Ranking of aircraft maintenance organization based on human factor performance

Aircraft maintenance organisation is a complex socio-technical setup, where human factors influence the quality of aircraft maintenance service. Maintenance service quality is assessed based on the commitment of management and its ability to provide suitable facility, tools, spares and manpower supported with comfortable environment and maintenance procedures. Assessment of the service quality of the aircraft maintenance organisation is a complex process. Airlines, regulators, insurance companies and other agencies need decision support system, to assess the performance of a maintenance organisation. This paper provides criteria and scientific approach for assessing the maintenance organisation; it presents a methodology of applying Analytical Hierarchy Process to prioritise the key functions and to rank the maintenance organisations under study. The study has established that maintenance service quality in airline is directly correlated to its fleet size.     

Global stable tracking control of underactuated ships with input saturation

In this paper, tracking control of underactuated ship in the presence of input saturation is addressed. By dividing the tracking error dynamic system into a cascade of two subsystems, the torques in surge and yaw axes are designed separately using the backstepping technique. More specifically, we design the yaw axis torque in such a way that its corresponding subsystem is finite time stable, which makes it to be de-coupled from the second subsystem after a finite time. This enables us to design the torque in the surge axis independently. It is shown that the closed-loop system is stable and the mean-square tracking errors can be made arbitrarily small by choosing design parameters. Simulation results also verify the effectiveness of the proposed scheme.     

基于单片机的时序测试系统设计

针对某特殊应用条件下的时序测试需求,设计了一套基于单片机的测试系统,系统以STC12C2052单片机作为测试的基础硬件,完成逻辑控制、数据采集以及数据处理、测试结果传输等功能,具有结构简单、体积小、性价比高等特点.上位机部分的软件基于VC++6.0设计,主要完成测试数据存储和显示功能.单片机与上位机间通过串口进行通信,经实验证明该系统的测试结果误差较小,工作稳定,完全能够满足实际测试需要,结合上位机能方便的进行历史数据查看和时序波形对比.     

A method for integrating ergonomics analysis into maintainability design in a virtual environment

Designers must consider human factors/ergonomics when making decisions from the perspective of maintainability. As an important aspect of maintainability, maintenance space should be made adequate at the design stage to achieve a convenient maintenance process. A maintenance space evaluation method that considers ergonomics is proposed in this study. By comparing free swept volumes and constrained swept volumes in a virtual environment, maintenance space could be evaluated quantitatively and objectively. The results of the evaluation are obtained by combining the principles of ergonomics and maintainability. These results can help designers improve product design such that it fits ergonomics and maintainability requirements. A case study is introduced at the end of this paper to demonstrate the feasibility of the proposed method in efficiently evaluating the maintenance space based on the layout design of the product components in the design stage.Relevant to industryFor a large number of disasters caused by human errors in current industry, the result of this study contributes a guide to fully consider human factors in maintainability design through virtual environment and is beneficial to designers and engineers of industrial application fields.     

基于体验学习的“过程控制”实验教学设计

"过程控制"是自动化专业的主要专业课程之一,具有专业性和实践性较强的特点。课程不仅涉及许多控制理论知识,而且与工业生产实际紧密联系。实验环节在整个课程中起着十分重要的作用。本文从体验学习理论出发,从知识获取过程的角度对过程控制实验教学环节进行了重新设计和安排,使实验教学过程更符合人获取知识过程的规律。     

激光辐照皮肤组织的光子传输解析计算研究

建立了激光与皮肤组织相互作用的二维非稳态光场模型,在柱坐标系下采用漫射近似法和格林函数法精确求解了高斯和平顶分布的连续激光辐照皮肤组织的光传输方程,得到瞬态光场分布,并以氦氖激光辐照皮肤组织为例,数值模拟了皮肤组织在激光作用下的光分布。研究结果表明：皮肤组织径向光分布规律与入射激光束的光强分布相似,激光与组织光效应在很大程度上取决于激光参数,主要有激光功率、焦斑半径等。     

一种过程与结构结合的数控知识建模研究

数控加工中的知识是指已有的参数、工艺和流程等加工经验的集合,数控加工知识类型繁多,应用背景复杂,不同零件的加工差异较大。本文建立了编程过程与工艺数据结构相结合的知识管理模型,模型构建过程中设计了通用的数控编程模板和知识体表达模板,通过模型的构建,实现了零件数控加工中知识背景的准确描述、知识载体的全面管理以及多类型的知识添加。最后,通过叶轮数控加工过程中的知识管理验证了模型的有效性。     

Substrate integrated waveguide loaded by 3-dimensional embedded split ring resonators

A substrate integrated waveguide (SIW) loaded by three-dimensional embedded split ring resonators (3-DESRRs) is discussed theoretically and experimentally. The 3-DESRR structure which has proved to be an alternative magnetic metamaterial resonator for SIW structures is able to provide negative transversal permeability if excited properly. The 3-DESRR loaded SIW shows a bandpass-like response as an effect of loading the 3-DESRRs in the SIW. The lower and upper band edges of the resulting transmission line (TL) are determined by the SIW cutoff (f_c) and the resonance frequency of the 3-DESRRs, respectively. Finally, a prototype of the proposed 3-DESRR loaded SIW TL is fabricated and tested. The measured results are in good agreement with those obtained by theory and simulation.     

Binary code compression algorithm used for the real time compensation of the modulation error in miniaturized FOG

This paper presents a kind of novel binary code compression algorithm to reduce the size of the signal processing circuit and to realize real time compensation for the modulation error in fiber optic gyroscope (FOG). The disadvantage of general compensation method is figured out firstly. The modulation error is modeled and analyzed with taking the closed-loop characteristics into consideration. The analysis indicates the condition in which the error compensation is effective and real time. Then the compensation algorithm based on binary code compression operation is described. The functional design of the algorithm is realized in a single field programmable gate array (FPGA) by using modular design method, substituting some harewares in signal processing circuit, and system speed is very fast. The simulation and experiment results suggest that the algorithm and implementation is valid. The modulation error is real time compensated in every error detection cycle, and the error compensation resolution is enhanced from 2⁻¹⁰ to 2⁻¹⁶ rad/V.