Comparison of estimated and self-reported basic reproduction number of common cold per day.

, person/day.
, person/day.
Di is the assumed number of common cold infections in winter under different self-reported incidence rate, times. i indicates common cold incidence. i = 1, 2, 3. 1-common cold less than 6 times in the previous 12 months; 2-common cold 6-10 times; 3-comon cold more than 10 times. We assume D1 = 3; D2 = 6; D3 = 8.
Oj is the occupancy level, person/room. j indicates occupancy level. j = 3, 4, 6. 3-three people per dorm room; 4-four people per dorm room; 6-six people per dorm room.
Di,j is the proportion of students with different self-reported common cold incidences, %.
M is the duration of a common cold, days. We assume M = 9 days [1].
T is days in winter season, 120 days.
Cj is the average CO2 concentration from 1:00 a.m. to 8:00 a.m. in rooms with different occupancy levels, ppm.
fj is the re-breathed fraction of indoor air in rooms with different occupancy levels. fj = (Cj-C0)/Ca. Ca is the volume fraction of CO2 added to exhaled breath, 37000 ppm. C0 is the volume fraction of CO2 in outdoor air, 300 ppm.
q is the quantum generation rate by an infected person, quanta/h. We assume q = 9 quanta/h [25].
t is the time a infector remaining in the dorm room, hour/day. We assume t = 8 hours per day.