Reliability Analysis of Safety Grade Programmable Logic Controller
This paper focuses on the random hardware failures necessary for the safety assessment of the reactor protection system (RPS). A prediction method of the hardware failure rate for safety assessment is suggested, and applied to the safety grade programmable logic controller (PLC) to identify design weak points from a safety point of view
Designing a Dangerous Location Aware Service Using Space-Oriented Metadata
Detecting dangerous locations/sites is becoming an important objective necessary for many human life assisting services. To access human living surroundings, it requires many computation costs since our living space includes many kinds of elements (e.g. factors, subjects, targets and more that locate in our living space). The concept of space-oriented metadata is an effective data modeling approach to reduce the complexity of structural access management. As XML becomes a key format both for data representation and transactions, the data used in our research is taken from the real world, where the content is a mix of location and dangerous event information. We add some features into the space information in order to deal with, and take advantage of, various user properties, such as metadata. This technique enables us, for instance, to offer efficient location aware services. This paper focused on space-oriented metadata, management methods and introduces a new architecture to include these major context processing parts into the Ubickids project prototype application
A model for battery pulsed discharge with recovery effect
This paper introduces a stochastic model of battery behavior, that emulates electrochemical mechanisms that are key to battery performance under pulsed discharge conditions. A pulsed discharge allows charge recovery during the idle periods. Recovery depends on the state of charge of the battery and on the duration of the rest time period. Using the postulated model, we derive the improvement to battery lifetime that results from pulsed current discharge driven by bursty stochastic transmissions. The results emphasize the role of traffic shaping in the quest to enhance battery behavior.