the fabrication of QCA devices at the molecular level where it could alter the functionality. Therefore, defects in QCA devices need to be analyzed. So far, the simulation-based displacement defect analysis has been presented in the literature, which results in an increased demand in the corresponding mathematical model. In this paper, the displacement defect analysis of the QCA main primitive, majority voter (MV), is presented and carried out both in simulation and mathematics, where the kink energy based mathematical model is applied. The results demonstrate that this model is valid for the displacement defect in QCA MV.     

基于元胞自动机的多重零水印算法

利用混沌序列随机选择图像元胞自动机变换的低频系数产生初始构型,元胞自动机根据初始构型演化出零水印,然后用其加载有意义的二值水印,从而实现多重水印的零嵌入,从根本上保证了水印的不可见性.由于算法是基于元胞自动机域的,充分利用了元胞自动机复杂多变的特性,使水印有很好的安全性.实验结果表明提出的算法有较好的鲁棒性,也很好地解决了常见零水印方案所面临的问题.     

Algorithm for synthesis of efficient S-boxes based on cellular automata

A method for synthesis of efficient schemes of S-boxes based on cellular automata satisfying the main criteria of cryptographic quality has been proposed. The cellular automata rules making it possible to obtain S-boxes satisfying the criterion of maximum avalanche effect were found.     

Planar fractal-tree arrays derived from cellular automata

A two-dimensional cellular automata is used to derive two novel planar fractal-tree arrays. The maximum Euclidean size, element count and the radiation pattern functions of a fractal stage are expressed in terms of easily computable recurrence relations. Computed results show that these have a better sidelobe performance for a low thinning factor and element count than some other fractal and algorithmically optimised non-fractal arrays