A surface defect detection method of steel plate based on YOLOV3

At present, the steel plate surface defect detection technology based on machine vision and convolutional neural network (CNN) has achieved good results. However, these models are mostly two-stage methods, extracting features first and then classifying them, which is slow and inaccurate. Therefore, this paper proposes a single-stage surface defect detection method of steel plate based on yolov3, which can classify defects, determine the location of defects, and greatly improve the detection speed. It is of great significance to realize the automation of cold rolling production line. The experiment shows that the detection speed of this model reaches 62 fps and the accuracy reaches 73 %, which has a good prospect in industry

A surface defect detection method of steel plate based on YOLOV3

At present, the steel plate surface defect detection technology based on machine vision and convolutional neural network (CNN) has achieved good results. However, these models are mostly two-stage methods, extracting features first and then classifying them, which is slow and inaccurate. Therefore, this paper proposes a single-stage surface defect detection method of steel plate based on yolov3, which can classify defects, determine the location of defects, and greatly improve the detection speed. It is of great significance to realize the automation of cold rolling production line. The experiment shows that the detection speed of this model reaches 62 fps and the accuracy reaches 73 %, which has a good prospect in industry

Ultrasonic measurement of lubricant film thickness distribution of journal bearing

Most film thickness measurement methods damage the working surface of a bearing and cannot measure the minimum film thickness, making it difficult to reveal the lubrication state and warn of wear. Two non-intrusive ultrasonic methods were proposed for measuring the film thickness distribution of the bearing, i.e., the full circumferential measurement and the prediction based on limited measuring points. The ultrasonic recognition model of film thickness was built. A film thickness measuring device and its calibration device were constructed. A calibration experiment in the range of 1–150 µm and a measurement experiment of the bearing’s film thickness distribution were carried out. The results showed that in the calibration range, the relative error of most recognition values was less than ±5%, and some are less than 3%. The identification accuracy of the spring model has a zoned phenomenon. The relative difference between the experimental and the simulated values of the film thickness was less than 8% under most working conditions. The predicted values of eccentricity, attitude angle, and minimum film thickness have a small difference from the simulated values, indicating that the accuracy of the measurement method is high

Evolution of tourism in a flagship protected area of China

Nature-based tourism in protected areas, which is growing worldwide, offers much potential to enhance biodiversity conservation, poverty alleviation, and ultimately sustainable development. Understanding the evolution of protected areas as tourism destinations and the causes and consequences of changing supply and demand elements is an essential step toward sustainably managing tourism in these critical ecosystems. This research applied the Tourism Area Life Cycle (TALC) model to illustrate and analyze the 30-year evolution of tourism in Wolong Nature Reserve. Being inscribed in UNESCO Biosphere Reserve and World Heritage programmes, Wolong is a flagship protected area in China. We showed that the Reserve experienced exploration, involvement, and development stages of the TALC before tourism growth was completely halted by the Wenchuan Earthquake in 2008. We systematically investigated the changes related to the evolution of tourism and identified various internal and external driving forces. We examined the dynamics of politics, economy, and tourism growth that might propel the Reserve through the life cycle and identified significant tourism governance structural changes through the stages. The results have implications for sustainable tourism development in China's protected areas and also contribute to a broader and general understanding of the complex relationships between protected areas, sustainable tourism, and community development

High-Performance Light Field Reconstruction with Channel-wise and SAI-wise Attention

© Springer Nature Switzerland AG 2019. Light field (LF) images provide rich information and are suitable for high-level computer vision applications. To acquire capabilities of modeling the correlated information of LF, most of the previous methods have to stack several convolutional layers to improve the feature representation and result in heavy computation and large model sizes. In this paper, we propose channel-wise and SAI-wise attention modules to enhance the feature representation at a low cost. The channel-wise attention module helps to focus on important channels while the SAI-wise attention module guides the network to pay more attention to informative SAIs. The experimental results demonstrate that the baseline network can achieve better performance with the aid of the attention modules

Microbial biomass carbon and enzyme activities of urban soils in Beijing

Introduction To promote rational and sustainable use of soil resources and to maintain the urban soil quality, it is essential to assess urban ecosystem health. In this study, the microbiological properties of urban soils in Beijing and their spatial distribution patterns across the city were evaluated based on measurements of microbial biomass carbon and urease and invertase activities of the soils for the purpose of assessing the urban ecosystem health of Beijing. Materials and methods Grid sampling design, normal Kriging technique, and the multiple comparisons among different land use types were used in soil sampling and data treatment. The inherent chemical characteristics of urban soils in Beijing, e.g., soil pH, electronic conductivity, heavy metal contents, total N, P and K contents, and soil organic matter contents were detected. The size and diversity of microbial community and the extent of microbial activity in Beijing urban soils were measured as the microbial biomass carbon content and the ratio of microbial biomass carbon content to total soil organic carbon. Results and discussion The microbial community health measured in terms of microbial biomass carbon, urease, and invertase activities varied with the organic substrate and nutrient contents of the soils and were not adversely affected by the presence of heavy metals at p < 0.01. It was shown that the older and the biologically more stable part of city exhibited higher microbial activity levels than the more recently developed part of the city and the road areas of heavy traffic. It was concluded that the land use patterns in Beijing urban soils influenced the nature and activities of the microbial communities

Heat conduction in graphene flakes with inhomogeneous mass interface

Using nonequilibrium molecular dynamics simulations, we study the heat conduction in graphene flakes composed by two regions. One region is mass-loaded and the other one is intact. It is found that the mass interface between the two regions greatly decreases the thermal conductivity, but it would not bring thermal rectification effect. The dependence of thermal conductivity upon the heat flux and the mass difference ratio are studied to confirm the generality of the result. The interfacial scattering of solitons is studied to explain the absence of rectification effect.Comment: 5 pages, 4 figure