Enhanced Minutiae Extraction for High-Resolution Palmprint Recognition

International audienceA palmprint generally possesses about 10 times more minutiae features than a fingerprint, which could provide reliable biometric-based personal authentication. However, wide distribution of various creases in a palmprint creates a number of spurious minutiae. Precisely and efficiently, minutiae extraction is one of the most critical and challenging work for high-resolution palmprint recognition. In this paper, we propose a novel minutiae extraction and matching method for high-resolution palmprint images. The main contributions of this work include the following. First, a circle-boundary consistency is proposed to update the local ridge orientation of some abnormal points. Second, a lengthened Gabor filter is designed to better recover the discontinuous ridges corrupted by wide creases. Third, the principal ridge orientation of palmprint image is calculated to establish an angle alignment system, and coarse-to-fine shifting is performed to obtain the optimal coordinate translation parameters. Following these steps, minutiae matching can be efficiently performed. Experiment results conducted on the public high-resolution palmprint database validate the effectiveness of the proposed method

A Multifeature Learning and Fusion Network for Facial Age Estimation

Age estimation from face images has attracted much attention due to its favorable and many real-world applications such as video surveillance and social networking. However, most existing studies usually learn a single kind of age feature and ignore other appearance features such as gender and race, which have a great influence on the age pattern. In this paper, we proposed a compact multifeature learning and fusion method for age estimation. Specifically, we first used three subnetworks to learn gender, race, and age information. Then, we fused these complementary features to further form more robust features for age estimation. Finally, we engineered a regression-ranking age-feature estimator to convert the fusion features into the exact age numbers. Experimental results on three benchmark databases demonstrated the effectiveness and efficiency of the proposed method on facial age estimation in comparison to previous state-of-the-art methods. Moreover, compared with previous state-of-the-art methods, our model was more compact with only a 20 MB memory overhead and is suitable for deployment on mobile or embedded devices for age estimation

Enhanced Minutiae Extraction for High-Resolution Palmprint Recognition

International audienceA palmprint generally possesses about 10 times more minutiae features than a fingerprint, which could provide reliable biometric-based personal authentication. However, wide distribution of various creases in a palmprint creates a number of spurious minutiae. Precisely and efficiently, minutiae extraction is one of the most critical and challenging work for high-resolution palmprint recognition. In this paper, we propose a novel minutiae extraction and matching method for high-resolution palmprint images. The main contributions of this work include the following. First, a circle-boundary consistency is proposed to update the local ridge orientation of some abnormal points. Second, a lengthened Gabor filter is designed to better recover the discontinuous ridges corrupted by wide creases. Third, the principal ridge orientation of palmprint image is calculated to establish an angle alignment system, and coarse-to-fine shifting is performed to obtain the optimal coordinate translation parameters. Following these steps, minutiae matching can be efficiently performed. Experiment results conducted on the public high-resolution palmprint database validate the effectiveness of the proposed method

Recent progress and perspective of cathode recycling technology for spent LiFePO4 batteries

Due to the shortage of fossil fuels and increasing environmental pressures, the Li-ion battery industry is developing rapidly. Currently, most electric vehicles are powered by lithium iron phosphate batteries, and a lot of lithium–iron phosphate batteries will be retired after the cycle life termination. If not addressed promptly, they will pollute the environment and waste metal resources. The recycling spent batteries holds immense significance for environmental protection and resource recycling. This article provides a comprehensive review on the current state of waste LiFePO 4 cathode materials from four perspectives: pretreatment, wet recovery, direct regeneration, and production of high-value-added products. Furthermore, it compares their respective advantages and disadvantages.</p

Co/carbon nanofiber with adjustable size and content of Co nanoparticles for tunable microwave absorption and thermal conductivity

Electromagnetic pollution and heat dissipation problems are becoming increasingly worthy of attention due to the rapid development of electronic devices, which puts forward an urgent demand for microwave absorbers with excellent thermal management performance. Herein, high-performance Co/carbon nanofiber (Co/CNF) microwave absorbers with high thermal conductivity were fabricated by facile step-by-step method. The microwave absorption properties can be readily tuned by adjusting the content and size of Co nanoparticles through concentration gradient adsorption. Benefiting from the formation of dielectric and magnetic coupling network, Co/CNF composites possess intensive dipole polarization, interface polarization, and magnetic loss. The optimal Co/CNF composites exhibit outstanding microwave absorption performance with a minimum reflection loss (RL) of −53.0 dB at 11.44 GHz, and a maximum effective absorption bandwidth (EAB) of 5.5 GHz. In addition, the thermal conductivities of the Co/CNF-natural rubber (Co/CNF-NR) composites are significantly improved. This work may inspire the exploration of high-efficiency heat-conduction microwave absorbers based on CNF