VEHICLE TRACKING AND SPEED ESTIMATION UNDER MIXED TRAFFIC CONDITIONS USING YOLOV4 AND SORT: A CASE STUDY OF HANOI

This paper presents a method to estimate vehicle speed automatically, including cars and motorcycles under mixed traffic conditions from video sequences acquired with stationary cameras in Hanoi City of Vietnam. The motion of the vehicle is detected and tracked along the frames of the video sequences using YOLOv4 and SORT algorithms with a custom dataset. In the method, the distance traveled by the vehicle is the length of virtual point-detectors, and the travel time of the vehicle is calculated using the movement of the centroid over the entrance and exit of virtual point-detectors (i.e., region of interest), and then the speed is also estimated based on the traveled distance and the travel time. The results of two experimental studies showed that the proposed method had small values of MAPE (within 3%), proving that the proposed method is reliable and accurate for application in real-world mixed traffic environments like Hanoi, Vietnam

Modulation of chiral anomaly and bilinear magnetoconductivity in Weyl semimetals by impurity-resonance states

The phenomenon of nonlinear transport has attracted tremendous interest within the condensed matter community. We present a theoretical framework for nonlinear transport based on the nonequilibrium retarded Green's function, and examine the impact of disorder on nonlinear magnetotransport in Weyl semimetals (WSMs). It is demonstrated that bilinear magnetoconductivity can be induced in disordered WSMs by several mechanisms, including impurity-induced tilting of the Weyl cones, Lorentz-force-induced normal orbital magnetic moment, and chiral anomaly arising from the Berry-curvature-induced anomalous orbital magnetic moment. Additionally, we observe that the localization of Weyl fermions by impurity scattering will lead to resonant dips in both the chiral chemical potential and magnetoconductivity when the Fermi energy approaches the impurity resonance states. Our findings offer a theoretical proposition for modulating nonreciprocal transport in topological semimetals.Comment: 5 figure

Inverse correlation between vitamin D and C-reactive protein in newborns

Some studies suggested that adequate vitamin D might reduce inflammation in adults. However, little is known about this association in early life. We aimed to determine the relationship between cord blood 25-hydroxyvitamin D (25(OH)D) and C-reactive protein (CRP) in neonates. Cord blood levels of 25(OH)D and CRP were measured in 1491 neonates in Hefei, China. Potential confounders including maternal sociodemographic characteristics, perinatal health status, lifestyle, and birth outcomes were prospectively collected. The average values of cord blood 25(OH)D and CRP were 39.43 nmol/L (SD = 20.35) and 6.71 mg/L (SD = 3.07), respectively. Stratified by 25(OH)D levels, per 10 nmol/L increase in 25(OH)D, CRP decreased by 1.42 mg/L (95% CI: 0.90, 1.95) among neonates with 25(OH)D <25.0 nmol/L, and decreased by 0.49 mg/L (95% CI: 0.17, 0.80) among neonates with 25(OH)D between 25.0 nmol/L and 49.9 nmol/L, after adjusting for potential confounders. However, no significant association between 25(OH)D and CRP was observed among neonates with 25(OH)D ≥50 nmol/L. Cord blood 25(OH)D and CRP levels showed a significant seasonal trend with lower 25(OH)D and higher CRP during winter-spring than summer-autumn. Stratified by season, a significant linear association of 25(OH)D with CRP was observed in neonates born in winter-spring (adjusted β = −0.11, 95% CI: −0.13, −0.10), but not summer-autumn. Among neonates born in winter-spring, neonates with 25(OH)D <25 nmol/L had higher risk of CRP ≥10 mg/L (adjusted OR = 3.06, 95% CI: 2.00, 4.69), compared to neonates with 25(OH)D ≥25 nmol/L. Neonates with vitamin D deficiency had higher risk of exposure to elevated inflammation at birth

Cord blood 25-hydroxyvitamin D and fetal growth in the China-Anhui Birth Cohort Study

We determined the association of cord blood 25-hydroxyvitamin D [25(OH)D] with birth weight and the risk of small for gestational age (SGA). As part of the China-Anhui Birth Cohort (C-ABC) study, we measured cord blood levels of 25(OH)D in 1491 neonates in Hefei, China. The data on maternal sociodemographic characteristics, health status, lifestyle, birth outcomes were prospectively collected. Multiple regression models were used to estimate the association of 25(OH)D levels with birth weight and the risk of SGA. Compared with neonates in the lowest decile of cord blood 25(OH)D levels, neonates in four deciles (the fourth, fifth, sixth and seventh deciles) had significantly increased birth weight and decreased risk of SGA. Multiple linear regression models showed that per 10 nmol/L increase in cord blood 25(OH)D, birth weight increased by 61.0 g (95% CI: 31.9, 89.9) at concentrations less than 40 nmol/L, and then decreased by 68.5 g (95% CI: −110.5, −26.6) at concentrations from 40 to 70 nmol/L. This study provides the first epidemiological evidence that there was an inverted U shaped relationship between neonatal vitamin D status and fetal growth, and the risk of SGA reduced at moderate concentration

Hierarchical porous photosensitizers with efficient photooxidation

Abstract Photosensitizers (PSs) with nano- or micro-sized pore provide a great promise in the conversion of light energy into chemical fuel due to the excellent promotion for transporting singlet oxygen (1O2) into active sites. Despite such hollow PSs can be achieved by introducing molecular-level PSs into porous skeleton, however, the catalytic efficiency is far away from imagination because of the problems with pore deformation and blocking. Here, very ordered porous PSs with excellent 1O2 generation are presented from cross-linking of hierarchical porous laminates originated by co-assembly of hydrogen donative PSs and functionalized acceptor. The catalytic performance strongly depends on the preformed porous architectures, which is regulated by special recognition of hydrogen binding. As the increasing of hydrogen acceptor quantities, 2D-organized PSs laminates gradually transform into uniformly perforated porous layers with highly dispersed molecular PSs. The premature termination by porous assembly endows superior activity as well as specific selectivity for the photo-oxidative degradation, which contributes to efficient purification in aryl-bromination without any postprocessing

Stabilizing a high-voltage LiNi0.5Mn1.5O4 cathode towards all solid state batteries: a Li–Al–Ti–P–O solid electrolyte nano-shell with a host material

LiNi0.5Mn1.5O4 (LNMO) spinel has drawn increasing attention due to its high voltage, stabilized electrochemical performance and safety features as a cathode for lithium-ion batteries. However, the main challenge lies in its unstable surface structure, especially at elevated temperatures. In this paper, we decorate the LNMO precursor with a solid electrolyte of Li1.4Al0.4Ti1.6(PO4)3 (LATP) via a facile sol–gel method, followed by a co-crystallization process at 820 °C, to successfully generate a LATP modification shell at the surface of LNMO. The LATP modification shell could not only optimize the morphology of LNMO including the limitation of particle growth and control of crystalline orientation, but also realize ion doping during the co-crystallization process. By tuning the LATP contents, the 2 wt% LATP modification is found to be the most effective at balancing the interfacial stability and Li+ diffusion kinetics of LNMO, as well as enhancing its rate capability and capacity retention at high temperatures. As a result, the 2 wt% LATP-modified LNMO cathode exhibits a high reversible capacity of 84.8 mA h g−1 after 500 cycles with a capacity retention of 68.9%, and a superior rate capability (102.0 mA h g−1 at 20 C) at room temperature. Moreover, this electrode also delivers a good capacity retention of 85.7% after 100 cycles at 55 °C, which is ascribed to the stabilized interface with a LATP protective layer