## 2 Materials and Methods
### Experimental Equipment

Table 1: Literature review (source: own compilation based on the [6;7;9]). a mold width of 19.4 m, and a sailing speed of 17.7 knot. The detailed ship specifications are listed in Table 2.  
Ships are equipped with an AMS, loading and unloading systems, and engine room systems. The AMS collects and stores sensor data from each system. Therefore, ship operation data were acquired through the AMS. Two stroke diesel engines are usually used as the propulsion engines of medium sized and large ships because they are advantageous in terms of output and weight considering the size of the ship. The ship to be studied was a medium sized ship with a two stroke diesel engine used as the propulsion engine. The propulsion engine was a six cylinder engine with a cylinder diameter of 400 mm and a cylinder stroke of 1770 mm, and the rated output was 6618 kW. The detailed specifications of the propulsion engine are presented in Table 3.  
The propulsion engine of a ship is operated by an engine telegraph and controlled according to the engine control mode, as shown in Table 4, based on the RPM of the engine to control the ship speed. The control modes are divided into two major modes: the maneuvering mode of dead slow, slow, half, and full, four steps that can quickly control engine loads, such as arrival and departure, and a constant speed navigation mode (cruising mode) of navigation full. As described above, the ship was equipped with a CPP; thus, the pitch of the propeller was simultaneously controlled according to the engine mode. The AMS installed in the engine room of the ship monitors factors such as temperature and pressure that can determine the operation status of mechanical systems, such as engines and pumps. In addition, the AMS is built to control the engine and mechanical systems. Engine monitoring and alarm items (lists) are composed of factors that directly and indirectly affect engine combustion and factors that affect mechanical defects. \begin{table}
\begin{tabular}{c c} \hline \hline
**Description** & **Specification** \\ \hline Gross tonnage & 9196 ton \\ Length overall (L.O.A) & 133.0 m \\ Breadth (Mlb) & 19.4 m \\ Speed (design draft, 85\% MCR with 15\% S.M) & 17.7 knot \\ Range of endurance & 14,500 n.miles \\ Number of people on board & 239 persons \\ Controllable pitch propeller & WARTSILA D 4000 MM \(\times\) 4 blades \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Specifications of the ship used in this study (source: own compilation based on the ship manual). \begin{table}
\begin{tabular}{c c} \hline \hline
**Description** & **Specification** \\ \hline Type & MAN B\&W 6540 ME-B9.5 \\ Rated output & 6618 kW \\ Diameter of the cylinder & 400 mm \\ Stroke & 1770 mm \\ Number of cylinders & 6 \\ Mean effective pressure & 20 bar \\ Maximum cylinder pressure & 185 bar \\ Turbo charger & HYUNDAI-ABB, 1 \(\times\) A165L37 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Specifications of the propulsion engine used in this study [17]. In total, 104 types of data were collected by checking numerical data, such as temperature and pressure, that can be analyzed; these data identify the operating condition of the propulsion engine in the AMS in the engine room. Considering changes in the marine environment and the influence of weather, data from eight voyages (21071, 21081, 21091, 21101, 21102, 21112, 21121, and 21122) acquired from the hot season (July) to the cold season (November) were utilized for this research. In addition, anomalistic symptom data (21123) were established based on the results of a previous study [18] on the implementation of abnormal symptoms using engine simulation and the analysis of abnormal operation items and maintenance determination factors of the engine to verify the anomalistic symptom judgment algorithm.