EKF/UKF-based channel estimation for robust and reliable communications in V2V and IIoT

Cyber-physical systems (CPSs) are characterized by integrating computation, communication, and physical system. In typical CPS application scenarios, vehicle-to-vehicle (V2V) and Industry Internet of Things (IIoT), due to doubly selective fading and non-stationary channel characteristics, the robust and reliable end-to-end communication is extremely important. Channel estimation is a major signal processing technology to ensure robust and reliable communication. However, the existing channel estimation methods for V2V and IIoT cannot effectively reduce intercarrier interference (ICI) and lower the computation complexity, thus leading to poor robustness. Aiming at this challenge, according to the channel characteristics of V2V and IIoT, we design two channel estimation methods based on the Bayesian filter to promote the robustness and reliability of end-to-end communication. For the channels with doubly selective fading and non-stationary characteristics of V2V and IIoT scenarios, in the one hand, basis extended model (BEM) is used to further reduce the complexity of the channel estimation algorithm under the premise that ICI can be eliminated in the channel estimation. On the other hand, aiming at the non-stationary channel, a channel estimation and interpolation method based on extended Kalman filter (EKF) and unscented Kalman filter (UKF) Bayesian filters to jointly estimate the channel impulse response (CIR) and time-varying time domain autocorrelation coefficient is adopted. Through the MATLAB simulation, the robustness and reliability of end-to-end communication for V2V and IIoT are promoted by the proposed algorithms

Photocatalytic Removal of Organics over BiVO4-Based Photocatalysts

Organic compounds, such as organic dyes and phenols, are the main pollutants in wastewater. In the past years, a large number of studies on the fabrication and photocatalytic organics degradation of BiVO4 and its related materials have been reported in the literature. In this chapter, we shall focus on the advancements in the synthesis and photocatalytic applications of several kinds of BiVO4-based photocatalysts: (i) well-defined morphological BiVO4 photocatalysts, (ii) porous BiVO4 photocatalysts, (iii) heteroatom-doped BiVO4 photocatalysts, (iv) BiVO4-based heterojunction photocatalysts, and (v) supported BiVO4 photocatalysts. We shall discuss the structure–photocatalytic performance relationship of the materials and the involved photocatalytic degradation mechanisms. In addition, we also propose the research trends and technologies for practical applications of the BiVO4-based photocatalytic materials

Full-space Cloud of Random Points with a Scrambling Metasurface

With the rapid progress in computer science, including artificial intelligence, big data and cloud computing, full-space spot generation can be pivotal to many practical applications, such as facial recognition, motion detection, augmented reality, etc. These opportunities may be achieved by using diffractive optical elements (DOEs) or light detection and ranging (LIDAR). However, DOEs suffer from intrinsic limitations, such as demanding depth-controlled fabrication techniques, large thicknesses (more than the wavelength), Lambertian operation only in half space, etc. LIDAR nevertheless relies on complex and bulky scanning systems, which hinders the miniaturization of the spot generator. Here, inspired by a Lambertian scatterer, we report a Hermitian-conjugate metasurface scrambling the incident light to a cloud of random points in full space with compressed information density, functioning in both transmission and reflection spaces. Over 4044 random spots are experimentally observed in the entire space, covering angles at nearly 90 degrees. Our scrambling metasurface is made of amorphous silicon with a uniform subwavelength height, a nearly continuous phase coverage, a lightweight, flexible design, and low-heat dissipation. Thus, it may be mass produced by and integrated into existing semiconductor foundry designs. Our work opens important directions for emerging 3D recognition sensors, such as motion sensing, facial recognition, and other applications.113Nsciescopu

Hβ\beta Line Widths as an Orientation Indicator for Low-Ionization Broad Absorption Line Quasars

There is evidence from radio-loud quasars to suggest that the distribution of the H$\beta$ broad emission line (BEL) gas is arranged in a predominantly planar orientation, and this result may well also apply to radio-quiet quasars. This would imply that the observed full width at half maximum (FWHM) of the H$\beta$ BELs is dependent on the orientation of the line of sight to the gas. If this view is correct then we propose that the FWHM can be used as a surrogate, in large samples, to determine the line of sight to the H$\beta$ BELs in broad absorption line quasars (BALQSOs).... It is determined that there is a statistically significant excess of narrow line profiles in the SDSS DR7 archival spectra of low ionization broad absorption line quasars (LoBALQSOs), indicating that BAL gas flowing close to the equatorial plane does not commonly occur in these sources. We also find that the data is not well represented by random lines of sight to the BAL gas. Our best fit indicates two classes of LoBALQSOs, the majority ($\approx 2/3$) are polar outflows, that are responsible for the enhanced frequency of narrow line profiles, and the remainder are equatorial outflows. We further motivated the line of sight explanation of the narrow line excess in LoBALQSOs by considering the notion that the skewed distribution of line profiles is driven by an elevated Eddington ratio in BALQSOs. We constructed a variety of control samples comprised of nonLoBALQSOs matched to a de-reddened LoBALQSO sample in redshift, luminosity, black hole mass and Eddington ratio. It is demonstrated that the excess of narrow profiles persists within the LoBALQSO sample relative to each of the control samples with no reduction of the statistical significance. Thus, we eliminate the possibility that the excess narrow lines seen in the LoBALQSOs arise from an enhanced Eddington ratio.Comment: To appear in Ap

PD-1hi CD8+ resident memory T cells balance immunity and fibrotic sequelae

CD8+ tissue-resident memory T (TRM) cells provide frontline immunity in mucosal tissues. The mechanisms regulating CD8+ TRM maintenance, heterogeneity, and protective and pathological functions are largely elusive. Here, we identify a population of CD8+ TRM cells that is maintained by major histocompatibility complex class I (MHC-I) signaling, and CD80 and CD86 costimulation after acute influenza infection. These TRM cells have both exhausted-like phenotypes and memory features and provide heterologous immunity against secondary infection. PD-L1 blockade after the resolution of primary infection promotes the rejuvenation of these exhausted-like TRM cells, restoring protective immunity at the cost of promoting postinfection inflammatory and fibrotic sequelae. Thus, PD-1 serves to limit the pathogenic capacity of exhausted-like TRM cells at the memory phase. Our data indicate that TRM cell exhaustion is the result of a tissue-specific cellular adaptation that balances fibrotic sequelae with protective immunity

Advances in genetic engineering of domestic animals

Global population will increase to over nine billion by 2050 with the doubling in demand for meat and milk. To overcome this challenge, it is necessary to breed highly efficient and productive livestock. Furthermore, livestock are also excellent models for human diseases and ideal bioreactors to produce pharmaceutical proteins. Thus, genetic engineering of domestic animals presents a critical and valuable tool to address these agricultural and biomedical applications. Overall, genetic engineering has evolved through three stages in history: transgenesis, gene targeting, and gene editing. Since the birth of the first transgenic pig, genetic engineering in livestock has been advancing slowly due to inherent technical limitations. A major breakthrough has been the advent of somatic cell nuclear transfer, which, for the first time, provided the technical ability to produce site-specific genome-modified domestic animals. However, the low efficiency of gene targeting events in somatic cells prohibits its wide use in agricultural and biomedical applications. Recently, rapid progress in tools and methods of genome engineering has been made, allowing genetic editing from mutation of a single base pair to the deletion of entire chromosomes. Here, we review the major advances of genetic engineering in domestic animals with emphasis placed on the introduction of latest designer nucleases

Thioetherimide-Modified Cyanate Ester Resin with Better Molding Performance for Glass Fiber Reinforced Composites

Cyanate ester (CE) resins with higher heat resistance, lower coefficients of thermal expansion (CTEs), and lower water absorption ratios are highly desired in printed circuit boards (PCBs). In this work, a CE was modified by copolymerization with a long-chain thioether bismaleimide (SBMI) to form a thioetherimide-modified CE (SBT). The results indicated that SBT had a wider processing window and better processing properties than a common bismaleimide-modified CE resin (MBMI). After molding with a glass fiber cloth, the composites (GSBT) exhibited moisture adsorption in the range of 1.4%–2.0%, high tensile strength in the range of 311–439 MPa, good mechanical retention of 70%–85% even at 200 °C, and good dimension stability, with coefficients of thermal expansion in the range of 17.3–18.6 (×10−6 m/°C). Such GSBT composites with superior properties would be good candidates for PCB applications