In recent years, Autonomous Surface Vehicles have secured the focus of major research and industrial initiatives around the world. Following this trend in the wake of fourth industrial revolution of oceans, Marine Autonomous Surface Ships (MASS) have become the focus of numerous research. In order to shift from conventional ships to autonomous transportation, manoeuvring data collected through real-ship trials have to be available, and analysed. In this study, manoeuvring characteristics of a real ship were studied over a period of three years, data were collected and analysed to identify changes of manoeuvring characteristics over time. Real-ship data were then compared with simulation data to validate a manoeuvring simulator program. Through the real-ship experiments, not only the simulation results were validated, but also the possibility of predicting ship manoeuvrability using simulations in controlled environments was identified. In addition, the importance of accumulation of manoeuvring data in helping future designs of ships with similar characteristics is identified.

This study aims to measure the indoor radon concentration (IRC) of 56 radiation areas at 34 medical institutions to assess their adequacy as required by the South Korean Ministry of Environment and international standards, and calculate the annual effective dose (AED) of individuals in radiation-related professions at each medical institution. The study was conducted for 9 months and the AED was calculated according to the South Korean Nuclear Safety and Security Commission’s equation. The environmental factors that can affect IRC were analyzed by medical institution, floor level, province and ventilation system. The IRC of eight radiation areas exceeded the recommendation of the International Commission on Radiological Protection, with max-AED and min-AED showing a difference of 1.42 mSv/y. Therefore, all radiation areas that exceed the recommended limits must set up preventative measures to minimize exposure. Furthermore, a systematic management plan involving the issuance of radon test reports is required.