2.1.2 Real time

　

　In previous section, we pointed important functions of simulator such as quality and quantity of supplied information. We have to consider the other factor. That is time scale of reappearance. As you know, manned model shown in Photo.6 is used for training of mariner and for assessment of navigational environment. Manned model is to simulate real situation by using model ship and model navigational environment in the water. Mariner handles the model ship onboard and maneuvers through the simulated small navigational condition. He can experience the handling situation in this condition. In this case, the responses to steering are correct within model scale. He can know the responses of ship to steering corresponding to model scale. He can understand relative motion to navigational environment. So manned model is useful to understand the maneuverability by observing relative motion to geographical condition in model scale. Necessary items concerning response of steering and geographical environment are reappeared. However, time scale of manned model differs from real situation. The difference occurs following issues,

　

(1) Human's time scale and model time scale

 In case of the issue that the response time is important, the difference of time scale may not be acceptable. For example, quick response to the change of motion is required for unstable ship. In case of Ship-handling requiring big time consumption for human's information processing, the difference may also become issue. If we carry out the training on collision avoiding maneuver using first time simulator, trainee cannot attain the proper handling because he cannot enough process information within allowable time. These trainings are not carried out using manned model. As a result, for the situation in which human's time scale shows big affect, the time scale has to be realized as real world.

　

(2) Conversion of time scale

　Trainee expresses the efficiency of training using manned model. It can be guessed that they understand the time to steer referring to the motion. There is no idea on time progress. The maneuverability is understood through this situation. When they come back to real world and face the situation in which time progress become important factor, they have to convert the time scale. The conversion may impose workload on them.

　

　

 Objectives of simulator application are abstractly categorized as training and assessment of navigational condition. The reasons of these simulator applications are based on the characteristics of reappearance of real situation. The relation between the objectives of simulator application and simulated functions are discussed in this section and next one.

　

 One of simulator application is to use it for training of mariners.[4] The issues on simulator application for training are discussed in Workshop in this MARSIM conference.[5][6] In this paper, the relation between training objectives and simulator functions is mainly discussed.

　

 The objectives of training using simulator are to bring up mariner's competency. In the early stage of simulator application for training, the object was to make mariner familiar to the navigational environments. Today, the objectives of training have became more functional. For the reasons of that the techniques to maintain the safe navigation are important, the discussion on the techniques is needed. The necessary techniques for safe navigation are listed in STCW convention. However, the concrete contents are not indicated. The understanding on the concrete techniques in contents of STCW depends on the instructor in each training institute. To unify the interpretation of STCW and necessary techniques for safe navigation, many discussions have been done in international conferences and unions, such as MARSIM, IMSF, IMLA, INSLC and METNET. As a result of the discussion, the necessary techniques for safe navigation are almost clarified.[7]

　

 The objectives of training are to enhance mariner's competency. The competency is constructed plural ability of relating techniques. Therefore training have to intend to enhance plural kinds of competency. Then the training items relate to objective techniques. As a result, the objective techniques of training should be clarified.

　

 The necessary functions are to reappear the condition and information and they depend on training objectives. Most of trainings intend to bring up the behavior that mariner response suitable action corresponding to specific condition. For instance, when mariner faces the specific navigational situation, firstly he is expected to recognize the present situation. Secondly he has to estimate the future situation and analyze the situation. Then he is expected to carry out suitable action. This process is shown in Fig.1. When we consider the necessary function of simulator from viewpoint of this information processing, simulator functions become clear. For the first stage, simulator has to supplies necessary present information to estimate future situation. Ideally, they are same as real situation but restricted information is also acceptable because mariner has to estimate future situation based on restricted information in some occasions. Any way, in case of restricted condition, necessary information in real situation should be reappeared. Necessary information is clarified by analyzing the training techniques. Secondly, simulator has to install the apparatus to steer the ship or to communicate others. Finally, simulator reappear rational change of situation that is rational estimation of ship motion and change of environment. The changes have to be shown correctly. Using simulator that reappear necessary information mentioned above, instructor of training can teach the rational behavior for mariner.

　

 The capable training items corresponding to training techniques are, decided by the function. Instructor has to know the techniques in training item and to make training items, which can be trained by using his simulator. He has to understand the relation between the necessary information for the training on the techniques and simulator function.

　

 After accomplishing required competency, mariner executes required judgment and required action. Then, required behavior that is done by required competency should be clarified. Competency means 2 kinds of abilities. One is an issue on the knowledge. These are mainly accomplished in classroom and understanding the textbook. The others are the issues how to execute and how to use them in real situation. These are brought up in real situation including simulator training. It is important whether mariner execute a rational behavior defined in required technique when he faces the situation.

　

 Fig. 2 shows the meaning of training and the relation between the simulator function and training. When we assume that human is one kind of control system, mechanical control system output specific response based on specific input shown in Fig. 2-1. On the other hand, mariner not holding sufficient competency shows wide variety of behavior. On the contrary, mariner holding sufficient competency shows similar reaction without wide variation that is required by regulation. In Fig 2-2, the distribution of behavior of mariner not holding sufficient competency shows big variation. After the competency of mariner become sufficient due to training, his behavior reach the required one indicated by "yo" within small variation. In this case, we can consider that inputs correspond to the supplying information to mariner in simulator. When simulator supply insufficient reappearance, mariner think another situation: "xo'" and make different behavior: "yo'" that is assessed as wrong behavior shown in Fig. 2-3. As the input condition corresponds to the necessary function of simulator, the techniques in training are decided within the simulator functions.