The 2020 SO_X regulation based on MARPOL73/78 requires ships to use low-sulfur fuel oil or to install exhaust gas scrubbers. In this study, PM emitted from ships before and after fuel oil conversion was collected by actual ship experiments, investigated the characteristics of the main components of PM, and found that by using low-sulfur fuel oil(Diesel oil, JIS A), SO₄^2- emission rate decreased 98.8 % on average, OC emission rate decreased by 26 % on average, and PM emission rate decreased by 79 % on average. Furthermore, we also investigated the operational data of the ships when they were collected, and examined the differences in the operational areas of the ships. In addition, we observed changes before and after fuel oil conversion from the values of atmospheric PM2.5 V, Ni concentrations and V/Ni ratios measured at onshore facilities.

An automatic lookout system is very important to realize autonomous navigation of ships. Many kinds of sensors such as radar, GNSS (Global Navigation Satellite System), IMU (Inertial Measurement Unit) and AIS (Automatic Identification System) are required for the autonomous navigation system. In addition to that, visual sensors are very useful to recognize the situation around the own ship. In particular, stereo cameras can provide the distance information of the surrounding objects such as other ships, buoys, breakwaters, bridges and other obstacles. This paper proposes a novel method to calibrate a wide baseline stereo camera system to measure 3D locations of long-distance targets. An experiment measuring locations of other ships using onboard stereo cameras indicates that distances to the other ships can be measured within an error of 10 % for 1,000 meters ahead and 20 % for 2,000 meters ahead.

To reduce CO₂ emissions from ships, efforts are being made to electrify and hybrid ship propulsion systems. By newly mounting a battery as a power source, zero emission at a port of entry or departure is realized by the energy of the battery, and zero emission in a ship during cargo handling is realized by the energy of the battery. However, the kinetic energy of the hull has not yet been effectively utilized by regenerating electric power. we obtained 12% regeneration energy amount at the time of entry and 5.66% regeneration amount at the time of departure when the opportunity of energy regeneration is not expected by the experimental analysis. This paper clarifies what kind of operation should be carried out to charge batteries and enter the port in order to cover all necessary energy at the time of departure with regenerative energy. The energy quantity required for the departure and the maximum power output of the main engine at the departure were obtained, and the relation between the power density required for the battery and the energy density was clarified. This paper concretely mentions the feasibility and necessary number of the existing mass-produced EV battery box.