Search

Understanding how human mobility pattern changes during the COVID-19 is of great importance in controlling the transmission of the pandemic. This pattern seems unpredictable due to the complex social contexts, individual behaviors, and limited data. We analyze the human mobility data of over 10 million smart devices in three major cities in China from January 2020 to March 2021. We find that the human mobility across multi-waves of epidemics presents a surprisingly similar pattern in these three cities, despite their significant gaps in geographic environments and epidemic intensities. In particular, we reveal that the COVID-19 policies and statistics (i.e., confirmed cases) dominate human mobility during the pandemic. Thus, we propose a universal conditional generative adversarial network based framework to estimate human mobility, integrating COVID-19 statistics and policies via a gating fusion module. Extensive numerical experiments demonstrate that our model is generalizable for estimating human mobility dynamics accurately across three cities with multi-waves of COVID-19. Beyond, our model also allows policymakers to better evaluate the potential influences of various policies on human mobility and mitigate the unprecedented and disruptive pandemic.

Chlamydia trachomatis is the most common sexually transmitted pathogen. Due to the latency of the symptoms, Chlamydia trachomatis cannot be diagnosed and treated in the early stage, leading to the development of severe chronic disease with complications and sequelae. Outer membrane complex protein B (OmcB) is the second most abundant outer membrane protein in chlamydia. Because of its abundance and powerful immunogenicity during the infection, OmcB has a very promising prospect in the fields of the diagnosis of CT infection and the development of vaccines. This article reviews the structure and localization of OmcB, and the related mechanisms during Chlamydia trachomatis infection. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.compeleceng.2009.02.008 Byline: Xianghui Cao (a), Jiming Chen (a), Chuanhou Gao (b), Youxian Sun (a) Keywords: Wireless sensor and actuator networks; Optimal control; Estimation; Packet loss Abstract: The wireless sensor/actuator networks (WSANs) can be used for spatially distributed control systems. With smart sensors and actuators, the WSANs are able to not only sense the control system states and report measurements, but also perform control and actuation. This paper investigates WSANs on their ability of control. A centralized controller is introduced into WSANs to make up closed-loop control systems, in which control decisions are made based on global network-wide information. A model of the control and communication over WSANs is made theoretically, based on which we achieved an optimal control method. It is demonstrated by simulations that the control method proposed could stabilize the control system quickly. Author Affiliation: (a) State Key Lab. of Industrial Control Technology, Institute of Industrial Process Control, Zhejiang University, Hangzhou 310027, PR China (b) Institute of Systems Optimization Techniques, Zhejiang University, Hangzhou 310027, PR China Article History: Received 7 March 2008; Accepted 16 February 2009

In the sintering process, it is difficult to obtain the key quality variables in real time, so there is lack of real-time information to guide the production process. Furthermore, these labeled data are too few, resulting in poor performance of conventional soft sensor models. Therefore, a novel semi-supervised dynamic feature extraction framework (SS-DTFEE) based on sequence pre-training and fine-tuning is proposed in this paper. Firstly, based on the DTFEE model, the time features of the sequences are extended and extracted. Secondly, a novel weighted bidirectional LSTM unit (BiLSTM) is designed to extract the latent variables of original sequence data. Based on improved BiLSTM, an encoder-decoder model is designed as a pre-training model with unsupervised learning to obtain the hidden information in the process. Next, through model migration and fine-tuning strategy, the prediction performance of labeled datasets is improved. The proposed method is applied in the actual sintering process to estimate the FeO content, which shows a significant improvement of the prediction accuracy, compared to traditional methods. [ABSTRACT FROM AUTHOR]

In this paper, the recurrent neural networks (RNNs) with a generalized activation function class is proposed. In this proposed model, every component of the neuron's activation function belongs to a convex hull which is bounded by two odd symmetric piecewise linear functions that are convex or concave over the real space. All of the convex hulls are composed of generalized activation function classes. The novel activation function class is not only with a more flexible and more specific description of the activation functions than other function classes but it also generalizes some traditional activation function classes. The absolute exponential stability (AEST) of the RNN with a generalized activation function class is studied through three steps. The first step is to demonstrate the global exponential stability (GES) of the equilibrium point of original RNN with a generalized activation function being equivalent to that of RNN under all vertex functions of convex hull. The second step transforms the RNN under every vertex activation function into neural networks under an array of saturated linear activation functions. Because the GES of the equilibrium point of three systems are equivalent, the next stability analysis focuses on the GES of the equilibrium point of RNN system under an array of saturated linear activation functions. The last step is to study both the existence of equilibrium point and the GES of the RNN under saturated linear activation functions using the theory of M-matrix. In the end, a two-neuron RNN with a generalized activation function is constructed to show the effectiveness of our results. Index Terms--Absolute exponential stability (AEST), convex hull, generalized activation function class, piecewise linear function, recurrent neural networks (RNNs).

The strong [[gamma].sub.[kappa]]-[[gamma].sub.cl][H.sub.[infinity]] stabilization problem is addressed in this paper. Based on the bounded real lemma, an improved sufficient condition on strong [H.sub.[infinity]] stabilization as well as its dual form is derived, which extends the ARE constraint in the former results into an inequality constraint. Two path-following algorithms are proposed to solve the associated optimization problems with BMI constraints, which lead to full order controllers. A numerical example is presented to demonstrate the effectiveness of the result. Index Terms--Bilinear matrix inequality (BMI), [H.sub.[infinity]] control, linear matrix inequality (LMI), strong stabilization.