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Recently, object detection has become a research hotspot in computer vision, which often detects regular images with small viewing angles. In order to obtain a field of view without blind spots, fisheye cameras, which have distortions and discontinuities, have come into use. The fisheye camera, which has a wide viewing angle, and an unmanned aerial vehicle equipped with a fisheye camera are used to obtain a field of view without blind spots. However, distorted and discontinuous objects appear in the captured fisheye images due to the unique viewing angle of fisheye cameras. It poses a significant challenge to some existing object detectors. To solve this problem, this paper proposes a PGDS-YOLOv8s model to solve the issue of detecting distorted and discontinuous objects in fisheye images. First, two novel downsampling modules are proposed. Among them, the Max Pooling and Ghost's Downsampling (MPGD) module effectively extracts the essential feature information of distorted and discontinuous objects. The Average Pooling and Ghost's Downsampling (APGD) module acquires rich global features and reduces the feature loss of distorted and discontinuous objects. In addition, the proposed C2fs module uses Squeeze-and-Excitation (SE) blocks to model the interdependence of the channels to acquire richer gradient flow information about the features. The C2fs module provides a better understanding of the contextual information in fisheye images. Subsequently, an SE block is added after the Spatial Pyramid Pooling Fast (SPPF), thus improving the model's ability to capture features of distorted, discontinuous objects. Moreover, the UAV-360 dataset is created for object detection in fisheye images. Finally, experiments show that the proposed PGDS-YOLOv8s model on the VOC-360 dataset improves mAP@0.5 by 19.8% and mAP@0.5:0.95 by 27.5% compared to the original YOLOv8s model. In addition, the improved model on the UAV-360 dataset achieves 89.0% for mAP@0.5 and 60.5% for mAP@0.5:0.95. Furthermore, on the MS-COCO 2017 dataset, the PGDS-YOLOv8s model improved AP by 1.4%, AP 50 by 1.7%, and AP 75 by 1.2% compared with the original YOLOv8s model. [ABSTRACT FROM AUTHOR]

One of the bottleneck issues for commercial scale-up of Ti additive manufacturing lies in high cost of raw material, i.e. the spherical Ti powder that is often made by gas atomization. In this study, we address this significant issue by way of powder modification & ball milling processing, which shows that it is possible to produce printable Ti powders based on ultra-low cost, originally unprintable hydrogenation-dehydrogenation (HDH) Ti powder. It is also presented that the as-printed Ti using the modified powder exhibits outstanding mechanical properties, showing a combination of excellent fracture strength (~895 MPa) and high ductility (~19.0% elongation).

Environmental information disclosure is critical avenue for stakeholders to gauge the fulfillment of corporate environmental responsibilities, as well as a key path for companies to gain social reputation and achieve sustainable development. To achieve both economic and social sustainability and improve the environmental information disclosure by private firms, this study delves into the impact mechanism and realization path of mixed ownership reform on environmental information disclosure among Chinese private enterprises listed between 2010 and 2020. Utilizing a panel fixed effect model, we scrutinize the interplay between state capital involvement and the disclosure of environmental information by private enterprises. Our findings reveal that state capital involvement may encourage private enterprises to disclose environmental information through resource allocation and governance improvements. The higher the shareholding ratio of state-owned participating shareholders, the more it helps private firms to disclose environmental information. State-owned shareholders play a pivotal role in the appointment of supervisors, directors, and executives, effectively improving corporate governance mechanisms and positively moderates how private companies with state-owned capital participate in disclosing environmental information. Moreover, the magnitude of media coverage and the public opinion pressure faced by private enterprises further amplify the influence of state-owned capital involvement on environmental information disclosure. Additionally, our research reveals that corporate profitability partially interplays with the effects of state-owned capital disclosure of environmental information by private companies. According to the research results, we recommend that the government proactively promote mixed ownership reform with private enterprises as the main participants, fully leveraging the resource advantages and influence of state-owned capital. At the same time, it is imperative to strengthen the governance effect of internal state-owned shareholders and external public opinion supervision in private enterprises. Enhancing profitability is also identified as a key driver for private enterprises to engage in more robust environmental information disclosure practices. [ABSTRACT FROM AUTHOR]