小世界理论在蠕虫传播机制中的应用研究

首先介绍了小世界理论的概念及其在互联网商业领域中的应用成果。接着分析了小世界理论在蠕虫研制中的应用问题，将实际生活中互相联系的某些潜在攻击目标之间，通过小世界效应产生聚合，最终产生一个可信任的目标网络。利用文章所述的目标网络构建和分析方法，可以清晰地描绘出蠕虫内部传播的网络结构。     

冷轧硅钢横向同板差优化方案研究

对冷轧硅钢横向同板差的影响因素进行了研究。利用6 Sigma的研究方法,开展DOE实验方案设计,得到同板差与4个变量的回归模型。通过对模型中各变量进行优化,得到同板差最优值。在满足客户对同板差要求的前提下,可根据热轧平均凸度,对中间辊窜辊、辊型进行优化,以减少冷轧切边量、避免切边浪费、提高硅钢综合成材率。     

基于六西格玛的电池组自动焊合格率改善策略

通过电池组自动电阻焊的实验研究,采用六西格玛理论分析出对自动电阻焊缺陷最显著影响因素,并针对不同的电阻焊缺陷提出改进措施。从改善后的FEMA看,各种影响电池组焊接缺陷的因素有很大改善,电阻焊后续制程在手动转自动化过程中,需要采用六西格玛的方法进行质量控制与分析,最终采取适当的改善措施,实现电池组自动电阻焊的质量可靠性保证。     

热压快速凝固Fe0.92Mn0.08Six半导体的热电性能

采用快速凝固和热压的方法制备了p型热电材料Fe0.92Mn0.08Six(x=1.9, 2.0, 2.1, 2.3, 2.5).X射线衍射分析表明,热压试样退火24 h后,完全转变为β半导体相.所有试样的致密度均高于90%.测量试样的电学性能发现,原料配比为Fe0.92Mn0.08Si2.1的试样在整个测量温度范围内的功率因子最大,550℃时达到了400 μW·m-1·K-1以上.     

Evaluating Six Sigma failure rate for inverse Gaussian cycle times

Six Sigma is a quality philosophy and methodology that aims to achieve operational excellence and delighted customers. The cost of poor quality depends on the sigma quality level and its corresponding failure rate. Six Sigma provides a well-defined target of 3.4 defects per million. This failure rate is commonly evaluated under the assumption that the process is normally distributed and its specifications are two-sided. However, these assumptions may lead to implementation of quality-improvement strategies that are based on inaccurate evaluations of quality costs and profits. This paper defines the relationship between failure rate and sigma quality level for inverse Gaussian processes. The inverse Gaussian distribution has considerable applications in describing cycle times, product life, employee service times, and so on. We show that for these processes attaining Six Sigma target failure rate requires higher quality efforts than for normal processes. A generic model is presented to characterise cycle times in manufacturing systems. In this model, the asymptotic production is described by a drifted Brownian motion, and the cycle time is evaluated by using the first passage time theory of a Wiener process to a boundary. The proposed method estimates the right efforts required to reach Six Sigma goals.     

欧盟RoHS指令在洗衣机产品中的实践

本文简要介绍了RoHS指令要求及在国内外的落实和进展情况,详述了该指令的实施步骤及过程,针对海尔洗衣机产品在落实RoHS指令中遇到的一些问题和难点进行了分析、讨论,文中给出了一部分零部件具体详实的测试数据,做必要的对比说明,并肯定了这一新技术要求在洗衣机产品中全面落实是可行的。     

空间对接综合实验台Stewart运动平台轨迹规划的研究策略

介绍空间对接技术和Stewart运动平台的概念,说明目前研究空间对接仿真技术对我国具有重大意义,探讨国内外空间对接系统运动学动力学建模、半物理仿真和路径规划的研究现状,更进一步深入分析了对接综合实验台stewart平台的轨迹规划研究策略和途径.     

Real-time contactless measurement of robot pose in six degrees of freedom

For dynamically measuring position in three degrees of freedom laser tracking systems are well known. Up to now no possibility to measure also orientation using the same laser beam has been known. We present a technique to incorporate orientation measurement into a laser tracking system that requires only minor changes in the existing hardware. The method is based on the analysis of an image of the reflected laser beam intensity distribution. In this image the edges of a slightly modified retroreflector represent a function of the orientation of the end-effector holding the retroreflector. It is shown that from this image the orientation can be determined uniquely and in real time.

A laser tracking system including position and orientation measurement constitutes an instrument to accurately determine robot performance as well as to acquire hints on how to improve robot models and control algorithms.     

Six Sigma experience as a stochastic process

This study empirically investigates the states of Six Sigma from a stochastic point of view. By the means of an advanced survey, 97 respondents are asked to rate the effect of Six Sigma on different performance categories, the cost of implementing Six Sigma, the level of enthusiasm and expectations from Six Sigma over 20 years. The autocorrelation and cross-correlation functions of these processes are analyzed to investigate the stages of Six Sigma. Consequently, new concepts namely steady state of Six Sigma and Six Sigma experience functions are introduced which shed light on the life cycle of Six Sigma within the companies.     

Adaptive integral feedback controller for pitch and yaw channels of an AUV with actuator saturations

Input saturations and uncertain dynamics are among the practical challenges in control of autonomous vehicles. Adaptive control is known as a proper method to deal with the uncertain dynamics of these systems. Therefore, incorporating the ability to confront with input saturation in adaptive controllers can be valuable. In this paper, an adaptive autopilot is presented for the pitch and yaw channels of an autonomous underwater vehicle (AUV) in the presence of input saturations. This will be performed by combination of a model reference adaptive control (MRAC) with integral state feedback with a modern anti-windup (AW) compensator. MRAC with integral state feedback is commonly used in autonomous vehicles. However, some proper modifications need to be taken into account in order to cope with the saturation problem. To this end, a Riccati-based anti-windup (AW) compensator is employed. The presented technique is applied to the non-linear six degrees of freedom (DOF) model of an AUV and the obtained results are compared with that of its baseline method. Several simulation scenarios are executed in the pitch and yaw channels to evaluate the controller performance. Moreover, effectiveness of proposed adaptive controller is comprehensively investigated by implementing Monte Carlo simulations. The obtained results verify the performance of proposed method.