Eun-kyung Ji

Medical cyber-physical systems (MCPS) are life-critical, context-aware, networked systems of medical devices. These systems are increasingly used in hospitals to provide high-quality continuous care for patients. The need to design complex MCPS that are both safe and effective has presented numerous challenges, including achieving high assurance in system software, intoperability, context-aware intelligence, autonomy, security and privacy, and device certifiability. In this paper, we discuss the

Rigorous quality demonstration is important when developing safety-critical software such as a reactor protection system (RPS) for a nuclear power plant. Although using formal methods such as formal modeling and verification is strongly recommended, domain experts often reject formal methods for four reasons: there are too many candidate techniques, the notations appear complex, the tools often work only in isolation, and output is often too difficult for domain experts to understand. A formal-m

Formal verification of Function Block Diagram (FBD) based software is an essential task when replacing traditional relay-based analog system with PLC-based software in nuclear reactor protection system (RPS). FBD programs are developed manually and revised frequently in process of development. There are a set of properties to be verified formally, which all FBD releases should satisfy. Whenever FBDs are modified, there is also a need to verify behavioral equivalence of subsequently modified FBDs

Guaranteeing timing properties is an important issue as we develop safety-critical real-time systems such as cardiac pacemakers. We present a safety assured development approach of real-time software using a pacemaker as our case study. Following the model-driven development techniques, measurement-based timing analysis is used to guarantee timing properties in implementation as well as in the formal model. Formal specification with timed automata is checked with respect to timing properties by

A blockchain is a type of distributed ledger that can record transactions between parties in a verifiable and permanent manner. Each node contains its ledger, and the contents of each ledger are maintained to be the same by a consensus algorithm. It is essential to ensure the safety and liveness of the consensus algorithms in blockchain platforms. The Stellar Consensus Protocol (SCP), which is a consensus algorithm for the Stellar cryptocurrency using the blockchain, is utilized for the federate

SUMMARY Automated and effective testing for function block diagram (FBD) programs has become an important issue, as FBD is increasingly used in implementing safety‐critical systems. This work describes an automated test case generation technique for FBD programs and its associated tool—FBDTester. Given an FBD program and desired test coverage criteria, FBDTester generates test requirements and invokes the Satisfiability Modulo Theories solver iteratively to derive a set of test cases. An industr

Model checking is often applied to verify safety-critical software implemented in programmable logic controller (PLC) language such as a function block diagram (FBD). Counter-examples generated by a model checker are often too lengthy and complex to analyze. This paper describes the FBDVerifier which allows domain experts to perform automated model checking and intuitive