Text-based Person Search in Full Images via Semantic-Driven Proposal Generation

Finding target persons in full scene images with a query of text description has important practical applications in intelligent video surveillance.However, different from the real-world scenarios where the bounding boxes are not available, existing text-based person retrieval methods mainly focus on the cross modal matching between the query text descriptions and the gallery of cropped pedestrian images. To close the gap, we study the problem of text-based person search in full images by proposing a new end-to-end learning framework which jointly optimize the pedestrian detection, identification and visual-semantic feature embedding tasks. To take full advantage of the query text, the semantic features are leveraged to instruct the Region Proposal Network to pay more attention to the text-described proposals. Besides, a cross-scale visual-semantic embedding mechanism is utilized to improve the performance. To validate the proposed method, we collect and annotate two large-scale benchmark datasets based on the widely adopted image-based person search datasets CUHK-SYSU and PRW. Comprehensive experiments are conducted on the two datasets and compared with the baseline methods, our method achieves the state-of-the-art performance

Design and Application of Partial Immersion Focused Ultrasonic Transducers for Austenitic Weld Inspection

Austenitic stainless steel is a widely used material in the industry, and the welding technique enables stainless steel components to have different shapes for different applications. Any flaws in the weld will degrade the performance of the austenitic component; thus, it is essential to ultrasonically and nondestructively test flaws in welds to ensure service safety. Recently, weld inspection has been performed using contact transducers, but missed detections or false positives for flaws in welds usually occur due to a poor coupling condition in the detection, a low signal-to-noise ratio, and instantaneous noises. In this study, a partial immersion focused (PIF) ultrasonic transducer is designed and used for austenitic weld inspection to address the above issues. The detailed design and manufacture of the PIF transducer are described, and the advantages of the transducer are shown by comparing the results detected using different kinds of transducers. In addition, in order to suppress false positives, a B-image method optimized using a time-dependent threshold is proposed. Experiments are performed to detect flaws in a welded specimen. All the artificial flaws are evaluated using the developed transducer and the proposed method, but minor flaws are mis-detected when planar transducers are used, verifying the method proposed in this paper

Biochar produced from tobacco stalks, eggshells, and Mg for phosphate adsorption from a wide range of pH aqueous solutions

Preparing biochar from tobacco stalks modified with Mg is a feasible way to utilize tobacco stalks as a resource. However, the capacity of phosphate removal of Mg-biochar is affected greatly with increasing pH. In the present work, biochar produced from the tobacco stalks was modified via Mg addition and eggshells during the preparation for improving the phosphate adsorption performance at higher pH. The results revealed that the theoretical maximum adsorption capacity of phosphate for the biochar increased from 110.62 to 272.37 mg P/g when the mass ratio of Mg to tobacco stalk increased from 0.12:1 to 0.48:1 (M-C). The adsorption capacity of the biochar with a mass ratio of 0.3:1 (M-C2) was more than 200 mg P/g in the pH range of 3 to 7 but with further increase of pH from 7 to 12 the capacity decreased from 205 to 135.2 mg P g ^−1 . Addition of eggshells with the magnesium solution during the dipping process can effectively improve the capacity of the modified biochar for phosphate in the alkaline condition. When the mass ratio of eggshell to tobacco stalk was ≥0.25:1, the phosphate adsorption capacities of the biochar can reach above 200 mg P/g within a wide pH range of 3 to 12, and the maximum adsorption capacity can reach more than 270 mg P g ^−1 for the mass ratio of 1:1 (EM-C24). The characterization results demonstrated that Ca and Mg were loaded on the biochar. The high adsorption performance provides reference values for the utilization of tobacco stalks and eggshells