A Total Bounded Variation Approach to Low Visibility Estimation on Expressways

Abstract

Low visibility on expressways caused by heavy fog and haze is a main reason for traffic accidents. Real-time estimation of atmospheric visibility is an effective way to reduce traffic accident rates. With the development of computer technology, estimating atmospheric visibility via computer vision becomes a research focus. However, the estimation accuracy should be enhanced since fog and haze are complex and time-varying. In this paper, a total bounded variation (TBV) approach to estimate low visibility (less than 300 m) is introduced. Surveillance images of fog and haze are processed as blurred images (pseudo-blurred images), while the surveillance images at selected road points on sunny days are handled as clear images, when considering fog and haze as noise superimposed on the clear images. By combining image spectrum and TBV, the features of foggy and hazy images can be extracted. The extraction results are compared with features of images on sunny days. Firstly, the low visibility surveillance images can be filtered out according to spectrum features of foggy and hazy images. For foggy and hazy images with visibility less than 300 m, the high-frequency coefficient ratio of Fourier (discrete cosine) transform is less than 20%, while the low-frequency coefficient ratio is between 100% and 120%. Secondly, the relationship between TBV and real visibility is established based on machine learning and piecewise stationary time series analysis. The established piecewise function can be used for visibility estimation. Finally, the visibility estimation approach proposed is validated based on real surveillance video data. The validation results are compared with the results of image contrast model. Besides, the big video data are collected from the Tongqi expressway, Jiangsu, China. A total of 1,782,000 frames were used and the relative errors of the approach proposed are less than 10%.

Pinostrobin Inhibits Proprotein Convertase Subtilisin/Kexin-type 9 (PCSK9) Gene Expression through the Modulation of FoxO3a Protein in HepG2 Cells

“…To improve the bioavailability and biological activities of pinostrobin in vivo, novel formulation or modification such as forming inclusion complexes with β-cyclodextrin may enhance its solubility in vivo and reach the concentration employed in this study. 40 Humans with nonsense or missense mutations in PCSK9, causing loss-of-function variants of PCSK9, have significantly lower levels of plasma LDL-C than normal and are protected from atherosclerotic cardiovascular diseases. 41 The inhibition of PCSK9 production or the interruption of the interaction between PCSK9 and LDLR have been successfully used to develop PCSK9 inhibitors to reduce the circulating LDL-C concentration and cardiovascular disease risk.…”

Study of the dermal anti-inflammatory, antioxidant, and analgesic activity of pinostrobin

“…The complexation process generated some changes in the anti-inflammatory activity, which may be linked to a better bioavailability of the pinostrobin molecule [ 33 , 34 ]. The anti-inflammatory activity of pinostrobin might be explained by a synergistic process in which flavonoids intervene in different active sites, producing an anti-inflammatory and analgesic response, among which we can mention the following, the inhibition of pinostrobin on COX-2 and COX-1 and the role of antioxidants in the anti-inflammatory process activity it exhibits [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. When an inflammatory process is triggered, a broad immune response is generated by a wide variety of cells such as lymphocytes, neutrophils, macrophages, leukocytes, and macrophages, which release a significant number of inflammatory cytokines such as tumor necrosis factor (TNF-α) and interleukins such as IL-1, IL-6, IL-8, IL-12, and interferon (IFN-γ).…”

“…The anti-inflammatory effect observed in this study may also explain the traditional medicinal use of the plant Renealmia alpinia , (Rottb.) Maas, by the Emberá Katíos indigenous community for snakebite treatment, since in previous studies, it has been found that methanol and dichloromethane extracts of this plant contain pinostrobin as its primary component [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ].…”

Using High-Frequency Information and RH to Estimate AQI Based on SVR

“…Visibility is measured by trained professionals in the traditional way [12]. In recent years, various techniques for estimating visibility via images were developed [13,14]. The features, such as transmittance [15], entropy [16], contrast [17], and high-frequency information [18], are extracted from images and used to estimate visibility.…”