# Application of Collision Warning Algorithm Alarm in Fishing Vessel's Waterway
## 3 Application of Collision Warning Algorithm to Real Ship Test
### Results of the Real Ship Test  
The results of the real ship test showed the locations at which step-by-step alarms in each scenario were generated in different colors to indicate the alarm-based track. The time at which the step-by-step alarms were generated was analyzed. In addition, one ship was designated as a reference ship. The alarms based only on DCPA and TCPA criteria and those based only on the PARK model risk value criterion were compared with those based on the combination of DCPA, TCPA, and PARK model risk value criteria. 1. Scenario 1  
In scenario 1, ship A and ship B sailed in parallel, while ship C sailed toward them from the opposite direction for approximately 6 min. The results of the analysis are shown in Figure 5 and Table 3.  
Figure 4: (**a**) Scenario 1: ships A and B sail in parallel at a course of \(\sim\)045\({}^{\circ}\) while ship C sails from the opposite direction at \(\sim\)225\({}^{\circ}\) and (**b**) scenario 2: ship A sails at the course of \(\sim\)045\({}^{\circ}\), ship B at \(\sim\)315\({}^{\circ}\), and ship C at \(\sim\)180\({}^{\circ}\), approaching a single location. Figure 5: (**a**) Diagrammatic representation of the track of alarms generated from the test results of Scenario 1 and (**b**) graphical representation of the alarms generated on ship C depending on time (from the top, alarms based only on the DCPA and TCPA criteria, alarms based only on PARK model risk value criterion, and alarms based on the algorithm). Figure 5a shows the alarms generated according to the tracks of the three ships thatailed in accordance with Scenario 1, and Figure 5b shows the graphs of the alarms based only on DCPA and TCPA criteria, those based only on PARK model risk value criterion, and those based only on the algorithm applied in this study, which are all applied to ship C. The figures indicate the alarms based on time so that they can be compared with each other. Table 3 presents the data of the time when the step-by-step alarm was first generated in each ship. As shown in Figure 5a and Table 3, ships B and C encountered each other at 99.3 s after the test started. The alarm criteria were met and the first main alarm was generated continuously in ships B and C owing to the risk value. At 105.1 s, the first main alarm was generated in ship A owing to the risk of collision with ship C; thus, the first main alarm was generated in all three ships. Ships B and C came closer to each other at 161.1 s and the alarm stage changed to the second main alarm that was momentarily generated in ship A at 211.5 s as its alarm criteria with ship B was satisfied. Ships B and C became dangerously close to each other at \(\sim\)254 s, which resulted in a step-by-step alarm. The first main alarm was generated continuously in ship A as it came closer to ship C and was turned off at \(\sim\)240 s. However, because ship A had a temporary encounter with ship B during its encounter with ship C, the second main alarm was generated. As shown in Figure 5b, when only the DCPA and TCPA criteria were applied, the normal situation without alarm generation and the first or second main alarm were indicated alternately, resulting in the generation of noncontinuous alarms. After \(\sim\)200 s, the alarms were not generated despite being under risky situations because the criteria for the alarm conditions could not be met. In the case of applying only the PARK model risk value criterion, the alarms were generated continuously. However, they were generated in the pre-alarm stage, which was triggered even when the two ships were far away from each other and there was enough time to respond to the encounter. Therefore, ship operators would rely less on those alarms. However, the algorithm applied in this study continuously generated an alarm in a step-by-step manner in risky situations and was able to alert ship operators to risky situations when the first and second main alarms were generated alternately. 2.