Sensors, Vol. 24, Pages 1930: An Adaptive Radon-Transform-Based Marker Detection and Localization Method for Displacement Measurements Using Unmanned Aerial Vehicles
eyong Pan UAVs have been widely used in deformation monitoring because of their high availability and flexibility. However, the quality of UAV images is affected by changing attitude and surveying environments, resulting in a low monitoring accuracy. Cross-shaped markers are used to improve the accuracy of UAV monitoring due to their distinct center contrast and absence of eccentricity. However, existing methods cannot rapidly and precisely detect these markers in UAV images. To address these problems, this paper proposes an adaptive Radon-transform-based marker detection and localization method for UAV displacement me...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Jianlin Liu Wujiao Dai Yunsheng Zhang Lei Xing Deyong Pan Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1931: Spatial and Temporal Variation of Urban Heat Islands in French Guiana
This study sets the stage for future SUHI studies in French Guiana and aims to contribute to the knowledge needed by decision-makers to achieve sustainable urbanization. (Source: Sensors)
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Gustave Ilunga Jessica Bechet Laurent Linguet Sara Zermani Chabakata Mahamat Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1933: Deep Learning-Based Multi-Class Segmentation of the Paranasal Sinuses of Sinusitis Patients Based on Computed Tomographic Images
This study introduces a multiclass Convolutional Neural Network (CNN) segmentation model by comparing four 3D U-Net variations—normal, residual, dense, and residual-dense. Data normalization and training were conducted on a 40-patient test set (20 normal, 20 abnormal) using 5-fold cross-validation. The normal 3D U-Net demonstrated superior performance with an F1 score of 84.29% on the normal test set and 79.32% on the abnormal set, exhibiting higher true positive rates for the sphenoid and maxillary sinus in both sets. Despite effective segmentation in clear sinuses, limitations were observed in mucosal infla...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Jongwook Whangbo Juhui Lee Young Jae Kim Seon Tae Kim Kwang Gi Kim Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1932: A Novel Three-Point Localization Method for Bladder Volume Estimation
Benpeng Zhu The measurement of bladder volume is crucial for the diagnosis and treatment of urinary system diseases. Ultrasound imaging, with its non-invasive, radiation-free, and repeatable scanning capabilities, has become the preferred method for measuring residual urine volume. Nevertheless, it still faces some challenges, including complex imaging methods leading to longer measurement times and lower spatial resolution. Here, we propose a novel three-point localization method that does not require ultrasound imaging to calculate bladder volume. A corresponding triple-element ultrasound probe has been designed base...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Junru Yuan Mingke Shen Tao Zhang Jun Ou-Yang Xiaofei Yang Benpeng Zhu Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1934: Online Collaborative Perception of Full Bridge Deck Driving Visual of Far Blind Area on Suspension Bridge during Vortex-Induced Vibration
en Yu During a vertical vortex-induced vibration (VVIV), an undulating bridge deck will affect drivers’ sightlines, causing the phenomenon of drifting and changes in the far blind area, thus presenting a potential threat to driving safety. Consequently, to ensure the safety of driving on a suspension bridge deck under VVIV, it is necessary to perceive the far blind spot caused by the occlusion of the driving sightlines under this condition, and to establish an online perception and evaluation mechanism for driving safety. With a long-span suspension bridge experiencing VVIV as the engineering background, ...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Danhui Dan Gang Zeng Xuewen Yu Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1935: Development of Wearable Devices for Collecting Digital Rehabilitation/Fitness Data from Lower Limbs
an-Min Chen Lower extremity exercises are considered a standard and necessary treatment for rehabilitation and a well-rounded fitness routine, which builds strength, flexibility, and balance. The efficacy of rehabilitation programs hinges on meticulous monitoring of both adherence to home exercise routines and the quality of performance. However, in a home environment, patients often tend to inaccurately report the number of exercises performed and overlook the correctness of their rehabilitation motions, lacking quantifiable and systematic standards, thus impeding the recovery process. To address these challenges, the...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Yu-Jung Huang Chao-Shu Chang Yu-Chi Wu Chin-Chuan Han Yuan-Yang Cheng Hsian-Min Chen Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1936: A Deep Learning Approach for Surface Crack Classification and Segmentation in Unmanned Aerial Vehicle Assisted Infrastructure Inspections
ba Mahmoodian Surface crack detection is an integral part of infrastructure health surveys. This work presents a transformative shift towards rapid and reliable data collection capabilities, dramatically reducing the time spent on inspecting infrastructures. Two unmanned aerial vehicles (UAVs) were deployed, enabling the capturing of images simultaneously for efficient coverage of the structure. The suggested drone hardware is especially suitable for the inspection of infrastructure with confined spaces that UAVs with a broader footprint are incapable of accessing due to a lack of safe access or positioning data. The c...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Shamendra Egodawela Amirali Khodadadian Gostar H. A. D. Samith Buddika A. J. Dammika Nalin Harischandra Satheeskumar Navaratnam Mojtaba Mahmoodian Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1937: RU-SLAM: A Robust Deep-Learning Visual Simultaneous Localization and Mapping (SLAM) System for Weakly Textured Underwater Environments
ai Mu Accurate and robust simultaneous localization and mapping (SLAM) systems are crucial for autonomous underwater vehicles (AUVs) to perform missions in unknown environments. However, directly applying deep learning-based SLAM methods to underwater environments poses challenges due to weak textures, image degradation, and the inability to accurately annotate keypoints. In this paper, a robust deep-learning visual SLAM system is proposed. First, a feature generator named UWNet is designed to address weak texture and image degradation problems and extract more accurate keypoint features and their descriptors. Further,...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Zhuo Wang Qin Cheng Xiaokai Mu Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1939: Research on a Cross-Domain Few-Shot Adaptive Classification Algorithm Based on Knowledge Distillation Technology
aonan Dai With the development of deep learning and sensors and sensor collection methods, computer vision inspection technology has developed rapidly. The deep-learning-based classification algorithm requires the acquisition of a model with superior generalization capabilities through the utilization of a substantial quantity of training samples. However, due to issues such as privacy, annotation costs, and sensor-captured images, how to make full use of limited samples has become a major challenge for practical training and deployment. Furthermore, when simulating models and transferring them to actual image scenario...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Jiuyang Gao Siyu Li Wenfeng Xia Jiuyang Yu Yaonan Dai Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1938: Design of a Multi-Position Alignment Scheme
gwen Fu The current new type of inertial navigation system, including rotating inertial navigation systems and three-autonomy inertial navigation systems, has been increasingly widely applied. Benefited by the rotating mechanisms of these inertial navigation systems, alignment accuracy can be significantly enhanced by implementing IMU (Inertial Measurement Unit) rotation during the alignment process. The principle of suppressing initial alignment errors using rotational modulation technology was investigated, and the impact of various component error terms on alignment accuracy of IMU during rotation was analyzed. A co...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Bofan Guan Zhongping Liu Dong Wei Qiangwen Fu Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1941: Estimating Compressive and Shear Forces at L5-S1: Exploring the Effects of Load Weight, Asymmetry, and Height Using Optical and Inertial Motion Capture Systems
This study assesses the agreement of compressive and shear force estimates at the L5-S1 joint using inertial motion capture (IMC) within a musculoskeletal simulation model during manual lifting tasks, compared against a top-down optical motion capture (OMC)-based model. Thirty-six participants completed lifting and lowering tasks while wearing a modified Plug-in Gait marker set for the OMC and a full-body IMC set-up consisting of 17 sensors. The study focused on tasks with variable load weights, lifting heights, and trunk rotation angles. It was found that the IMC system consistently underestimated the compressive forces b...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Iv án Nail-Ulloa Michael Zabala Richard Sesek Howard Chen Mark C. Schall Sean Gallagher Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1940: From Movements to Metrics: Evaluating Explainable AI Methods in Skeleton-Based Human Activity Recognition
This study introduces a perturbation method that produces variations within the error tolerance of motion sensor tracking, ensuring the resultant skeletal data points remain within the plausible output range of human movement as captured by the tracking device. We used the NTU RGB+D 60 dataset and the EfficientGCN architecture for HAR model training and testing. The evaluation involved systematically perturbing the 3D skeleton data by applying controlled displacements at different magnitudes to assess the impact on XAI metric performance across multiple action classes. Our findings reveal that faithfulness may not consiste...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Kimji N. Pellano Inga Str ümke Espen A. F. Ihlen Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1942: Stereo Vision for Plant Detection in Dense Scenes
tstra Automated precision weed control requires visual methods to discriminate between crops and weeds. State-of-the-art plant detection methods fail to reliably detect weeds, especially in dense and occluded scenes. In the past, using hand-crafted detection models, both color (RGB) and depth (D) data were used for plant detection in dense scenes. Remarkably, the combination of color and depth data is not widely used in current deep learning-based vision systems in agriculture. Therefore, we collected an RGB-D dataset using a stereo vision camera. The dataset contains sugar beet crops in multiple growth stages with a v...
Source: Sensors - March 18, 2024 Category: Biotechnology Authors: Thijs Ruigrok Eldert J. van Henten Gert Kootstra Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1929: Ultrasensitive Silicon Photonic Refractive Index Sensor Based on Hybrid Double Slot Subwavelength Grating Microring Resonator
engtai Ma Silicon photonic-based refractive index sensors are of great value in the detection of gases, biological and chemical substances. Among them, microring resonators are the most promising due to their compact size and narrow Lorentzian-shaped spectrum. The electric field in a subwavelength grating waveguide (SWG) is essentially confined in the low-refractive index dielectric, favoring enhanced analyte-photon interactions, which represents higher sensitivity. However, it is very challenging to further significantly improve the sensitivity of SWG ring resonator refractive index sensors. Here, a hybrid waveguide b...
Source: Sensors - March 17, 2024 Category: Biotechnology Authors: Kaiwei Lu Beiju Huang Xiaoqing Lv Zan Zhang Zhengtai Ma Tags: Article Source Type: research

Sensors, Vol. 24, Pages 1920: Ultralow-Noise Chopper Amplifier for Seafloor E-Field Measurement
In this study, a chopper amplifier was proposed and developed to measure the seafloor E-field signal in the nanovolt to millivolt range at significantly low frequencies. It included a modulator, transformer, AC amplifier, high-impedance (hi-Z) module, demodulator, low-pass filter, and chopper clock generator. The injected charge in complementary metal-oxide semiconductor (CMOS) switches that form the modulator is the main source of 1/f noise. Combined with the principles of peak filtering and dead bands, a hi-Z module was designed to effectively reduce low-frequency noise. The chopper amplifier achieved an ultralow voltage...
Source: Sensors - March 17, 2024 Category: Biotechnology Authors: Sixuan Song Kai Chen Tags: Article Source Type: research