ten is very difficult, On the other hand, the horizontal axis shows a
estimated value by using the multiple regression analysis; in figure (a), the rate of
deviation to the forward direction and to lateral direction were chosen as the independent
variables in meter/minute. Of course these deviation occur corresponding to a magnitude of
maneuver for preventing a collision and can be observed externally as a physical load. In
figure (b), the blocking coefficient which is the largest in each experiment was added
furthermore as a independent variable to express a mental load. Since the number of
independent variables are different, the multiple correlation adjusted by degrees of
freedom is written in both figure as R'.
Whether a mental load of a navigator was evaluated or not is a point of
difference of two figures and a sufficient result was obtained, Especially, the case that
a target came near to an own ship because of too late maneuver to prevent a collision was
included in the experiments and this case disturbs the relation between a physical load
and a subjective evaluation, however, a improved result can be obtained in such a case
when a mental load was taken into account.
Fig.9 The comparison with the subjective difficulty obtained
from the experiment using a ship handling simulator
and the estimated values by the multiple regression analysis.
5. CONCLUSION AND FUTURE EDUCATION SHOULD BE
In order to assess maritime traffic environment and to expansively
develop into absolute evaluation from relative comparison, the model which can reflect a
mental load of a navigator is necessary. Then the maneuvering space concept is a useful
method.
As a further discussion, since the maneuvering space concept reflects
an internal decision making process of a navigator, it can be applied to a latest
integrated navigation system, like an INS or an IBS, as a module to decide the optimum
course and speed to prevent a collision automatically and actually these researches are
carrying out.
Technology concerned with navigation is rapidly advanced in many
fields. So, how
