本项目以Signature为主要工具，紧抓以往可靠性理论研究中相对欠缺的两个重要元素—系统结构的一般性与元件寿命的相依性，开展相依系统可靠性与安全方面的研究。主要研究内容包括：Signature的有效计算方法和年龄性质；具有一般结构的相依系统随机性质和可交换系统的元件冗余优化问题；具有一般结构的目标攻击相依系统防御问题。本项目旨在（1）以Signature为系统结构的描述，建立一般相依系统下元件寿命和系统结构对系统可靠性的影响机制；（2）建立以Signature及其相关量为优化目标的可交换系统最优元件冗余策略；（3）建立以Signature为系统结构描述，以Copula为攻击相依描述的目标攻击相依系统最优防御策略研究框架； (4)建立Signature的有效计算方法和年龄性质，扩展Signature在可靠性理论中的应用范围。

This project employs the tool of Signature in the investigation of relevant issues of reliability and safety of generalized dependent systems, with emphasis on generalized structure and dependence between components. The contents of the study include the computation methods and ageing properties of Signature, the stochastic properties of dependent systems with general coherent structures and the optimizing redundancy policies of exchangeable systems, as well as optimizing defense strategies of dependent targets. On the whole, the purposes of this project are to establish the mechanisms of impacts of the structure and the lifetimes of components on the system reliability with Signature representing the system structure, to create the optimizing redundancy policies of exchangeable systems with the aim of maximizing the Signature and other related quantities, to develop the framework on the optimizing defense strategies of dependent targets with Signature representing the system structure and Copula modeling the dependence of attacks, and to expand the application of the Signature in Reliability Theory by exploring the effective computation methods and aging properties of Signature.