A modified particle swarm optimization via particle visual modeling analysis

A particle is treated as a whole individual in all researches on particle swarm optimization (PSO) currently, these are not concerned with the information of every particle’s dimensional vector. A visual modeling method describing particle’s dimensional vector behavior is presented in this paper. Based on the analysis of visual modeling, the reason for premature convergence and diversity loss in PSO is explained, and a new modified algorithm is proposed to ensure the rational flight of every particle’s dimensional component. Meanwhile, two parameters of particle-distribution-degree and particle-dimension-distance are introduced into the proposed algorithm in order to avoid premature convergence. Simulation results of the new PSO algorithm show that it has a better ability of finding the global optimum, and still keeps a rapid convergence as with the standard PSO.     

啤酒糖化过程微机自控系统

针对啤酒糖化过程工艺控制水平的重要性,介绍了微机自动控制系统的结构、功能、控制关键及系统运行效果。     

基于划分策略和填充曲线的抖动模式研究

抖动处理是计算机图形学和图像处理中的一项关键技术,抖动算法的好坏直接关系互图像打印质量的优劣,针对利用评价函数生成较大抖动模式比较困难的问题,提出了划分初始模式的方法,并渐进生成较大抖动模式,针对模式抖动中出现的边界赝象,引入填充曲线机制加以消除,实验表明,采用以上方法得到的结果比较令人满意。     

一种新的CMOS组合电路最大功耗快速模拟方法

过大的峰值功耗会使芯片承受过大的瞬间电流冲击,降低芯片的可靠性及性能,因此有效地对电路最大功耗做出精确的估计非常重要。由于在实际电路中存在的时间延迟,而考虑延时的电路功耗模型计算量较大,因此用模拟方法求取电路最大功耗非常耗时。为了在尽可能短的时间内对VLSI电路的最大功耗做出较为可信的估计,首次提出了二阶段模拟加速方法。对ISCAS85电路集的实验结果表明,这种估计方法具有最大功耗估计值准确和加速明显的优点。     

基于Delphi的微机数据采集监测系统开发

计算机对化学实验数据进行实时采集和处理具有效率高和可靠性好等优点 ,以往采用单片机、PLC系统的较多 ,为了改进系统的设计 ,采用自行设计的小信号调理接口板、智能数据采集模块、RS - 485网络与微机连接的硬件设计 ,以及先进的Delphi语言和面向对象的软件开发技术 ,成功地开发出一种通用、任意通道的微机数据采集监测系统。该系统通用性和扩展性好 ,可以进行多通道、远距离的数据采集。系统硬件、软件和网络结构设计灵活 ,功能强大 ,首先在 72 1型分光光度计上得以成功应用 ,并可广泛应用于多种化学实验和相关科学研究与教学中     

Theoretical and evolutionary parameter tuning of neural oscillators with a double-chain structure for generating rhythmic signals

A neural oscillator with a double-chain structure is one of the central pattern generator models used to simulate and understand rhythmic movements in living organisms. However, it is difficult to reproduce desired rhythmic signals by tuning an enormous number of parameters of neural oscillators. In this study, we propose an automatic tuning method consisting of two parts. The first involves tuning rules for both the time constants and the amplitude of the oscillatory outputs based on theoretical analyses of the relationship between parameters and outputs of the neural oscillators. The second involves an evolutionary tuning method with a two-step genetic algorithm (GA), consisting of a global GA and a local GA, for tuning parameters such as neural connection weights that have no exact tuning rule. Using numerical experiments, we confirmed that the proposed tuning method could successfully tune all parameters and generate sinusoidal waves. The tuning performance of the proposed method was less affected by factors such as the number of excitatory oscillators or the desired outputs. Furthermore, the proposed method was applied to the parameter-tuning problem of some types of artificial and biological wave reproduction and yielded optimal parameter values that generated complex rhythmic signals in Caenorhabditis elegans without trial and error.     

上下同心干 奋力搞攻坚 靖西天然气管道建设大步推进

从天然气开发与利用，建设靖西管道的重大意义；全省上下同心协力，大打管道建设攻坚战；实行军民共建，既打经济仗，又打政治仗；指挥部实施有力领导，确保工程建设顺利进行等方面，在理论与实践的结合上进行了分析研究。     

群体机器人觅食任务Eulerian建模与分析

为了提高觅食任务性能,根据蚂蚁觅食原理引入了觅食概率的概念,机器人按照该概率决定是否离开Home区域,通过改变该概率值来调整环境中机器人的数量。为了研究觅食概率对系统性能的影响,利用Eulerian数学建模方法建立了觅食任务模型,并通过仿真实验分析了觅食概率对系统整体性能的影响。实验结果表明:觅食概率越大,环境中机器人数量越增加,机器人之间的干扰也增加,从而降低系统性能。最后通过实验分析给出了觅食概率与环境中任务数量以及机器人数之间的大致关系。     

Phase formation and modification of corrosion property of nitrogen implanted Ti-Al-V alloy

In the present investigation, polished samples were implanted with nitrogen ion at an energy of 60 keV and implantation doses were 1×10¹⁶, 5×10¹⁶, 1×10¹⁷ and 6×10¹⁷ ions/cm². Glancing incidence X-ray diffraction was employed on the implanted specimens to understand the phases formed with increasing dose. The valence states of nitrogen, titanium and carbon on the sample surfaces were analyzed by X-ray photoemission spectroscopy. The corrosion resistance was examined by the electrochemical methods in a solution with pH=10 at room temperature in order to determine the optimum dose that can give good corrosion resistance in a simulated nuclear reactor condition. Scanning electron microscopy was used to observe the topographies of nitrogen-implanted Ti-Al-Zr after potentiodynamic measurement. It was found that implanted nitrogen dissolved in titanium matrix with increasing dose and the resultant nitrides such as TiN and Ti₂N precipitated. Implantation of nitrogen ions into the surface of Ti-Al-V alloy improves its corrosion resistance, and the increase of the corrosion resistance depends on the nitrogen dose employed; the maximum improvement of the corrosion resistance was observed at a dose of 1×10¹⁷ N⁺/cm².     

冶金期刊关键词标引简析

论述了科技论文中的关键词在标引前需对论文进行主题分析，确定标引要点。分析冶金类期刊关键词标引中易出现的有代表性的问题。