Il Moon

Verification method has been developed for determining the safety and operability of programmable logic controller (PLC) based systems. The method automatically checks sequential logic embedded in PLCs and provides counterexamples if it finds errors. The method consists of a system model, assertions, and a model checker. The model is a Boolean-based representation of a PLC's behavior. Assertions are questions about the behavior of the system, expressed in temporal logic. The model checker genera

Abstract Clarke et al. (1986) have developed a model‐based verification method and have applied it to validation of VLSI circuits. We have used the method to test automatically the safety and operability of discrete chemical process control systems. The technique involves: (1) a “system model” describing the process and its software; (2) “assertions” in temporal logic expressing user‐supplied questions about the system behavior with respect to safety and operability; and (3) a “model checker” th

This paper reviews recent contributions on the liquefied natural gas (LNG) value chain in the field of process systems engineering (PSE). While previous review articles deal with specific topics for each issue on the LNG value chain, this paper deals with the key issues and challenges on the LNG value chain from the process systems engineering point of view. The major challenges for the LNG value chain are (a) multiscale and integrated modeling between the liquefaction process and the utility sy

This study focuses primarily on improving large-scale hydrogen liquefaction process by integrating liquefied natural gas (LNG) stream to utilize LNG cold energy. For the hydrogen liquefaction process, a large amount of energy is required for the compression and the cryogenic refrigeration system. LNG is one of the main sources for producing hydrogen, and it can be an opportunity to save energy because LNG cold energy is normally discarded into seawater during regasification. The objective of thi