Towards Scalable 3D Anomaly Detection and Localization: A Benchmark via 3D Anomaly Synthesis and A Self-Supervised Learning Network

Recently, 3D anomaly detection, a crucial problem involving fine-grained geometry discrimination, is getting more attention. However, the lack of abundant real 3D anomaly data limits the scalability of current models. To enable scalable anomaly data collection, we propose a 3D anomaly synthesis pipeline to adapt existing large-scale 3Dmodels for 3D anomaly detection. Specifically, we construct a synthetic dataset, i.e., Anomaly-ShapeNet, basedon ShapeNet. Anomaly-ShapeNet consists of 1600 point cloud samples under 40 categories, which provides a rich and varied collection of data, enabling efficient training and enhancing adaptability to industrial scenarios. Meanwhile,to enable scalable representation learning for 3D anomaly localization, we propose a self-supervised method, i.e., Iterative Mask Reconstruction Network (IMRNet). During training, we propose a geometry-aware sample module to preserve potentially anomalous local regions during point cloud down-sampling. Then, we randomly mask out point patches and sent the visible patches to a transformer for reconstruction-based self-supervision. During testing, the point cloud repeatedly goes through the Mask Reconstruction Network, with each iteration's output becoming the next input. By merging and contrasting the final reconstructed point cloud with the initial input, our method successfully locates anomalies. Experiments show that IMRNet outperforms previous state-of-the-art methods, achieving 66.1% in I-AUC on Anomaly-ShapeNet dataset and 72.5% in I-AUC on Real3D-AD dataset. Our dataset will be released at https://github.com/Chopper-233/Anomaly-ShapeNe

Study on the adaptability and optimization of boom replacement methods for suspension bridges

To ensure the safe operation of bridges, the study of methods and techniques for boom replacement has become a crucial aspect of the scientific maintenance of suspension bridges. This study focuses on analyzing the bridge responses and evaluating the applicability of three different boom replacement methods: single-point, three-point and five-point, using finite element calculations. A sea-crossing suspension bridge is taken as a case study to simulate the process of boom replacement using temporary booms. Consequently, the optimal replacement method for booms of varying lengths is determined. Meanwhile, this research proposes a quantitative basis for classifying boom lengths based on calculation data and analysis results to determine the suitable boom lengths for different replacement methods. Besides, a comparison of the relationship between the force transmission efficiency of temporary booms and boom length reveals that longer booms exhibit lower force transmission efficiency, with the efficiency decreasing at a faster rate as boom length increases. Overall, these findings provide a theoretical basis for the study of boom replacement in suspension bridges

Preparation and properties of the specific anti-influenza virus transfer factor

Specific anti-influenza virus and normal transfer factors prepared in an experimental animal model, the pig, have been tested for their components, characteristics, and activity of known specificity. Two transfer factors are small molecular mixture which consist entirely or partly of polypeptides and polynucleosides. Moreover, the biological activity of transfer factors could be approved by Rosettes test and specific skin test. The study would lay a foundation for the research and development of other specific transfer factor

Investigation of Glucose Non-Invasive Measurement Based on NIR Laser

Near-infrared (NIR) diffuse reflectance spectroscopy represents a feasible and promising approach to the noninvasive prediction of blood glucose concentration. This paper experimentally studied and proposed a novel method to develop a stand-alone measurement system, in which laser beams at several particular wavelengths are collimated and illuminated a sample with low-energy NIR by an optical fibre probe, and the diffused reflectance from the sample is collected by a detector. The experimental scheme of the measurement system has been demonstrated to be reasonable and suitable for detecting the change of diffuse reflected absorbance from phantoms and finger tissue. The experimental results have presented the good correlation between the diffuse reflected absorbance and glucose concentration at several particular wavelengths. The spectra lines are perfectly separate from each other at different glucose concentration in vitro. Obvious differences exist in the diffuse reflected absorbance for different glucose concentration. According to the testing standard of the Oral Glucose Tolerance Test (OGTT), the dynamic changes, which the diffuse reflected absorbance from tissue is accompanied with the change of the glucose concentration, have been explored by taking a certain amount oral glucose solution. The results have presented that the sensing system proposed is already able to sense the glucose change from fingertip tissue though the overlapping spectra are encountered. Also, the temperature effect of the sample on the diffuse reflected absorbance of the glucose has been taken into consideration