System and method for perceiving outcast in group

A method of perceiving an outcast in a group from a system for perceiving an outcast in a group, the system comprising a plurality of member terminals held, respectively, by a plurality of members conducting an outdoor activity to transmit waves with a radio frequency, and a leader terminal held by a leader of the outdoor activity, the method comprising:

• receiving, using the leader terminal, the waves transmitted from the plurality of member terminals;
• sensing intensities of the received waves;
• obtaining distances between the plurality of member terminals from the sensed intensities of the waves;
• calculating a group distance based on the obtained distances between the plurality of member terminals;
• forming at least one subgroup with member terminals having a distance between the member terminals within the calculated group distance among the plurality of member terminals to thereby subdivide the plurality of member terminals into the at least one subgroup, which includes adjacent member terminals located within the calculated group distance with respect to one another;
• and
• determining an outcast member terminal by determining whether an unattached member terminal excluded from the at least one subgroup is present among the plurality of member terminals,
• wherein the calculating of the group distance comprises:
• calculating distances between each of the plurality of member terminals with respect to another one or with respect to the leader terminal, and an average distance of the distances between the plurality of member terminals based on the determined distances of the plurality of member terminals;
• and
• calculating a group distance to be proportional to the average distance,
• wherein the determining the outcast member terminal comprises:
• measuring a period of time over which the unattached member terminal is excluded from the subgroup;
• determining whether a ratio of the period of exclusion to a total period of the outdoor activity is greater than or equal to a preset reference ratio;
• and
• determining the unattached member terminal to be an outcast member terminal when the ratio of the period of exclusion to the total period of the outdoor activity is greater than or equal to the preset reference ratio,
• wherein in the step of calculating of the period of exclusion, in a time section when all of the plurality of member terminals are included in one subgroup or a ratio of the unattached member terminal to the plurality of member terminals is greater than or equal to a preset ratio, the period of exclusion is not measured during the time section, and the time section is excluded from the total period of outdoor activity.