Design of exponential state estimators for neural networks with mixed time delays

In this Letter, the state estimation problem is dealt with for a class of recurrent neural networks (RNNs) with mixed discrete and distributed delays. The activation functions are assumed to be neither monotonic, nor differentiable, nor bounded. We aim at designing a state estimator to estimate the neuron states, through available output measurements, such that the dynamics of the estimation error is globally exponentially stable in the presence of mixed time delays. By using the Laypunov–Krasovskii functional, a linear matrix inequality (LMI) approach is developed to establish sufficient conditions to guarantee the existence of the state estimators. We show that both the existence conditions and the explicit expression of the desired estimator can be characterized in terms of the solution to an LMI. A simulation example is exploited to show the usefulness of the derived LMI-based stability conditions.     

UWB LOS/NLOS identification in multiple indoor environments using deep learning methods

Indoor location-aware service is booming in daily life and business activities, making the demand for precise indoor positioning systems thrive. The identification between line-of-sight (LOS) and non-line-of-sight (NLOS) is critical for wireless indoor time-of-arrival-based localization methods. Ultra-Wide-Band (UWB) is considered low cost among the many wireless positioning systems. It can resolve multi-path and have high penetration ability. This contribution addresses UWB NLOS/LOS identification problem in multiple environments. We propose a LOS/NLOS identification method using Convolutional Neural Network parallel with Gate Recurrent Unit, named Indoor NLOS/LOS identification Neural Network. The Convolutional Neural Network extracts spatial features of UWB channel impulse response data. While the Gate Recurrent Unit is an effective approach for designing deep recurrent neural networks which can extract temporal features. By integrating squeeze-and-extraction blocks into these architectures we can assign weights on channel-wise features. We simulated UWB channel impulse response signals in residential, office, and industrial scenarios based on the IEEE 802.15.4a channel model report. The presented network was tested in simulation scenarios and an open-source real-time measured dataset. Our method can solve NLOS identification problems for multiple indoor environments. Thus more versatile compare with networks only working in one scenario. Popular machine learning methods and deep learning methods are compared against our method. The test results show that the proposed network outperforms benchmark methods in simulation datasets and real-time measured datasets.     

Deviation Matrix,Laurent Series and Blackwell Optimality in Countable State Markov Decision Processes

This paper presents a recurrent condition on Markov decision processes with a countable state space and bounded rewards. The condition is sufficient for the existence of a Blackwell optimal stationary policy, having the Laurent series expansion with continuous coefficients. It is so relaxed that the Markov chain corresponding to a stationary policy may have countably many periodic recurrent classes. Our method finds the deviation matrix in an explicit form.     

Newton functions generating symmetric fields and irreducibility of Schur polynomials

We prove (Theorem 1.1) that if e₀>>e_r>0 are coprime integers, then the Newton functions , i=0,…,r, generate over the field of symmetric rational functions in X₁,…,X_r. This generalizes a previous result of us for r=2. This extension requires new methods, including: (i) a study of irreducibility and Galois-theoretic properties of Schur polynomials (Theorem 3.1), and (ii) the study of the dimension of the varieties obtained by intersecting Fermat hypersurfaces (Theorem 4.1). We shall also observe how these results have implications to the study of zeros of linear recurrences over function fields; in particular, we give (Theorem 4.2) a complete classification of the zeros of recurrences of order four with constant coefficients over a function field of dimension 1.     

Barnsley-Elton-Hardin的一个定理的修正

Ｂａｒｎｓｌｅｙ等在关联矩阵不可约的条件下,得到了递归ＦＩＦ的分形维数公式。本文首先指出该九公式是错误的,然后给出新的维数公式,并且新维数公式没有关联矩阵为不可约的限制条件。     

In Situ Sprayed Difunctional Gel Avoiding Microenvironments Limitations to Treat Pressure Ulcers

How to avoid the microenvironment limitations in the therapeutic process of pressure ulcers is still challenging. The development of a functional gel can kill bacteria and scavenge reactive oxygen species (ROS), which is urgently required in the therapeutic process of pressure ulcers. Herein, an in situ sprayed gel is developed with silver nanoparticles (AgNPs) and polydopamine (PDA) NPs (APG) to obviate microenvironment restrictions in treating pressure ulcers. The gel is constructed by spraying sodium alginate solution and CaCl₂ solution. AgNPs serve as an antibacterial agent in the formed gel, which can effectively cause bacterial inactivation and show more than 5 log (>99.999%) bacterial killing efficiency against methicillin-resistant S. aureus (MRSA), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli) in vitro. Meanwhile, PDA NPs serve as the antioxidative agent in the formed gel, which can facilitate the elimination of ROS to address the high ROS problem in wound microenvironment. Based on these features, it is demonstrated through cell and animal experiments that the AgNPs and PDA NPs incorporated gel can realize the effective treatment of MRSA-infected and hydrogen peroxide (H₂O₂)-sensitized pressure ulcers. It is believed that the designed system by a simple spray-coating approach can provide a new therapeutic strategy in biomedical areas.