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Few-shot segmentation of point cloud remains a challenging task, as there is no effective way to convert local point cloud information to global representation, which hinders the generalization ability of point features. In this study, we propose a bidirectional feature globalization (BFG) approach, which leverages the similarity measurement between point features and prototype vectors to embed global perception to local point features in a bidirectional fashion. With point-to-prototype globalization (Po2PrG), BFG aggregates local point features to prototypes according to similarity weights from dense point features to sparse prototypes. With prototype-to-point globalization (Pr2PoG), the global perception is embedded to local point features based on similarity weights from sparse prototypes to dense point features. The sparse prototypes of each class embedded with global perception are summarized to a single prototype for few-shot 3D segmentation based on the metric learning framework. Extensive experiments on S3DIS and ScanNet demonstrate that BFG significantly outperforms the state-of-the-art methods., Comment: 3DV2022 Oral

Semantic segmentation of point clouds generates comprehensive understanding of scenes through densely predicting the category for each point. Due to the unicity of receptive field, semantic segmentation of point clouds remains challenging for the expression of multi-receptive field features, which brings about the misclassification of instances with similar spatial structures. In this paper, we propose a graph convolutional network DGFA-Net rooted in dilated graph feature aggregation (DGFA), guided by multi-basis aggregation loss (MALoss) calculated through Pyramid Decoders. To configure multi-receptive field features, DGFA which takes the proposed dilated graph convolution (DGConv) as its basic building block, is designed to aggregate multi-scale feature representation by capturing dilated graphs with various receptive regions. By simultaneously considering penalizing the receptive field information with point sets of different resolutions as calculation bases, we introduce Pyramid Decoders driven by MALoss for the diversity of receptive field bases. Combining these two aspects, DGFA-Net significantly improves the segmentation performance of instances with similar spatial structures. Experiments on S3DIS, ShapeNetPart and Toronto-3D show that DGFA-Net outperforms the baseline approach, achieving a new state-of-the-art segmentation performance., AAAI Workshop 2022

Few-shot object detection, expecting detectors to detect novel classes with a few instances, has made conspicuous progress. However, the prototypes extracted by existing meta-learning based methods still suffer from insufficient representative information and lack awareness of query images, which cannot be adaptively tailored to different query images. Firstly, only the support images are involved for extracting prototypes, resulting in scarce perceptual information of query images. Secondly, all pixels of all support images are treated equally when aggregating features into prototype vectors, thus the salient objects are overwhelmed by the cluttered background. In this paper, we propose an Information-Coupled Prototype Elaboration (ICPE) method to generate specific and representative prototypes for each query image. Concretely, a conditional information coupling module is introduced to couple information from the query branch to the support branch, strengthening the query-perceptual information in support features. Besides, we design a prototype dynamic aggregation module that dynamically adjusts intra-image and inter-image aggregation weights to highlight the salient information useful for detecting query images. Experimental results on both Pascal VOC and MS COCO demonstrate that our method achieves state-of-the-art performance in almost all settings., Comment: Accepted by AAAI2023

We propose a robust adaptive Model Predictive Control (MPC) strategy with online set-based estimation for constrained linear systems with unknown parameters and bounded disturbances. A sample-based test applied to predicted trajectories is used to ensure convergence of parameter estimates by enforcing a persistence of excitation condition on the closed loop system. The control law robustly satisfies constraints and has guarantees of feasibility and input-to-state stability. Convergence of parameter set estimates to the actual system parameter vector is guaranteed under conditions on reachability and tightness of disturbance bounds.

This paper developed a novel control approach for the sparse and safe frequency regulation for inverter intensive microgrids (MGs). In the scenario, the inverters and external grids are expected to reach a synchronized desired frequency under regulations. To this end, the active power set-point acting as a control from a high-level controller is designed while considering two important performance metrics "sparsity" and "safety", which are to reduce the information exchange between controllers and ensure that the frequency keeps in safety regions during the whole operation process. Our proposed control design framework allows the sparse linear feedback controller (SLFC) to be unified with a family of conditions for safe control using control barrier functions. A quadratic programming (QP) problem is then constructed, and the real-time control policy is obtained by solving the QP problem. Importantly, we also found that the real-time control for each inverter depends on the cross-layer communication network topology which is the union of the one between controllers from SLFC and the one determined by the power flow network. Furthermore, our approach has been validated through extensive numerical simulations.

Introduction: Campylobacteriosis is an enteric bacterial zoonotic infection caused by members of the Campylobacter genus (Kirkpatrick and Tribble, 2011). C. jejuni (> 85%) and C. coli (5–10%) are the most common species associated with the disease (Patrick et al., 2018). Ingestion of as few as 500 bacteria can cause campylobacteriosis (Robinson, 1981). Although Campylobacter typically causes self-limiting human gastroenteritis, it can lead to prolonged post-infectious complications, such as Guillain-Barré syndrome, reactive arthritis, and/or post infectious-irritable bowel syndrome (Rees et al., 1995). The treatment of campylobacteriosis poses significant economic burdens worldwide, resulting in $1.56 billion in healthcare costs in the USA, $80 million in Canada, and €2.4 billion in the European Union per year (Devleesschauwer et al., 2017). The high prevalence of Campylobacter in the agri-food system is likely a major contributing factor to the incidence of campylobacteriosis. Due to its microaerobic nature, Campylobacter can colonize the intestinal tract of food-producing animals such as poultry, cattle, sheep, and swine (Hansson et al., 2018). However, it can also survive under aerobic conditions and infect humans through the food supply chain by forming biofilms or entering the viable but non-culturable state (Lv et al., 2019; Ma et al., 2022). The main route of infection has been identified as the consumption of contaminated food commodities, such as unpasteurized dairy products, undercooked poultry meat and/or contaminated water (Silva et al., 2011). Therefore, detection, characterization, and reduction of Campylobacter in the agroecosystem are of great importance. This mini-review provides an overview of the current trends in understanding Campylobacter and its interaction with the agroecosystem. We first introduce the improved methods to detect Campylobacter in various agri-food settings. Then, the prevalence of this microbe in the agri-food system as well as its characteristics are summarized. Finally, novel control strategies of Campylobacter are summarized and discussed.

Background: At present, Liver Cirrhosis (LC) is common in most later liver and gallbladder diseases that its morbidity and mortality seriously affect human health. The limitation and effectiveness of western medicine on LC have become a huge clinical challenge. However, a large number of clinical studies have shown that Yi-guan decoction has become a complementary treatment for LC. Therefore, this systematic review will aim to explore the safety and feasibility of Yi-guan decoction in the treatment of LC. Methods: We will conduct a comprehensive literature search in Medline, PubMed, Cochrane Database of Systematic Reviews, Embase, Chinese Biomedical Literatures Database, China National Knowledge Infrastructure, Wang Fang Database, Chinese Scientific Journal Database from inception to December 2020 without any language restriction, In addition, relevant literature will be searched manually. The main subject terms searched: “Yi-guan decoction” “cirrhosis” “LC”. Data entry will be performed by 2 researchers separately. Primary outcomes will be concluded: Liver function indicators: Total bilirubin, Alanine transaminase, Aspartate aminotransferase, etc. Secondary outcome indicators: Total effective rate, Nutrition index, Survival analysis, Adverse events; All randomized controlled trials collected in this study will be evaluated and rated using the Cochrane risk-of-biasassessment tool. Meta-analysis will be performed using RevMan 5.4.0 software. The heterogeneity test will be conducted between the studies, P 50% are the thresholds for the tests. Using solid effect model or random effect model will be based on its heterogeneity value. Results: This systematic review provides a theoretical basis for Yi-guan decoction to treat LC, we will report this result soon. Conclusion: This study will explore Yi-guan decoction can will be used as one of the non drug therapies to prevent or treat LC. Trial registration number: INPLASY2020120114.

International audience; Since the last two decades, microgrid, as one typical structure in smart grid framework, has been receiving increasing attention in the world. Meanwhile, fuel cell (FC), as one promising power source, has redrawn the attention of both academia and industry since the beginning of 21th century. Some encouraging achievements in FC technology have been realized thanks to the efforts taken in the last years. Due to this, it is seen that FC, as a clean and efficient energy source, is penetrating into different fields. Among the applications, integrating FCs into microgrids has shown interesting advantages on improving the performance of microgrids and promoting the use of the hydrogen energy. Some ongoing projects have shown that FCs of different power scales can be integrated into microgrids smartly and in different manners. Along with the advantages carried by the combination of the two technologies, many challenges lying on multiple domains are faced in the process. The challenges can be from the FC, the microgrid, and the integration of these two technologies. In this review paper, the advantages of integrating FCs into microgrids are summarized after recalling the knowledge background of FC. The challenges and ongoing researches on FCs and FCs based microgrids are then reviewed. Based on the analysis, the research directions are then extracted in view of the challenges.

This paper performs an extensive review on control schemes and architectures applied to DC microgrids. It covers multi-layer hierarchical control schemes, coordinated control strategies, plug-and-play operations, stability and active damping aspects as well as nonlinear control algorithms. Islanding detection, protection and microgrid clusters control are also briefly summarized. All the mentioned issues are discussed with the goal of providing control design guidelines for DC microgrids. The future research challenges, from the authors’ point of view, are also provided in the final concluding part.

A field experiment with five lime rates (0, 3.75, 7.50, 11.25, and 15.00 Mg ha−1) was maintained on a red soil (Ultisol) for 15 years to determine changes of soil acidity and effect on crop yields. The soil acidity decreased while exchangeable Ca in plough layer (0–20 cm) increased with lime rate and time. The decreased subsoil (20–60 cm) acidity started to occur four years after liming, and the extent of decreased soil acidity increased with lime rate and time. The increased ranges of exchangeable Mg2+ in subsoil were greater than that of exchangeable Ca2+, suggesting that downward movement of Mg2+ into the subsoil was faster than that of Ca2+. Lime application significantly increased the yields of crops studied. During the period of experiment, the maximum yield increased 4.67 times for barley, 2.24 times for mungbean, 57.3% for wheat, 53.4% for sesame, 52.8% for broad bean, 44.1% for potato, 35.1% for rapeseed, 32.1% for cotton, 28.4% for corn, 18.5% for watermelon, 11.0% for cowpea and 8.8 % for soybean. Liming at the highest rate was in favor to the decline in subsoil acidity and yield increase, especially for the later period of the experiment. Residual effects of reducing soil acidity by liming for the treatments of 0.5 L, 1.0 L, 1.5 L, and 2.0 L could last for 5, 7, 12, and 14 years, respectively, and the effects of lime application on the yields could last for more than 15 years.

In order to enhance the DC side performance of AC-DC hybrid microgrid,a DC hierarchical control system is proposed in this paper.To meet the requirement of DC load sharing between the parallel power interfaces,droop method is adopted.Meanwhile,DC voltage secondary control is employed to restore the deviation in the DC bus voltage.The hierarchical control system is composed of two levels.DC voltage and AC current controllers are achieved in the primary control level.

In order to take advantage of the dispersed energy storage units in the DC micro-grids, an improved state of charge (SOC) based droop control method for energy storage systems was proposed in this paper. Dynamic load power sharing among different energy storage units was achieved by using this method. Specifically, the coefficient in the conventional droop control method was set to be inversely proportional to the nth order of SOC. The speed of SOC and output power equalization can be adjusted by changing the exponent n of SOC. Since the above method was realized based on droop control, the deviation in the DC bus voltage was involved. Secondary control method was employed in this paper in order to restore the bus voltage to its reference value. The conventional secondary control was used for the droop control method with constant droop coefficient. In the above improved droop control method, the droop coefficient was changed by the SOC. It acted upon secondary control as a disturbance. In this paper, the feasibility of secondary control for the SOC-based droop control method was tested. The model of the overall control system was obtained and the system stability was thereby studied based on it. Simulation validation was realized by Matlab/Simulink and a 2×2.2 kW prototype based on dSPACE1103 was implemented for the experimental demonstration. In order to take advantage of the dispersed energy storage units in the DC micro-grids, an improved state of charge (SOC) based droop control method for energy storage systems was proposed in this paper. Dynamic load power sharing among different energy storage units was achieved by using this method. Specifically, the coefficient in the conventional droop control method was set to be inversely proportional to the nth order of SOC. The speed of SOC and output power equalization can be adjusted by changing the exponent n of SOC. Since the above method was realized based on droop control, the deviation in the DC bus voltage was involved. Secondary control method was employed in this paper in order to restore the bus voltage to its reference value. The conventional secondary control was used for the droop control method with constant droop coefficient. In the above improved droop control method, the droop coefficient was changed by the SOC. It acted upon secondary control as a disturbance. In this paper, the feasibility of secondary control for the SOC-based droop control method was tested. The model of the overall control system was obtained and the system stability was thereby studied based on it. Simulation validation was realized by Matlab/Simulink and a 2×2.2 kW prototype based on dSPACE1103 was implemented for the experimental demonstration.

Fabric has emerged as an alternative to paper for the fabrication of microfluidic devices. Fabric could be easily manufactured using various natural and synthetic materials that contain a wide variety of functional groups, which can participate in binding to different types of molecules without further functionalization. To allow a rapid fabrication of more sophisticated fabric-based devices, we demonstrate that a commercial wax printer can be used to print 2D and 3D devices on fabric, followed by melting wax into fabric with heat treatment. The heating temperature and time were optimized to create the devices. The relationship between the width of the originally printed lines and the formed hydrophobic barriers was also investigated. The developed microfluidic fabric-based analytical devices show great potentials for real-life applications using colorimetric assay. Refereed/Peer-reviewed

This work demonstrates a sensitive and rapid method for the detection of antibiotic residues in food samples by employing the filtration behaviour of paper combined with aggregation and precipitation of chemical reagents. Using this concept, we successfully determined the presence of oxytetracycline and norfloxacin residues in pork using metal complexation on microfluidic paper-based analytical devices (μPADs). The base substrate (top layer of the device) was fabricated by printing letter channels of the words “oxytetracycline” and “norfloxacin” before functionalization with copper (II) sulfate pentahydrate in 0.5 M sodium hydroxide and iron (III) nitrate nanohydrate in 5 mM ammonia solution for the detection of oxytetracycline and norfloxacin separately. A transition metal hydroxide formed upon reaction that created solid precipitates on paper and allowed antibiotic residues to bind to the metal ions via coordination chemistry. The metal ion-antibiotic complex could form on the filter paper and generated a visible color change with the detection limit of 1 ppm for both oxytetracycline and norfloxacin in pork. This procedure of filtration and concentration in combination with a simple text-reporting approach allows the end users to achieve a low limit of detection as well as easy result interpretation in food safety monitoring. usc Refereed/Peer-reviewed

We demonstrate that polysiloxanes can be tuned to be partially hydrophilic for manipulating the fluidic flow in the pores of cotton thread-based microfluidic devices. A mixture of methanol and isopropanol was used as a diluent for siloxane precursor, which was included into the thread to enable rapid curing of polysiloxanes for fluidic control and enhance detection sensitivity. Interestingly, twelve-fold diluted polysiloxanes enabled desirable fluidic delay and optimum interaction between the targeted antigen and detection antibody-gold nanoparticles (dAb-AuNPs) in the thread-based immunoassay, generating more antigen-dAb-AuNP complexes that bound to the capture antibody (cAb) at the test zone and achieved signal enhancement (∼10-fold over unmodified device). The phenomenon of fluidic delay was evaluated by mathematical simulation, through which the fluidic movement on the polysiloxanes-coated region was observed and the simulation data was in agreement with the experimental data. This polysiloxanes-modified device could detect Salmonella enterica serotype Enteritidis (as a model analyte) in phosphate buffered saline, spiked whole milk, juice and lettuce with the detection limit of 500, 1000, 1000 and 5000 CFU/mL, respectively, which was comparable to or even more sensitive than the existing immunoassays. This work expands the application of polysiloxanes in the microfluidic devices for biomedical diagnosis, water quality monitoring, and food safety surveillance. usc Refereed/Peer-reviewed

In this study, a paper-based microfluidic enzyme-linked immunosorbent assay (ELISA) was developed as a screening system for rapid detection of clenbuterol, which is illegally used as a growth promoter for food-producing animals. The microfluidic paper-based analytical device (μPAD) was combined with ELISA and the intrinsic properties of paper allowed the entrapment of antibody through cellulosic fibres, validating to be an alternative to 96-well ELISA microplate for food safety monitoring. Detection of clenbuterol in milk was achieved by measuring the intensity of colour change that was proportional to the analyte concentration with a detection limit of 0.2 ppb. The μPAD effectively reduces the cost, volume of reagents, and time required to run ELISA for food sample testing. usc Refereed/Peer-reviewed

usc Cell culture systems have validated to be able to mimic living organisms for various biological applications. In the current study, we demonstrated a method of fabricating three-dimensional (3D) cell culture system by stacking multiple layers of polydimethylsiloxane (PDMS) embedded with functionalized hydroxypropyl cellulose methacrylate (HPC-MA) porous scaffolds, which were connected through thread as a readymade hydrophilic channel. Thread could wick and distribute micro volumes of liquid samples from single inlet point into arrays of detection and working zones without the requirement of either pump or external pressure. Thread with an average thickness of 300 μm provided sufficient rate to continuously supply the media into the system in less than 250 s and remove waste from the cell culture system. The number of COS-7 cells present in the multilayer culture system was comparatively identical to the cells grown in the tissue culture dish and scaffold in a microwell plate. This multilayer cell culture system can be applied to implantable biodegradable poly(lactic-co-glycolic acid) (PLGA) suture as well as initiating cell differentiation in multilayers. Refereed/Peer-reviewed

The screening of biological contaminants, chemical hazards and allergens in food products is critical to understanding the potential negative effects on human health. Intensive research has been conducted to develop various detection methods to monitor food safety and quality. However, most of these developed methods are costly and require supporting equipment and professional skills to perform the testing. Therefore, there is high demand to develop alternative and innovative methods that are affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free and deliverable to fulfil the “ASSURED” criteria set by the World Health Organization (WHO). Colorimetric analysis can identify and determine the content of chemical elements/compounds in sample solutions by using various color reagents. This method has been used to detect and quantify specific pathogens, chemicals and hazards in foods for safety and quality control, which are suitable for use in laboratories and field studies. This chapter summarizes the recent advances in colorimetric analysis for assessing food safety and quality assurance, such as colorimetric detection of pathogens, toxins, parasites, antibiotic residues and chemical hazards in agri-food products. This chapter also conveys the current technical limitations and strategic research of colorimetric analysis required to further improve the performance of analytical assays in sensing food safety and quality control.