http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Salje, Henrik,Cauchemez, Simon,Alera, Maria Theresa,Rodriguez-Barraquer, Isabel,Thaisomboonsuk, Butsaya,Srikiatkhachorn, Anon,Lago, Catherine B.,Villa, Daisy,Klungthong, Chonticha,Tac-An, Ilya A.,Fern Oxford University Press 2016 The Journal of Infectious Diseases Vol.213 No.4
<P>Proper understanding of the long-term epidemiology of chikungunya has been hampered by poor surveillance. Outbreak years are unpredictable and cases often misdiagnosed. Here we analyzed age-specific data from 2 serological studies (from 1973 and 2012) in Cebu, Philippines, to reconstruct both the annual probability of infection and population-level immunity over a 60-year period (1952–2012). We also explored whether seroconversions during 2012–2013 were spatially clustered. Our models identified 4 discrete outbreaks separated by an average delay of 17 years. On average, 23% (95% confidence interval [CI], 16%–37%) of the susceptible population was infected per outbreak, with >50% of the entire population remaining susceptible at any point. Participants who seroconverted during 2012–2013 were clustered at distances of <230 m, suggesting focal transmission. Large-scale outbreaks of chikungunya did not result in sustained multiyear transmission. Nevertheless, we estimate that >350 000 infections were missed by surveillance systems. Serological studies could supplement surveillance to provide important insights on pathogen circulation.</P>
Exploring the effects of speed and scale on a ship’s form factor using CFD
Terziev Momchil,Tezdogan Tahsin,Demirel Yigit Kemal,Villa Diego,Mizzi Simon,Incecik Atilla 대한조선학회 2021 International Journal of Naval Architecture and Oc Vol.13 No.1
The problem of predicting a ship’s form factor and associated scale effects has been subject to many investigations in recent years. In this study, an attempt is made to investigate whether the form factor is influenced by a change in the ship’s speed by numerically modelling a geosim series of the KCS hull form by means of a RANS solver. The turbulence dependence of the problem is also studied by altering the closure model among three widely used approaches (the k-ω, k-ω SST, and k-ε models). The results show that at very low speeds (Froude numbers in the range of 0.02–0.06) the numerical model predicts changes in the form factor of a ship between 10% and 20%, depending on the turbulence model and scale factor choices. As the speed is increased further, the form factor exhibits little change, usually in the range of 1% or less. Simulations where the Reynolds number is changed by approximately two orders of magnitude, achieved by altering the value of viscosity, confirmed that the form factor can be considered Froude-dependent only for low speeds, predicting essentially identical values when high speed cases are considered.