57 research outputs found

    Unsupervised Domain Adaptation for COVID-19 Information Service with Contrastive Adversarial Domain Mixup

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    In the real-world application of COVID-19 misinformation detection, a fundamental challenge is the lack of the labeled COVID data to enable supervised end-to-end training of the models, especially at the early stage of the pandemic. To address this challenge, we propose an unsupervised domain adaptation framework using contrastive learning and adversarial domain mixup to transfer the knowledge from an existing source data domain to the target COVID-19 data domain. In particular, to bridge the gap between the source domain and the target domain, our method reduces a radial basis function (RBF) based discrepancy between these two domains. Moreover, we leverage the power of domain adversarial examples to establish an intermediate domain mixup, where the latent representations of the input text from both domains could be mixed during the training process. Extensive experiments on multiple real-world datasets suggest that our method can effectively adapt misinformation detection systems to the unseen COVID-19 target domain with significant improvements compared to the state-of-the-art baselines

    Impact of meteorological factors on the COVID-19 transmission: A multicity study in China

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    The purpose of the present study is to explore the associations between novel coronavirus disease 2019 (COVID- 19) case counts and meteorological factors in 30 provincial capital cities of China. We compiled a daily dataset including confirmed case counts, ambient temperature (AT), diurnal temperature range (DTR), absolute humidity (AH) and migration scale index (MSI) for each city during the period of January 20th to March 2nd, 2020. First, we explored the associations between COVID-19 confirmed case counts, meteorological factors, and MSI using non-linear regression. Then, we conducted a two-stage analysis for 17 cities with more than 50 confirmed cases. In the first stage, generalized linear models with negative binomial distribution were fitted to estimate city-specific effects of meteorological factors on confirmed case counts. In the second stage, the meta-analysis was conducted to estimate the pooled effects. Our results showed that among 13 cities that have less than 50 confirmed cases, 9 cities locate in the Northern China with average AT below0 °C, 12 cities had average AHbelow4 g/m3, and one city (Haikou) had the highest AH (14.05 g/m3). Those 17 cities with 50 and more cases accounted for 90.6% of all cases in our study. Each 1 °C increase in AT and DTR was related to the decline of daily confirmed case counts, and the corresponding pooled RRs were 0.80 (95% CI: 0.75, 0.85) and 0.90 (95% CI: 0.86, 0.95), respectively. For AH, the association with COVID-19 case counts were statistically significant in lag 07 and lag 014. In addition,we found the all these associations increased with accumulated time duration up to 14 days. In conclusions, meteorological factors play an independent role in the COVID-19 transmission after controlling population migration. Local weather condition with low temperature, mild diurnal temperature range and low humidity likely favor the transmission

    Discrepancies in resistant starch and starch physicochemical properties between rice mutants similar in high amylose content

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    The content of resistant starch (RS) was considered positively correlated with the apparent amylose content (AAC). Here, we analyzed two Indica rice mutants, RS111 and Zhedagaozhi 1B, similar in high AAC and found that their RS content differed remarkably. RS111 had higher RS3 content but lower RS2 content than Zhedagaozhi 1B; correspondingly, cooked RS111 showed slower digestibility. RS111 had smaller irregular and oval starch granules when compared with Zhedagaozhi 1B and the wild type. Zhedagaozhi 1B showed a B-type starch pattern, different from RS111 and the wild type, which showed A-type starch. Meantime, RS111 had more fa and fb1 but less fb3 than Zhedagaozhi 1B. Both mutants showed decreased viscosity and swelling power when compared with the parents. RS111 had the lowest viscosity, and Zhedagaozhi 1B had the smallest swelling power. The different fine structures of amylopectin between RS111 and Zhedagaozhi 1B led to different starch types, gelatinization properties, paste viscosity, and digestibility. In addition to enhancing amylose content, modifications on amylopectin structure showed great potent in breeding rice with different RS2 and RS3 content, which could meet the increasing needs for various rice germplasms

    Positive Function of Social Conflict: Decoding State–Church Interaction in China

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    Conflict between local state and churches in China has increased both in number and intensity in recent years due to the Chinese Communist Party’s (CCP) tightened regulation and control over religious affairs and religious groups. Drawing on the theoretical insight of the positive function of social conflict proposed by Coser and the empirical findings in China, this paper tries to decode the impact of China’s religious policies on state–church interaction under Xi Jinping’s rule. It finds that the overall impacts of state intensified control over religions are twofold. On the one hand, state intervention paradoxically serves as a facilitating factor to enhance religious group’s internal cohesion, reinforce their group identity and help them reflect on and change their survival and development strategies. On the other hand, increased state control at the same time generates an unpleasant outcome that is not beneficial for a peaceful state–church interaction

    Adaptive Fractional-Order Anti-Saturation Synchronous Control for Dual-Motor Systems

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    The synchronization error of a dual-motor system will seriously affect the motion profile accuracy. To solve this problem, an adaptive fractional-order anti-saturation synchronous control method based on fractional-order frequency-domain control theory is proposed in this paper. On the one hand, the proposed method performs a compensation on the closed-loop feedback control loop to unify the frequency-domain characteristics for a dual-motor system. With the frequency-domain characteristics’ unification module, the dual-motor system will have the same response performance regarding the input signal. On the other hand, considering that the nonlinear problem of control voltage saturation will also cause the asynchronization problem of the dual-motor system, the proposed method involves an adaptive fractional-order anti-saturation module to prevent voltage saturation and eliminate the nonlinear effects. The experimental results verify that the proposed method can accurately avoid the saturation effect and effectively reduce the synchronization error of the dual-motor system, with a root-mean-square synchronization error reduction of 80.974%. Hence, the proposed method provides an effective solution for the high-precision synchronous motion of a dual-motor system
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