opyright Nancy Leveson, Sept. 1999 Stage 1: Forming Team members begin to discover what behaviors are acceptable Usually highly unstructured environment Attempt to identify tasks, how to accomplish them Decisions on what information is needed Hesitant participation

Can programming language influence correctness? anguages affect the way we think about problems The tools we use have a profound(and devious) influence on our thinking habits, and, therefore on our thinking abilities?

第一节 X射线的发生与性质 第二节 晶体结构

Reuse (Assume have source code, not a commercial product) Ariane 5. Therac-25. British AtC Expectation Significantly lower development costs and time. Amortize costs among all users or uses Assumptions

Formal design Reviews Associated with each of documentation phases Evaluate with respect to Customer requirements Prescribed standards and practices Contractual requirements

State Machine specifications Define behavior using states and transitions between states

Outline: Software Design Goals History of software design ideas Design principles Design methods Life belt or leg iron?(Budgen)

（一）岩体边坡破坏 的主要类型： 平面滑动

一、应力路径的概念: 二、土体受力发生发展和变化的过程

(一) 自重应力情况 (二) 附加应力情况—孔压系数概念 1 . 侧限应力状态