Mathematical Approaches in Functional Safety Assessment for E/E/PE Safety-Related Software

Safety integrity level (SIL)-based functional safety assessment is widely required in designing safety functions and checking their validity of electrical/electronic/programmable electronic (E/E/PE) safety-related systems after being issued IEC 61508 in 2010. For the hardware of E/E/PE safety-related systems, quantitative functional safety assessment based on target failure measures is needed for deciding or allocating the level of SIL. On the other hand, IEC 61508 does not provide any quantitative safety assessment method for allocating SIL for the software of E/E/PE safety-related systems because the software failure is treated as a systematic failure in IEC 61508. We discuss the needfulness of quantitative safety assessment for software of E/E/PE safety-related systems and propose mathematical fundamentals for conducting quantitative SIL-based safety assessment for the software of E/E/PE safety-related systems by applying the notion of software reliability modeling and assessment technologies. We show numerical examples for explaining how to use our approaches.

Quantitative Safety Assessment Based on Risk in Level-Crossing between Railway and Highway

In this paper, a portable integrated ship monitoring command system is designed to meet the needs of automatic maritime security working, remote monitoring and commanding ship, while adapting the harsh working environment. The propose ship monitoring command system has merits of ease of installation, highly-integrated features, easy-to-use, and so on. Application of Beidou Navigation Satellite System's high precision positioning and SMS(Short Messaging Service) communication technology in integrated ship monitoring command system can well solve the problem of ship navigation and positioning, remote monitoring and commanding. In our system, ECDIS( Electronic Chart Display and Information System) is chosen as the display platform, HF(High frequency), VHF(Very high frequency) and Beidou is chosen as the communicational measure, Beidou and GPS is chosen as the positioning measure. With the help of the above measures, the static and dynamic data of ship, real-time voice and text are transported to realize the function of ship positioning, ship navigation, remote monitoring and commanding.

Application of the Mond Index in the Safety Assessment of Obsolete Solid Rocket Motor Pretreatment

Security is the first requirement of obsolete solid rocket motor pretreatment. In response to this requirement, quantitative safety assessment of four units in the pretreatment of obsolete solid rocket motor was carried out by using ICI Mond Index; risk rating of each unit was obtained and weak links in the pretreatment security were analyzed; and then appropriate safety measures were proposed, providing scientific guidance for the safety of obsolete solid rocket motor pretreatment.