Clustering face images according to their latent identity has two important applications: 1) grouping a collection of face images when no external labels are associated with images, and 2) indexing ...for efficient large scale face retrieval. The clustering problem is composed of two key parts: representation and similarity metric for face images, and choice of the partition algorithm. We first propose a representation based on ResNet, which has been shown to perform very well in image classification problems. Given this representation, we design a clustering algorithm, Conditional Pairwise Clustering (ConPaC), which directly estimates the adjacency matrix only based on the similarities between face images. This allows a dynamic selection of number of clusters and retains pairwise similarities between faces. ConPaC formulates the clustering problem as a Conditional Random Field model and uses Loopy Belief Propagation to find an approximate solution for maximizing the posterior probability of the adjacency matrix. Experimental results on two benchmark face datasets (LFW and IJB-B) show that ConPaC outperforms well known clustering algorithms such as k-means, spectral clustering, and approximate Rank-order. Additionally, our algorithm can naturally incorporate pairwise constraints to work in a semi-supervised way that leads to improved clustering performance. We also propose a k-NN variant of ConPaC, which has a linear time complexity given a k-NN graph, suitable for large datasets.
SIPRα on macrophages binds with CD47 to resist proengulfment signals, but how the downstream signal of SIPRα controls tumor-infiltrating macrophages (TIMs) is still poorly clarified. Here, we report ...that the CD47/signal regulatory protein α (SIRPα) axis requires the deneddylation of tyrosine phosphatase SHP2. Mechanistically, Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2) was constitutively neddylated on K358 and K364 sites; thus, its autoinhibited conformation was maintained. In response to CD47-liganded SIRPα, SHP2 was deneddylated by sentrin-specific protease 8 (SENP8), which led to the dephosphorylation of relevant substrates at the phagocytic cup and subsequent inhibition of macrophage phagocytosis. Furthermore, neddylation inactivated myeloid-SHP2 and greatly boosted the efficacy of colorectal cancer (CRC) immunotherapy. Importantly, we observed that supplementation with SHP2 allosteric inhibitors sensitized immune treatment-resistant CRC to immunotherapy. Our results emphasize that the CRC subtype that is unresponsive to immunotherapy relies on SIRPαhiSHP2hiNEDD8lo TIMs and highlight the need to further explore the strategy of SHP2 targeting in CRC therapy.
Methods for detecting contaminants in drinking water are crucial for protecting public health. Despite manganese (Mn) being an essential mineral for humans, Mn in high concentrations is suspected of ...being associated with negative cognitive and neurological effects on humans, especially on children. Current methods of detection, though reliable, are limited in the application to real-time easy-to-use, field or bench-top monitoring applications for testing drinking water. Herein, chronoamperometry (CA) is explored to quantitatively analyze manganese samples for drinking water applications. CA proved to be effective at measuring the concentration of Mn
2+
in water samples with excellent recovery rates (97.8%) and reproducibility between electrodes. With 1-min deposition using bare gold electrodes, CA was able to obtain a detection limit of 34.3 µM. Furthermore, with a 5-min deposition using bare gold electrodes, CA was able to obtain a detection limit of 4.64 µM. This new CA method also offers a simplified cleaning method that will allow electrodes to be used continuously for differing samples or replicate tests. The cleaning procedure permits the reuse of electrodes, while simultaneously eliminating the need for special surface modifications on the electrodes. Ultimately, this cleaning procedure offers a faster and more efficient procedure than previous methods such as polishing. The CA method also demonstrated minimal interference effects when tested with varieties of water hardness, ionic strength, common electroactive species (Cu
2+
, Fe
2+
, Fe
3+
, and Cl
−
), and organic matters in aqueous environments. This CA method is easy to use, requires portable equipment, uses reagents that are easily accessible, and does not require extensive sample preparation.
Least squares (LS) is a commonly used pilot-based channel estimation algorithm in orthogonal frequency division multiplexing (OFDM) systems. This algorithm is simple and easy to implement because of ...its low computation complexity. However, it has poor performance, especially at low signal-to-noise ratio (SNR). To solve this problem, an improved LS channel estimation method based on convolutional neural network (CNN) is proposed on the basis of analyzing the traditional LS channel estimation methods. A channel estimation compensated network is designed based on CNN, which can solve the problem of performance degradation of the mean square error (MSE) through the online and offline modules. By designing the input-output relations, training data set, and testing data set, a CNN network is iteratively trained to learn the relevant features of the channels, so that the traditional LS estimation value can be corrected to improve the accuracy. Simulation results show that the proposed method can achieve better performance in bit error rate (BER) and MSE, compared with the traditional channel estimation methods.
Manganese is an emerging concern in drinking water, due to its potential health and aesthetic effects. Although accurate and sensitive, spectroscopic techniques for Mn2+ detection are costly and not ...capable of rapid detection. Electrochemical methods, such as cathodic stripping voltammetry, have been intensively explored as portable low‐cost methods for Mn2+ detection. Challenges of reliability and matrix interference are difficult to overcome with current electrochemical methods. Among the interference reagents, Fe2+ is one of the biggest challenges for Mn2+ detection. Herein, a new method based on multiplex chronoamperometry at potentials between 0.9 and 1.4 V by a multichannel potentiostat is explored for its ability for interference resistance and applicability for Mn2+ detection in real drinking water samples. Compared to conventional one‐channel electrochemical techniques, the multiplex method generates a reliable pattern that is unique to the sample components. The interference between Mn2+ and Fe2+ is investigated and the results are promising even at 100:1 Fe2+:Mn2+ concentrations. The detection limit determined for the multiplex method was 25.3 μM, and the optimum recovery rate in a real drinking water sample was 99.8%.
Graphical : We developed multiplex pattern recognition to determine Mn2+ in water systems using multiple electrodes and chronoamperometry. The proof‐of‐concept study illustrated how patterns could be generated and compared with a pattern library to help measure Mn2+ in the presence of Fe2+. The method can be further expanded to create sophisticated library for dealing with complicated sample matrix in the future.
Abstract
The solid-state forming technology of thermoplastic parts is a new production process developed in recent years. This article uses the Plastic Advisor module to simulate the filling of ...plastic gears and optimize the process parameters. By setting different number of gates, mold temperature and injection temperature, the injection pressure, weld line distribution, air pocket distribution and melt temperature distribution are analyzed, and the best gate number, position and corresponding plastic gear molding are determined. Process parameters to reduce injection molding defects and improve product quality. Combining the simulation analysis results to design the three-dimensional injection mold of the plastic gear, the parametric design of the mold is realized, and the design efficiency of the injection mold is greatly improved.
The Globoidal Indexing Cam Mechanism (Globoidal Indexing Cam Mechanism) is composed of a space cam with a ridge and a turntable with rollers equally divided radially. In this paper, a program for ...reversing the law of motion of the globular indexing cam mechanism is developed, which realizes the computer-aided design and computer-aided processing of the globular indexing cam, and expounds the method of solving the motion law of the driven disc with the idea of reverse design, using UG twice the development tool UG/Open API realizes the parametric modeling of the globular indexing cam, and introduces the process of using the UG software to process the globular indexing cam surface.
Probabilistic Face Embeddings Shi, Yichun; Jain, Anil
2019 IEEE/CVF International Conference on Computer Vision (ICCV),
2019-Oct.
Conference Proceeding
Open access
Embedding methods have achieved success in face recognition by comparing facial features in a latent semantic space. However, in a fully unconstrained face setting, the facial features learned by the ...embedding model could be ambiguous or may not even be present in the input face, leading to noisy representations. We propose Probabilistic Face Embeddings (PFEs), which represent each face image as a Gaussian distribution in the latent space. The mean of the distribution estimates the most likely feature values while the variance shows the uncertainty in the feature values. Probabilistic solutions can then be naturally derived for matching and fusing PFEs using the uncertainty information. Empirical evaluation on different baseline models, training datasets and benchmarks show that the proposed method can improve the face recognition performance of deterministic embeddings by converting them into PFEs. The uncertainties estimated by PFEs also serve as good indicators of the potential matching accuracy, which are important for a risk-controlled recognition system.
Manganese (Mn) was previously considered a mere aesthetic concern that causes colored water and stained surfaces; however, recent epidemiological research found that excessive exposure to Mn has ...neurotoxic effects on humans, especially in children. In response to the health concerns, Health Canada and the World Health Organization moved towards stricter standards on Mn to protect public health. Currently, the standard analytical methods for Mn
2+
are spectroscopic. Although they are highly sensitive, they are not cost effective or portable for high frequency analysis in the field. In this article, the sensitivity of electrochemical techniques, chronoamperometry (CA) and cathodic stripping voltammetry (CSV), are compared as well as the sensitivity of a non-modified glassy carbon screen-printed electrode (GCE SPE) vs a gold nanoparticle modified graphene (AuNPs/GP) coated GCE SPE for Mn
2+
detection and quantification. Regarding the coating of the GCE SPE, detection performed with AuNPs/GP modified GCE SPE shows a wider linear range from 0–520
μ
M and an improved LOD of 0.75
μ
M. Application of the sensors was tested using drinking water samples returning high recovery rates from 92.9 to 106.8% depending on material and method used for Mn
2+
detection and quantification.
Highlights
Mn is a contaminant of emerging concern in drinking water
A portable sensor is developed to determine Mn
2+
in drinking
Comparative study to optimize electrode material and technique for Mn
2+
detection
The use of AuNPs/GP improves the sensitivity of Mn
2+
detection
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