Fault tree analysis on kinematic accuracy of wafer stage using BDD and DFTA technique
Based on the structure and operation mechanism of the dual-stage lithographic system, fault tree analysis for the key subsystem, wafer stage, is performed. Since the system is very complexity, the BDD (binary decision diagram) and DFTA (dynamic fault tree analysis) technique are introduced to make up the disadvantages of the traditional static FTA (fault tree analysis) method. Event “The kinematic accuracy of wafer stage can't meet the goal” is installed as the top event of the fault tree. Central factors affecting the kinematic accuracy of the wafer stage is identified through the study.
Application of Binary Decision Diagram BDD to the Network Call Fault Analysis
针对移动网络通话问题日益严重,需要建立一个故障树分析(FTA)模型.利用 BDD 技术分析各个基本事件的结构重要度、概率重要度和临界值重要度.基本事件的排序对故障树生成的 BDD 节点个数有直接影响,以及节点的结构重要度和概率重要度都有影响.采用相邻底事件优先排序法,能够尽量减少 BDD 节点个数和对重要度的影响.利用 BDD 法比传统 FTA 法计算的重要度数值更接近,计算效率更高.
Corrosion behaviour of layers obtained by nitrogen implantation into Boron films deposited onto iron substrates
Abstract The electrochemical behaviour and corrosion resistance of boron films deposited onto Armco iron after bombardment with 100 keV N+ ions were determined in various test solutions. The changes in the electrochemical parameters give evidence of lower anodic dissolution rates for the treated samples. Scanning electron microscopy and Auger analysis of the corroded surfaces confirm the presence of protective layers.