A signal distribution grid for quantum-dot cellular automata

Coplanar wire crossing has been a major challenge for quantum-dot cellular automata systems since their development. Several possible solutions have been presented, but they have either relied on non-adjacent cell interactions or have required switching time that scales with the number of inputs or outputs. In this paper, the authors present a signal distribution grid that enables multiple parallel crossings, while doing so with only adjacent cell interactions, a constant time for signal distribution regardless of the number of inputs or outputs, and regularly shaped and contiguous clocking regions that will be relatively easier to fabricate. The utility of this device is demonstrated by the design of a one-bit full adder that meets all of the listed requirements.     

A symmetric quantum-dot cellular automata design for 5-input majority gate

By the inevitable scaling down of the feature size of the MOS transistors which are deeper in nanoranges, the CMOS technology has encountered many critical challenges and problems such as very high leakage currents, reduced gate control, high power density, increased circuit noise sensitivity and very high lithography costs. Quantum-dot cellular automata (QCA) owing to its high device density, extremely low power consumption and very high switching speed could be a feasible competitive alternative. In this paper, a novel 5-input majority gate, an important fundamental building block in QCA circuits, is designed in a symmetric form. In addition to the majority gate, a SR latch, a SR gate and an efficient one bit QCA full adder are implemented employing the new 5-input majority gate. In order to verify the functionality of the proposed designs, QCADesigner tool is used. The results demonstrate that the proposed SR latch and full adder perform equally well or in many cases better than previous circuits.     

New approaches for modeling and simulation of quantum-dot cellular automata

In order to further development of the microelectronic systems and to achieve the circuits with higher speed, higher density and lower power consumption, new technologies to replace the conventional CMOS technology must be introduced. Quantum-dot cellular automata (QCA) is an emerging nanotechnology that provides a new method for computation at the nanoscale regime. In this paper, two methods e.g. artificial neural network and a mathematical algorithm based on the QCA cell–cell response function named Tansig method are used for the modeling and simulation of QCA circuits at the cell level. The accuracy and performance of the proposed methods are analyzed through few circuits. The results of these two approaches are compared with each other and QCADesigner software. The results show the feasibility and acceptable accuracy of these types of simulations. Also, these methods enable the simulation of large QCA circuits at the cell level with acceptable precision in a short time with the ability to implement in other circuit simulators such as HSPICE and so on.     

Analysis of field-driven clocking for molecular quantum-dot cellular automata based circuits

Molecular quantum-dot cellular automaton (QCA) offers an alternative paradigm for computing at the nano-scale. QCA circuits require an external clock which can be generated using a network of submerged electrodes to synchronize information flow and provide the required power to drive the computation. In this paper, the effect of electrode separation and applied potential on the likelihood of different QCA cell states of molecular cells located above and in between two adjacent electrodes is analyzed. Using this analysis, estimates of operational ranges are developed for the placement, applied potential, and relative phase between adjacent clocking electrodes to ensure that only those states that are used in the computation are energetically favorable. Conclusions on the trade-off between cell size, cell-to-cell distance, and applied clocking potential are drawn and the temperature dependence of the operation of fundamental QCA building blocks is considered.     

Power dissipation in clocking wires for clocked molecular quantum-dot cellular automata

In the molecular quantum-dot cellular automata (QCA) paradigm clocking wires are used to produce an electric field which is perpendicular to the device plane of surface-bound molecules and is sinusoidally modulated in space and time. This clocking field guides the data flow through the molecular QCA array. Power is dissipated in clocking wires due to the non-zero resistance of the conductors. We analyze quantitatively the amount of power dissipated in the clocking wires and find that in the relevant parameter range it is fairly small. Dissipation in the molecular devices themselves will likely dominate the energy budget.     

Deep learning with photonic neural cellular automata

Rapid advancements in deep learning over the past decade have fueled an insatiable demand for efficient and scalable hardware.Photonics offers a promising solution by leveraging the unique properties of light.However,conventional neural network architectures,which typically require dense programmable connections,pose several practical challenges for photonic realizations.To overcome these limitations,we propose and experimentally demonstrate Photonic Neural Cellular Automata(PNCA)for photonic deep learning with sparse connectivity.PNCA harnesses the speed and interconnectivity of photonics,as well as the self-organizing nature of cellular automata through local interactions to achieve robust,reliable,and efficient processing.We utilize linear light interference and parametric nonlinear optics for all-optical computations in a time-multiplexed photonic network to experimentally perform self-organized image classification.We demonstrate binary(two-class)classification of images using as few as 3 programmable photonic parameters,achieving high experimental accuracy with the ability to also recognize out-of-distribution data.The proposed PNCA approach can be adapted to a wide range of existing photonic hardware and provides a compelling alternative to conventional photonic neural networks by maximizing the advantages of light-based computing whilst mitigating their practical challenges.Our results showcase the potential of PNCA in advancing photonic deep learning and highlights a path for next-generation photonic computers.     

一种基于多目标遗传算法的CA加权测试生成方法

本文介绍一种内建自测试总体优化的测试生成方法,首先对细胞自动机的特点进行了介绍,还分析了细胞自动机结构的邻居关系和加权测试序列相关性,最后本文用多目标遗传算法来设计这种测试生成方法,并应用ISCAS＇85基准电路来验证此方法。通过对具体例子的各项指标比较,说明了这种内建自测试总体优化的测试生成方法比传统的测试方法具有优越性。     

基于蚁群元胞自动机理论的城市饱和负荷预测

随着中国经济的不断发展,城市饱和负荷的研究对未来电网发展的规划具有重大意义。介绍蚁群算法与元胞自动机的基本原理,通过组合两者的优点,建立蚁群元胞自动机的饱和负荷预测模型。该模型从土地性质转移角度出发,基于元胞自动机理论,提出土地性质元胞的转换规则,结合蚁群优化算法,得出土地性质转移率。并且通过S曲线法分析不同土地性质下饱和密度的状况。通过对某城市现状进行案例分析,论证了该方法的科学性。     

Calculating the steady-state polarizations of quantum cellular automata (QCA) circuits

We present on the use of well-known stochastic methods for computing the steady-state polarizations of quantum cellular automata (QCA) circuits. Typically, a Boltzmann distribution, which requires the exploration of the complete configuration space of an \(N\) -cell QCA circuit, is used to compute the \(2^N\) steady-states of the QCA circuit. However, the exponential growth in states as the circuit size grows makes computing the Boltzmann distribution infeasible for large circuits. Thus, we approximate the Boltzmann distribution of a QCA circuit by conducting a partial exploration of the complete configuration space by means of a Monte Carlo method, simulated annealing, and a genetic algorithm. The approximated Boltzmann distribution from each method was able to compute the steady-state polarizations with a very high degree of accuracy, with the simulated annealing algorithm producing the best results.     

基于元胞自动机的流域水土流失时空动态变化研究

本文提出一种结合元胞自动机的区域水土流失预测模型,采用线性神经网络方法预测区域土地利用总体变化趋势;同时考虑道路、商服中心对城市土地利用覆盖的影响,制定元胞自动机转换规则,预测区域未来土地利用覆盖情况,预测精度达到72%。最后,将CA预测数据作为变量输入通用土壤流失方程,预测区域水土流失情况。并以武汉市东湖流域为例对其水土流失问题进行了现状分析及预测,为其水土流失整治提供参考。     

Development of IR-emitting colloidal II-VI quantum-dot materials

The current state-of-the-art of colloidal II-VI nanocrystal formation using the aqueous/thiol synthesis route is described. Work on single component and heterostructures and mixed compound quantum dots is discussed. The purpose of the work is to provide a range of infrared (IR)-emitting materials with high quantum efficiency (QE) as potential gain media for future ultrawideband optical amplifiers for high-capacity wavelength-division multiplexing (WDM) telecommunications systems. Physical and chemical factors influencing particle sizes are described     

Simulation of tree propagation in polyethylene including air void by using cellular automata: The effect of space charges

In the present paper tree propagation in polyethylene is simulated with the aid of cellular automata. The case of small air voids is studied for various space charge values. The influence of positive space charge is investigated and the simulation shows that tree propagation is strongly affected by the space charge density. The role of homocharges in the propagation of tree structures is studied and the results of the simulation are in qualitative agreement with published experimental data.     

Lasing characteristics of self-formed quantum-dot lasers withmultistacked dot layer

Room-temperature continuous-wave (CW) operation at the ground state has been achieved in self-formed quantum-dot lasers with multistacked dot layer. By systematic investigation, discontinuous shifts of lasing wavelength from the high-order subbands to the ground state are clearly demonstrated for the first time by varying the number of dot layers and the cavity loss. Lasers oscillating at different subbands exhibit different behaviors against temperature both in the spectral characteristics and in the threshold currents, which are strongly related to emission efficiency of quantum dots and thermal excitation of carriers to higher order subbands. High characteristic temperature over 300 K has been achieved in a laser with high-reflection coating on both facets in the temperature range 60-200 K. Future prospects of improvement in the laser characteristics are also discussed     

基于FPGA的晶闸管数字触发器

介绍了将用在中国环流器2号A（HL-2A）装置磁场电源系统中的晶闸管数字触发器,阐述了其工作原理。利用自适应预测技术克服了同步输入信号的频率变化和畸变对触发器性能的影响和干扰。     

A Fundamental Study on Nonvolatile Ferroelectric FPGA

A new conception on non-volatile ferroelectric FPGA (NVFeFPGA) was proposed in this paper, which is based on FeRAM-Programming, instead of SRAM. Two different nonvolatile configuration storage cells are put forward, according to configuration the logic elements and the routing switches respectively. And three main elements of FPGA are also constructed and considered for nonvolatility.     

基于FPGA的嵌入式逻辑分析仪设计

介绍了一种基于FPGA的嵌入式逻辑分析仪的工作原理,给出了它的部分控制信号的仿真结果.该分析仪不仅自成系统,还可以嵌入到其它系统当中,且其形成的移植性高的IP核可以根据需要方便地植入到别的器件中,使其具备逻辑分析功能.分析仪既可以现场测试,又可以进行远程监控测试.     

一种新的基于FPGA的多路SPWM波形发生器

多电平技术的发展,要求高性能的多路SPWM控制器.有学者提出用DSP和FPGA联合产生多路SPWM的方法,但其过分地依赖DSP,并且整个系统复杂,工作效率低.针对这一情况,提出一种完全由FPGA产生多路SPWM波形的方法,并在Altera的FPGA中得以实现.通过对存储在FPGA中的正弦波数据和三角波数据的比较,产生24路SPWM波形,通过改变时钟频率,来实时调节SPWM波形的输出频率,利用内部分频器,方便调节死区时间和载波频率.该发生器可独立工作,也可和DSP等上位机协同工作,还可作为IP核嵌入到其他系统中.设计中采用优化的思想,既节省了芯片的资源,又提高了芯片的效率.实验与仿真证明,该控制器简单、高效,易于实现,方便产生任意个数的SPWM波形.     

一种基于FPGA技术的图像采集系统

本文介绍了一个基于ＦＰＧＡ （Ｆｉｅｌｄ Ｐｒｏｇｒａｍｍａｂｌｅ Ｇｒｒａｙ，现场可编程六陈列）技术的、精度为８位、６４０×５１２图幅的黑白图像采集系统。系统的采样控制逻辑集成在一块ＦＰＧＡ芯片上。同用通用器件实现的控制电路相比，器件速度快、技术性能更佳，而且设计的灵活性大、系统可靠性提高、体积减小、功耗降低，可以满足高性能的图像采集要求。