Id |
Subject |
Object |
Predicate |
Lexical cue |
T51 |
0-28 |
Sentence |
denotes |
Parameter estimation process |
T52 |
29-220 |
Sentence |
denotes |
Under the gradually enhanced control strategies since January 23rd, 2020, the parameter values with substantial changes include the contact rate, the diagnose rate and the quarantined rate q. |
T53 |
221-347 |
Sentence |
denotes |
Therefore, we fixed the parameter values except these three as the estimated values in our previous study (Tang et al., 2020). |
T54 |
348-485 |
Sentence |
denotes |
The initial contact rate c0 is assumed to be the average contact rate between January 10th, 2020 and January 22nd, 2020, hence c0=14.781. |
T55 |
486-529 |
Sentence |
denotes |
With the same assumption, we set δI0=0.133. |
T56 |
530-676 |
Sentence |
denotes |
Note that, the initial conditions can be obtained by solving our previous model (Tang et al., 2020) from January 10th, 2020 to January 23rd, 2020. |
T57 |
677-748 |
Sentence |
denotes |
Thus, the main task is to estimate the parameter values q,cb,r1,δIf,r2. |
T58 |
749-919 |
Sentence |
denotes |
We use the Markov Chain Monte Carlo (MCMC) method to fit the model to the data, and adopt an adaptive Metropolis-Hastings (M-H) algorithm to carry out the MCMC procedure. |
T59 |
920-1099 |
Sentence |
denotes |
The algorithm is run for 70,000 iterations with a burn-in of the first 50,000 iterations, and the Geweke convergence diagnostic method is employed to assess convergence of chains. |
T60 |
1100-1145 |
Sentence |
denotes |
The estimation results are given in Table 1 . |
T61 |
1146-1171 |
Sentence |
denotes |
Table 1 Parameter values. |
T62 |
1172-1245 |
Sentence |
denotes |
Parameter Definitions Estimated mean value Standard deviation Data source |
T63 |
1246-1296 |
Sentence |
denotes |
c0 Contact rate at the initial time 14.781 0.904 1 |
T64 |
1297-1376 |
Sentence |
denotes |
cb Minimum contact rate under the current control strategies 2.9253 0.5235 MCMC |
T65 |
1377-1441 |
Sentence |
denotes |
r1 Exponential decreasing rate of contact rate 1.3768 0.283 MCMC |
T66 |
1442-1509 |
Sentence |
denotes |
β Probability of transmission per contact 2.1011×10−8 1.1886×10−9 1 |
T67 |
1510-1580 |
Sentence |
denotes |
q Quarantined rate of exposed individuals 1.2858×10−5 3.1488×10−6 MCMC |
T68 |
1581-1651 |
Sentence |
denotes |
σ Transition rate of exposed individuals to the infected class 1/7 – 2 |
T69 |
1652-1753 |
Sentence |
denotes |
λ Rate at which the quarantined uninfected contacts were released into the wider community 1/14 – 3,4 |
T70 |
1754-1832 |
Sentence |
denotes |
ϱ Probability of having symptoms among infected individuals 0.86834 0.049227 1 |
T71 |
1833-1949 |
Sentence |
denotes |
δI0 Initial transition rate of symptomatic infected individuals to the quarantined infected class 0.13266 0.021315 1 |
T72 |
1950-2007 |
Sentence |
denotes |
1/δIf The shortest period of diagnosis 0.3654 0.1431 MCMC |
T73 |
2008-2074 |
Sentence |
denotes |
r2 Exponential decreasing rate of diagnose rate 0.3283 0.0225 MCMC |
T74 |
2075-2180 |
Sentence |
denotes |
δq Transition rate of quarantined exposed individuals to the quarantined infected class 0.1259 0.052032 1 |
T75 |
2181-2252 |
Sentence |
denotes |
γI Recovery rate of symptomatic infected individuals 0.33029 0.052135 1 |
T76 |
2253-2325 |
Sentence |
denotes |
γA Recovery rate of asymptomatic infected individuals 0.13978 0.034821 1 |
T77 |
2326-2397 |
Sentence |
denotes |
γH Recovery rate of quarantined infected individuals 0.11624 0.038725 1 |
T78 |
2398-2452 |
Sentence |
denotes |
α Disease-induced death rate 1.7826×10−5 6.8331×10−6 1 |