ObjectiveCases with coronavirus disease 2019 (COVID-19) emigrated from Wuhan escalated the risk of spreading in other cities. This report focused on the outside-Wuhan patients to assess the transmission and clinical characteristics of this illness. MethodsContact investigation was conducted on each patient who admitted to the assigned hospitals in Hunan Province (geographically adjacent to Wuhan) from Jan 22, 2020 to Feb 23, 2020. Patients were confirmed by PCR test. Demographic, clinical and outcomes were collected and analyzed. ResultsOf the 104 patients, 48 (46.15%) were imported cases who were immigrated from Wuhan; 93 (89.42%) had a definite contact history with infections. Family clusters were the major body of patients. Transmission along the chain of 3 "generations" was This article is protected by copyright. All rights reserved. Accepted Articleobserved. Five asymptomatic infections were found and 2 of them infected their relatives.Mean age was 43 (rang, 8-84) years and 49 (47.12%) were male. The median incubation period was 6 (rang, 1-32) days, of 8 patients ranged from 18 to 32 days, 96 (92.31%) discharged and 1 (0.96%) died. Average hospital stay was 10 (rang, 8-14) days. ConclusionsFamily but not community transmission occupied the main body of infections in the two centers, suggesting the timely control measures after the Wuhan shutdown wok well.Asymptomatic transmission demonstrated here warned us that it may bring more risk to the spread of COVID-19. A 14-day quarantine may need to be prolonged.

Maximin distance Latin hypercube designs are commonly used for computer experiments, but the construction of such designs is challenging. We construct a series of maximin Latin hypercube designs via Williams transformations of good lattice point designs. Some constructed designs are optimal under the maximin L 1 -distance criterion, while others are asymptotically optimal. Moreover, these designs are also shown to have small pairwise correlations between columns.

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Maximin distance designs as an important class of space-filling designs are widely used in computer experiments, yet their constructions are challenging.We develop an efficient procedure to generate maximin Latin hypercube designs, as well as maximin multi-level fractional factorial designs, from existing orthogonal or nearly orthogonal arrays via level permutation and expansion. We show that the distance distributions of the generated designs are closely connected with the distance distributions and generalized word-length patterns of the initial designs. Examples are presented to show that our method outperforms many current prevailing methods.

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