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.     

Realization of a GaAs/AlGaAs-based quantum cellular automata cell

We report on the experimental demonstration of a four-dot cell on a GaAs/AlGaAs substrate fabricated using electron beam lithographically defined gates. These surface metallic gates form a pair of double quantum dots, as well as a pair of quantum point contacts that act as non-invasive voltage probes. This device is used to realize a quantum cellular automata cell and, in further experiments, we employ it to investigate photon assisted tunneling. These results prove that the four-dot cell is a good building block candidate toward fulfilling the scalability DiVincezo criteria.     

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.     

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.     

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.     

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 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.     

An efficient,scalable, regular clocking scheme based on quantum dot cellular automata

Analog Integrated Circuits and Signal Processing - The present CMOS VLSI technology is facing some challenges like working in nano scale, device density, power dissipation, operating frequency,...     

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.     

Design of a loop-based random access memory based on the nanoscale quantum dot cellular automata

Photonic Network Communications - The use of modern quantum dot cellular automata (QCA) on the nanoscale gives better results than complementary metal–oxide–semiconductor (CMOS)...     

Analysis of missing and additional cell defects in sequential quantum-dot cellular automata

The defect characterization of sequential devices and circuits, implemented by molecular quantum-dot cellular automata (QCA), is analyzed in this paper. A RS-type flip–flop is first introduced; this flip–flop takes into account the timing issues associated with the adiabatic switching of this technology and its requirements. It is then shown that a D-type flip–flop can be constructed with an embedded QCA wire which extends over multiple clocking zones. The logic-level characterization of both flip–flop devices is provided. A single additional and missing cell defect model is assumed for molecular implementation. For sequential circuits, defect characterization is pursued. It is shown that defects affect the functionality of basic QCA devices, resulting mostly in unwanted inversion and majority voter acting as a wire at logic level. In this paper, it is shown that a device-level characterization of the defects and faults can be consistently extended to a circuit-level analysis.     

Novel RAM cell designs based on inherent capabilities of quantum-dot cellular automata

Quantum Cellular Automata (QCA) is a novel and attractive method which enables designing and implementing high-performance and low-power consumption digital circuits at nano-scale. Since memory is one of the most applicable basic units in digital circuits, having a fast and optimized QCA-based memory cell is remarkable. Although there are some QCA structures for a memory cell in the literature, however, QCA characteristics may be used in designing a more optimized memory cell than blindly modeling CMOS logics in QCA. In this paper, two improved structures have been proposed for a loop-based Random Access Memory (RAM) cell. In the proposed methods, the inherent capabilities of QCA, such as the programmability of majority gate and the clocking mechanism have been considered. The first proposed method enjoys smaller number of cells and the wasted area has been reduced compared to traditional loop-based RAM cell. For the second proposed method, the memory access time has been duplicated in presence of smaller number of cells. Irregular placement of QCA cells in a QCA layout makes its realization troublesome. So, we have proposed alternative versions of the proposed methods that exploit regularity of clock zones in design and have compared them to each other. QCA designer has been employed for simulation of the proposed designs and proving their validity.     

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。     

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.     

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.     

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.     

Design and evaluation of new majority gate-based RAM cell in quantum-dot cellular automata

Quantum-dot cellular automata is one of the candidate technologies used in Nano scale computer design and a promising replacement for conventional CMOS circuits in the near future. Since memory is one of the significant components of any digital system, designing a high speed and well-optimized QCA random access memory (RAM) is a remarkable subject. In this paper, a new robust five-input majority gate is first presented, which is appropriate for implementation of simple and efficient QCA circuits in single layer. By employing this structure, a novel RAM cell architecture with set and reset ability is proposed. This architecture has a simple and robust structure that helps achieving minimal area, as well as reduction in hardware requirements and clocking zone numbers. Functional correctness of the presented structures is proved by using QCADesigner tool. Simulation results confirm efficiency and usefulness of the proposed architectures vis-à-vis state-of-the-art.     

Adder design using 5-input majority gate in a novel “Multilayer Gate Design Paradigm” for Quantum Dot Cellular Automata Circuits

This paper proposes a novel design paradigm for circuits designed in quantum dot cellular automata (QCA) technology. Previously reported QCA circuits in the literature have generally been designed in a single layer which is the main logical block in which the inverter and majority gate are on the base layer, except for the parts where multilayer wire crossing was used. In this paper the concept of multilayer wire crossing has been extended to design logic gates in multilayers. Using a 5-input majority gate in a multilayer, a 1-bit and 2-bit adder have been designed in the proposed multilayer gate design paradigm. A comparison has been made with some adders reported previously in the literature and it has been shown that circuits designed in the proposed design paradigm are much more efficient in terms of area, the requirement of QCA cells in the design and the input-output delay of the circuit. Over all, the availability of one additional spatial dimension makes the design process much more flexible and there is scope for the customizability of logic gate designs to make the circuit compact.     

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.