The rapid advancements in deep learning have revolutionized the field of computer vision. However, despite the significant progress in computer vision, there remains a scarcity of research focused on utilizing this technology for distance estimation. Exploring such studies can bring immense convenience to people, especially in applications like anomaly object detection. On that account, this research proposes an improved detection model based on You Only Look Once version 8 (YOLOv8) namely YOLOv8-CAW, which is capable of both detecting target objects and accurately calculating their distances. The proposed method involves incorporating the Coordinate Attention and Wise-IoU into the YOLOv8 network, enhancing the detection accuracy. Combined with the distance estimation algorithm, results in a comprehensive output that includes both detection results and calculated distances. At the end of the experiment, a substantial improvement in performance metrics was observed, the model achieved increases in recall (0.4%), precision (2.2%), and Mean Average Precision (mAP) (1.5%) within the 0.5 to 0.95 threshold range, while maintaining inference speeds similar to the baseline model in PASCAL VOC dataset. Besides that, distance estimation achieved an approximate average accuracy of 90% which shows the results are highly encouraging and promising. The successful integration of computer vision and distance estimation opens new possibilities for practical applications, showcasing the potential of this approach in real-world scenarios.
In this paper, we review the highly promising silica glass, fabricated as doped and undoped optical fiber for intended use in radiation dosimetry. The dosimetry techniques reviewed here, underpinned by intrinsic and extrinsic defects in silica glass, focus on Thermoluminescence (TL), Optically Stimulated Luminescence (OSL) and Radioluminescence (RL), with occasional references to the much more established Radiation Induced Attenuation (RIA). The other focus in this review is on the various materials that have been reported earlier as dopants and modifiers used in silica glass optical fiber radiation dosimeters. This article also elaborates on recently reported optical fiber structures, namely, cylindrical fibers, photonic crystal fibers and flat fibers, as well as dimensions and shapes used for optimization of dosimeter performance. The various types of optical fiber radiation dosimeters are subsequently reviewed for various applications ranging from medical dosimetry such as in external beam radiotherapy, brachytherapy and diagnostic imaging, as well as in industrial processing and space dosimetry covering a dynamic dose range from μGy to kGy. Investigated dosimetric characteristics include reproducibility, fading, dose response, reciprocity between luminescence yield to dose-rate and energy dependence. The review is completed by a brief discussion on limitations and future developments in optical fiber radiation dosimetry.
A dual-channel propagation controlled photonic crystal fiber (PCF)-based plasmonic sensor was presented to detect multiple analytes simultaneously. Plasmonic micro-channels were placed on the outer surface of the PCF, which facilitates an easy sensing mechanism. The sensor was numerically investigated by the finite element method (FEM) with the perfectly matched layer (PML) boundary conditions. The proposed sensor performances were analyzed based on optimized sensor parameters, such as confinement loss, resonance coupling, resolution, sensitivity, and figure of merit (FOM). The proposed sensor showed a maximum wavelength sensitivity (WS) of 25,000 nm/refractive index unit (RIU) with a maximum sensor resolution (SR) of 4.0 × 10−6 RIU for channel 2 (Ch-2), and WS of 3000 nm/RIU with SR of 3.33 × 10−5 RIU for channel 1 (Ch-1). To the best of our knowledge, the proposed sensor exhibits the highest WS compared with the previously reported multi-analyte based PCF surface plasmon resonance (SPR) sensors. The proposed sensor could detect the unknown analytes within the refractive index (RI) range of 1.32 to 1.39 in the visible to near infrared region (550 to 1300 nm). In addition, the proposed sensor offers the maximum Figure of Merit (FOM) of 150 and 500 RIU−1 with the limit of detection (LOD) of 1.11 × 10−8 RIU2/nm and 1.6 × 10−10 RIU2/nm for Ch-1 and Ch-2, respectively. Due to its highly sensitive nature, the proposed multi-analyte PCF SPR sensor could be a prominent candidate in the field of biosensing to detect biomolecule interactions and chemical sensing.
1 November 2014 in Radiation Physics and Chemistry