Prototypical Residual Networks for Anomaly Detection and Localization

Anomaly detection and localization are widely used in industrial manufacturing for its efficiency and effectiveness. Anomalies are rare and hard to collect and supervised models easily over-fit to these seen anomalies with a handful of abnormal samples, producing unsatisfactory performance. On the other hand, anomalies are typically subtle, hard to discern, and of various appearance, making it difficult to detect anomalies and let alone locate anomalous regions. To address these issues, we propose a framework called Prototypical Residual Network (PRN), which learns feature residuals of varying scales and sizes between anomalous and normal patterns to accurately reconstruct the segmentation maps of anomalous regions. PRN mainly consists of two parts: multi-scale prototypes that explicitly represent the residual features of anomalies to normal patterns; a multisize self-attention mechanism that enables variable-sized anomalous feature learning. Besides, we present a variety of anomaly generation strategies that consider both seen and unseen appearance variance to enlarge and diversify anomalies. Extensive experiments on the challenging and widely used MVTec AD benchmark show that PRN outperforms current state-of-the-art unsupervised and supervised methods. We further report SOTA results on three additional datasets to demonstrate the effectiveness and generalizability of PRN.Comment: Accepted by CVPR 202

Resolving Task Confusion in Dynamic Expansion Architectures for Class Incremental Learning

The dynamic expansion architecture is becoming popular in class incremental learning, mainly due to its advantages in alleviating catastrophic forgetting. However, task confu- sion is not well assessed within this framework, e.g., the discrepancy between classes of different tasks is not well learned (i.e., inter-task confusion, ITC), and certain prior- ity is still given to the latest class batch (i.e., old-new con- fusion, ONC). We empirically validate the side effects of the two types of confusion. Meanwhile, a novel solution called Task Correlated Incremental Learning (TCIL) is pro- posed to encourage discriminative and fair feature utilization across tasks. TCIL performs a multi-level knowledge distil- lation to propagate knowledge learned from old tasks to the new one. It establishes information flow paths at both fea- ture and logit levels, enabling the learning to be aware of old classes. Besides, attention mechanism and classifier re- scoring are applied to generate more fair classification scores. We conduct extensive experiments on CIFAR100 and Ima- geNet100 datasets. The results demonstrate that TCIL con- sistently achieves state-of-the-art accuracy. It mitigates both ITC and ONC, while showing advantages in battle with catas- trophic forgetting even no rehearsal memory is reserved. Source code: https://github.com/YellowPancake/TCIL

Biodegradation of decabromodiphenyl ether (BDE 209) by a newly isolated bacterium from an e-waste recycling area

Abstract Polybrominated diphenyl ethers (PBDEs) have become widespread environmental pollutants all over the world. A newly isolated bacterium from an e-waste recycling area, Stenotrophomonas sp. strain WZN-1, can degrade decabromodiphenyl ether (BDE 209) effectively under aerobic conditions. Orthogonal test results showed that the optimum conditions for BDE 209 biodegradation were pH 5, 25 °C, 0.5% salinity, 150 mL minimal salt medium volume. Under the optimized condition, strain WZN-1 could degrade 55.15% of 65 μg/L BDE 209 under aerobic condition within 30 day incubation. Moreover, BDE 209 degradation kinetics was fitted to a first-order kinetics model. The biodegradation mechanism of BDE 209 by strain WZN-1 were supposed to be three possible metabolic pathways: debromination, hydroxylation, and ring opening processes. Four BDE 209 degradation genes, including one hydrolase, one dioxygenase and two dehalogenases, were identified based on the complete genome sequencing of strain WZN-1. The real-time qPCR demonstrated that the expression level of four identified genes were significantly induced by BDE 209, and they played an important role in the degradation process. This study is the first to demonstrate that the newly isolated Stenotrophomonas strain has an efficient BDE 209 degradation ability and would provide new insights for the microbial degradation of PBDEs

Exposure pathways, levels and toxicity of polybrominated diphenyl ethers in humans: a review

Polybrominated diphenyl ethers (PBDEs) are extensively used as brominated flame retardants (BFRs) in different types of materials, which have been listed as Persistent Organic Pollutants (POPs) by the Stockholm Convention in 2009 and 2017. Due to their ubiquities in the environment and toxicities, PBDEs have posed great threat to both human health and ecosystems. The aim of this review is to offer a comprehensive understanding of the exposure pathways, levels and trends and associated health risks of PBDEs in human body in a global scale. We systematically reviewed and described the scientific data of PBDE researches worldwide from 2010 to March 2020, focusing on the following three areas: (1) sources and human external exposure pathways of PBDEs; (2) PBDE levels and trends in humans; (3) human data of PBDEs toxicity. Dietary intake and dust ingestion are dominant human exposure pathways. PBDEs were widely detected in human samples, especially in human serum and human milk. Data showed that PBDEs are generally declining in human samples worldwide as a result of their phasing out. Due to the common use of PBDEs, their levels in humans from the USA were generally higher than that in other countries. High concentrations of PBDEs have been detected in humans from PBDE production regions and e-waste recycling sites. BDE-47, -153 and -99 were proved to be the primary congeners in humans. Human toxicity data demonstrated that PBDEs have extensively endocrine disruption effects, developmental effects, and carcinogenic effects among different populations

Plant Disease Recognition Model Based on Improved YOLOv5

To accurately recognize plant diseases under complex natural conditions, an improved plant disease-recognition model based on the original YOLOv5 network model was established. First, a new InvolutionBottleneck module was used to reduce the numbers of parameters and calculations, and to capture long-distance information in the space. Second, an SE module was added to improve the sensitivity of the model to channel features. Finally, the loss function ‘Generalized Intersection over Union’ was changed to ‘Efficient Intersection over Union’ to address the former’s degeneration into ‘Intersection over Union’. These proposed methods were used to improve the target recognition effect of the network model. In the experimental phase, to verify the effectiveness of the model, sample images were randomly selected from the constructed rubber tree disease database to form training and test sets. The test results showed that the mean average precision of the improved YOLOv5 network reached 70%, which is 5.4% higher than that of the original YOLOv5 network. The precision values of this model for powdery mildew and anthracnose detection were 86.5% and 86.8%, respectively. The overall detection performance of the improved YOLOv5 network was significantly better compared with those of the original YOLOv5 and the YOLOX_nano network models. The improved model accurately identified plant diseases under natural conditions, and it provides a technical reference for the prevention and control of plant diseases

Upgrading the peroxi-coagulation treatment of complex water matrices using a magnetically assembled mZVI/DSA anode: Insights into the importance of ClO radical

electrochemical technologies for water treatment have flourished over the last decades. However, it is still challenging to treat the actual complex water effluents by a single electrochemical process, often requiring coupling of technologies. In this study, an upgraded peroxi-coagulation (PC) process with a magnetically assembled mZVI/DSA anode has been devised for the first time. COD, NH3-N and total phosphorous were simultaneously and effectively removed from livestock wastewater. The advantages, influence of key parameters and evolution of electrogenerated species were systematically investigated to fully understand this novel PC process. The fluorescent substances in livestock wastewater could also be almost removed under optimal conditions (300 mA, 0.2 g ZVI particles and pH 6.8). The interaction between ¿OH and active chlorine yielded ClO¿ with a high steady-state concentration of 6.85 × 10 13 M, which did not cause COD removal but accelerated the oxidation of NH3-N. The Mulliken population suggested that ¿OH and NH3-N had similar electron-donor behavior, whereas ClO¿ acted as an electron-withdrawing species. Besides, although the energy barrier for the reaction between ¿OH and NH3-N (17.0 kcal/mol) was lower than that with ClO¿ (18.8 kcal/mol), considering the tunneling in the H abstraction reaction, the Skodje-Truhlar method adopted for calculations evidenced a 17-fold faster NH3-N oxidation rate with ClO¿. In summary, this work describes an advantageous single electrochemical process for the effective treatment of a complex water matrix

The Effectiveness of Exfiltration Technology to Support Sponge City Objectives

Urban stormwater management is essential to improve the management of floodwaters in municipalities in urban areas. However, relying on sponge city options for site planning in an attempt to decrease the impacts of flooding is challenging due to the magnitude of flooding in urban China. The merits of exfiltration technology being used in Canada are described as having significant potential; this technology encourages passage from the stormwater pipe down to a second, lower pipe, to facilitate exfiltration to the vadose zone and, ultimately, to replenish groundwater. For example, for a small urban catchment, stormwater runoff from a 2-h long, 5-yearly storm, is demonstrated as being able to exfiltrate approximately 53% of the stormwater. Overall, the potential exists to exfiltrate stormwater from the lower pipe and it is estimated that 71% of the water entering the storm sewer is exfiltrated to the vadose zone, for a small catchment. The exfiltration pipe technology increases groundwater recharge which provides an opportunity to help manage subsidence in China. However, attention must be paid to the quality of the infiltrating water since, as true for any sponge city initiative, poor quality infiltrating water may deteriorate the quality of the groundwater

Photochlorination-induced transformation of graphene oxide: Mechanism and environmental fate.

With the increasing production and wide utilization of graphene oxide (GO), the nanomaterials are expected to be released into the environment, and end up in surface waters, and/or wastewater treatment plants. This study explored the changes in the physicochemical properties of GO resulting from photochlorination- simulating the reactions that occur during water and wastewater treatment. Photochlorination resulted in significant changes in the surface oxygen-functionalities of the nanomaterials, and fragmenting of the graphenic carbon sheets was observed. We found that photochlorination can enhance the decomposition of GO through the formation of reduced GO. The changes in surface oxygen-functionalities of GO were attributed to the oxidation by chlorine of the nanomaterials' quinone groups, and further oxidation by and/or radicals. The surface charge of GO, measured by its zeta potential, increased in magnitude with chlorination but decreased in magnitude with photochlorination, leading to the decrease in the colloidal stability of the photochlorinated nanomaterials. The antibacterial effect of the nanomaterials increased with both chlorination and photochlorination. This study clearly shows how the physicochemical properties, and environmental fate and effect of GO are modified by photochlorination

Kinetics of V(V) extraction in V(V)-SO42- (Na+, H+)-primary amine N1923-sulfonated kerosene system using single drop technique

The kinetics of V(V) extraction from acidic sulfate medium by primary amine N1923(RNH2) dissolved in sulfonated kerosene has been investigated using a falling single drop technique. The time of drop formation and coalescence was determined and considered for calculating the V(V) transfer flux. The effects of aqueous pH, V(V) concentration and RNH2 concentration on the revised V(V)-transfer flux(F') have been investigated with aim of obtaining the reaction orders for extraction rate. Activation energies (E-a) of extracted reaction for the aqueous pH of 2.0, 3.0 and 4.0 under the conditions of V(V) concentration of 0.24 mol/L, RNH2 concentration of 0.24 mol/L, temperature of 298 +/- 0.5 K and an atmospheric pressure, were -8.04, - 9.57 and -12.45 kJ/mol, respectively. The Delta H-+/- for reactions under various operating conditions were also calculated according to the intercept of log(F'h/kT) versus (1/T)n plots. The details studies on the kinetics of V(V) extraction from simulated industrial aqueous solution are significant to optimize its separation technology

Removal Efficiency and Risk Assessment of Polycyclic Aromatic Hydrocarbons in a Typical Municipal Wastewater Treatment Facility in Guangzhou, China

The loading and removal efficiency of 16 US EPA polycyclic aromatic hydrocarbons (PAHs) were examined in an inverted A2/O wastewater treatment plant (WWTP) located in an urban area in China. The total PAH concentrations were 554.3 to 723.2 ng/L in the influent and 189.6 to 262.7 ng/L in the effluent. The removal efficiencies of ∑PAHs in the dissolved phase ranged from 63 to 69%, with the highest observed in naphthalene (80% removal). Concentration and distribution of PAHs revealed that the higher molecular weight PAHs became more concentrated with treatment in both the dissolved phase and the dewatered sludge. The sharpest reduction was observed during the pretreatment and the biological phase. Noncarcinogenic risk, carcinogenic risk, and total health risk of PAHs found in the effluent and sewage sludge were also assessed. The effluent BaP toxic equivalent quantities (TEQBaP) were above, or far above, standards in countries. The potential toxicities of PAHs in sewage effluent were approximately 10 to 15 times higher than the acceptable risk level in China. The health risk associated with the sewage sludge also exceeded international recommended levels and was mainly contributed from seven carcinogenic PAHs. Given that WWTP effluent is a major PAH contributor to surface water bodies in China and better reduction efficiencies are achievable, the present study highlights the possibility of utilizing WWTPs for restoring water quality in riverine and coastal regions heavily impacted by PAHs contamination