Journal of Measurements in Engineering

Journal of Measurements in Engineering, (in Press).Lijun Mao, Tianxiang Zhou, Chenghui NanThe increasing of forest fires highlights the importance of rapidly and accurately quantifying the burned areas, which is crucial evidence for determining the cause of fire and assigning responsibility. This study develops an operational tool based on the cloud-computing abilities of the PIE-Engine platform and Sentinel-2 satellite imagery. The burned areas are rapidly extracted by applying differential spectral indices such as dNDVI, dNBR and dNBR2 using the adaptive thresholds determined by the Otsu algorithm. Compared with field investigations, the accuracy of using a wildfire case in Liuhe Village, Hubei Province is high. The findings indicate that dNBR can achieve an area accuracy of 98.22 % and a pixel-level F1-score of 0.94, significantly higher than dNDVI. Although the accuracy of the random forest model is slightly high, the dNBR based method achieves an excellent balance between computational efficiency (about 2 s of processing time) and accuracy. In addition, we have developed a user-friendly web application that allows for custom parameter settings and visualizes results as a quantitative burned area map. This tool only requires a web browser, greatly reducing the technical barriers of remote sensing applications and providing a transparent, efficient, and accessible solution for supporting forest fire investigation and emergency response.

Journal of Measurements in Engineering, (in Press).Anmin Jiang, Daobing Zhang, Feifei Wang, Yanchen Dong, Huadong Yin, Huzhi Wang, Sheng Zhang, Zhicheng Duan, Shaoxiang XieThe engineering disasters caused by fault structural zones represent a persistent challenge in geotechnical engineering. This study employs an integrated approach, combining multi-temporal remote sensing, field investigation, and numerical simulation, to investigate the deformation mechanisms and stability of an open-pit slope controlled by the F15 fault. The results demonstrate that the collapse of the northern slope results from the combined effect of the internal F15 fault structure and external unloading due to underground mining. Remote sensing imagery reveals a four-stage failure process: initial rock deformation, local landslides, local surface subsidence, and final surface subsidence. Significantly, the F15 structural zone alters the deformation trend of the upper slope, channeling displacement towards the eastern valley, with a maximum simulated displacement of 5.4 cm. The safety factor of the slope, calculated using the strength reduction method, is 1.45, and the potential sliding surface is identified as the F15 structural zone. While the slope is currently stable, the limited safety redundancy and observed local landslides highlight the need for targeted monitoring and reinforcement of the fault zone. This study provides data-supported insights for the prevention and control of geological disasters in similar fault-controlled mining slopes.

Journal of Measurements in Engineering, (in Press).Pinxiao Liu, Deping Liu, Guangyu Cai, Jisen Yan, Zhenyang Liu, Haonan Liu, Kai LiQ235 low-carbon steel is widely used in construction, bridges, machinery manufacturing and other fields because of its good plasticity and weldability. To explore the optimized application of laser welding technology in Q235 steel processing, this study used an EEF-LWM-1500 welding machine and systematically investigated the effect of different welding speeds on the joint quality of Q235 steel under the condition of a constant laser power of 1200 W. The weld quality was systematically evaluated through multiple characterization methods, including metallographic microscopy, scanning electron microscopy, tensile testing, microhardness measurement, electrochemical corrosion tests, and friction-wear experiments. Experimental results indicated that a welding speed of 120 mm/min caused burn-through in the steel plate, while increasing the speed to 240 mm/min achieved good joint formability. Notably, the heat-affected zone gradually decreased with higher welding speeds. The hardness and tensile strength of the laser-welded zone both exceeded those of the base material. Specifically, the average hardness of the weld zone peaked at 177.56 HV when the welding speed was 500 mm/min. Below this speed, hardness increased with rising welding speed, while it tended to decrease above 500 mm/min. Tensile strength showed a similar trend, with the highest value of 424.98 MPa and the lowest value of 421.94 MPa. Electrochemical corrosion tests revealed that the welded joint at 500 mm/min exhibited the smallest self-corrosion current density (1.41×10⁻5 A/cm2) and the largest capacitive arc radius, confirming optimal corrosion resistance. This study identifies that the optimal laser welding speed for Q235 steel is 500 mm/min, which provides important technical references for improving the welding quality and production efficiency of Q235 steel in practical production and expanding its application scope.

Journal of Measurements in Engineering, (in Press).Qinggui Hu, Xinlong ZhangIn 2008, we proposed the “New Experimental Scheme for Measuring the Gravitational Constant G between Large-Mass Objects”. In 2021, this scheme was implemented, yielding a new value of G: 9.09×10-9 N·m2/kg2. By contrast, the currently internationally recognized value is 6.67259×10-11 N·m2/kg2. The discrepancy between these two values is so significant that it cannot be adequately explained by traditional theories. To address this issue, a permanent experimental platform was established in early June 2023 at the new campus of Neijiang Normal University, enabling a repeat of the experiment. Based on this platform, an additional experimental measurement was conducted, resulting in a new G value of 7.3827302×10-10 N·m2/kg2. Subsequently, we analyzed the causes of the significant difference between the latest measured value and the first one. And we also performed a comparative analysis between the new experiment and the traditional Cavendish torsion balance experiment. The results demonstrated that the new experimental system features fewer error sources and higher stability. These new G values suggest that the gravitational constant may not be a true constant; instead, it could be related to factors such as the shape and density of objects etc.

Journal of Measurements in Engineering, (in Press).Renyuan Wu, Xinyi Chen, Yuanmeng Wang, Ruoqi Wu, Shuangli WangTo address inaccurate strawberry recognition caused by cluttered field environments such as varying illumination, occlusion and uneven distribution, an improved lightweight model YOLOv7-SSC for strawberry ripeness detection was proposed. First, the backbone network of YOLOv7 is replaced with ShuffleNetV2, a lightweight feature extraction network, to significantly reduce the number of model parameters. Second, the lightweight network Slim-neck is used as the neck structure to reduce model complexity while preserving high precision. Finally, the Content Perception Feature Recombination (CARAFE) upsampling is used to enlarge receptive field in the feature fusion network and fully leverage semantic information. Moreover, the pictures of the strawberry dataset with three common conditions (unripe strawberry, near ripe strawberry and ripe strawberry) were collected in real picking environment. The experimental results show that compared to the original YOLOv7 model, the improved model parameters are reduced by 69.0 %, the floating point number is decreased by 79.4 %, and the accuracy rate reaches 99.6 %. These results demonstrate that YOLOv7-SSC model can achieve fast recognition of strawberry maturity while maintaining high precision, making it more suitable for small target detection in complex field compared with other algorithms.