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Technologies, Volume 13, Issue 1 (January 2025) – 13 articles

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14 pages, 1670 KiB  
Article
Analysis of Multidimensional Clinical and Physiological Data with Synolitical Graph Neural Networks
by Mikhail Krivonosov, Tatiana Nazarenko, Vadim Ushakov, Daniil Vlasenko, Denis Zakharov, Shangbin Chen, Oleg Blyus and Alexey Zaikin
Technologies 2025, 13(1), 13; https://doi.org/10.3390/technologies13010013 (registering DOI) - 28 Dec 2024
Viewed by 1
Abstract
This paper introduces a novel approach for classifying multidimensional physiological and clinical data using Synolitic Graph Neural Networks (SGNNs). SGNNs are particularly good for addressing the challenges posed by high-dimensional datasets, particularly in healthcare, where traditional machine learning and Artificial Intelligence methods often [...] Read more.
This paper introduces a novel approach for classifying multidimensional physiological and clinical data using Synolitic Graph Neural Networks (SGNNs). SGNNs are particularly good for addressing the challenges posed by high-dimensional datasets, particularly in healthcare, where traditional machine learning and Artificial Intelligence methods often struggle to find global optima due to the “curse of dimensionality”. To apply Geometric Deep Learning we propose a synolitic or ensemble graph representation of the data, a universal method that transforms any multidimensional dataset into a network, utilising only class labels from training data. The paper demonstrates the effectiveness of this approach through two classification tasks: synthetic and fMRI data from cognitive tasks. Convolutional Graph Neural Network architecture is then applied, and the results are compared with established machine learning algorithms. The findings highlight the robustness and interpretability of SGNNs in solving complex, high-dimensional classification problems. Full article
15 pages, 5720 KiB  
Article
A Novel Vibration Suppression Method for Welding Robots Based on Welding Pool Instability Evaluation and Trajectory Optimization
by Mingtian Ma, Hong Lu, Yongquan Zhang, Zidong Wu, He Huang, Xujie Yuan, Xu Feng, Zhi Liu and Zhangjie Li
Technologies 2025, 13(1), 12; https://doi.org/10.3390/technologies13010012 (registering DOI) - 28 Dec 2024
Viewed by 26
Abstract
Industrial robots are widely used in welding operations because of their high production efficiency. The structure of the robot and the complex stress conditions during welding operations lead to the vibration of the end of robot, which leads to welding defects. However, current [...] Read more.
Industrial robots are widely used in welding operations because of their high production efficiency. The structure of the robot and the complex stress conditions during welding operations lead to the vibration of the end of robot, which leads to welding defects. However, current vibration suppression techniques for welding robots usually only consider the robotic performance while overlooking their impact on the welding metal forming process. Therefore, based on the influence of robot vibration on welding pool stability during the welding process, a new welding robot vibration suppression method is proposed in this paper, along with the establishment of a welding pool stability assessment model. The proposed vibration suppression algorithm is based on the optimization of the welding trajectory. To enhance the performance of the method, the Particle Swarm Optimization (PSO) algorithm is applied to optimize the joint angular velocity and angular acceleration. Finally, robot welding experiments are designed and conducted. By comparing vibration measurement data and welding quality before and after the vibration suppression, the effectiveness and stability of the proposed method are validated. Full article
14 pages, 3540 KiB  
Article
Inhibition of Anti-Reflection Film Cracks on Plastic Substrates Using Nanolaminate Layer Deposition in Plasma-Enhanced Atomic Layer Deposition
by Chi-Chieh Wang, Cheng-Fu Wang, Meng-Chi Li, Li-Chen Su and Chien-Cheng Kuo
Technologies 2025, 13(1), 11; https://doi.org/10.3390/technologies13010011 (registering DOI) - 28 Dec 2024
Viewed by 64
Abstract
In this research, we mainly increase the adhesion of PMMA substrate and film, which is reflected in the environmental test. This study used plasma-enhanced atomic layer deposition (PEALD) to find the relationship between the intensity of XRD reflection peak and the root-mean-square surface [...] Read more.
In this research, we mainly increase the adhesion of PMMA substrate and film, which is reflected in the environmental test. This study used plasma-enhanced atomic layer deposition (PEALD) to find the relationship between the intensity of XRD reflection peak and the root-mean-square surface roughness (σRMS) of hafnium dioxide (HfO2) at different thicknesses by reducing the plasma power at different process temperatures. In this experiment, HfO2 was found to have the highest intensity of XRD at its maximum thickness. According to the different intensities of XRD of HfO2 at different thicknesses, aluminum oxide (Al2O3) was inserted as crystallization cutoff layers, and the two materials were combined into nanolaminates. The corresponding σRMS value also changed from 1.25 to 0.434 nm after treatment under the fourth experimental design. This study improved this mismatch between interfaces by adjusting the yield strength and ductility using Al2O3 layers and by creating an inhibition layer. In addition, through the processing of inserted Al2O3 layers, the degree of crystallization was changed so that the material and substrate could maintain their normal surfaces without cracking after the environmental tests. After inserting five 1 nm thick Al2O3 layers, the environmental test results were improved. The test time was increased from the original 56 h to 352 h. Full article
(This article belongs to the Section Innovations in Materials Processing)
18 pages, 2122 KiB  
Article
Children’s Perceived Ease of Use of a Projected Augmented Reality Game Designed for Balance and Coordination Training
by Yishi Liu, Leigh Achterbosch, Grant Meredith, Evan Dekker, Suryani Lim and Andrew P. Lavender
Technologies 2025, 13(1), 9; https://doi.org/10.3390/technologies13010009 - 27 Dec 2024
Viewed by 410
Abstract
Developing balance and coordination skills is essential for children, especially those aged 4–8, but limited Health and Physical Education (HPE) programs in schools hinder effective training. Game-based learning and Augmented Reality (AR) technologies offer promising ways to enhance these skills by providing immersive [...] Read more.
Developing balance and coordination skills is essential for children, especially those aged 4–8, but limited Health and Physical Education (HPE) programs in schools hinder effective training. Game-based learning and Augmented Reality (AR) technologies offer promising ways to enhance these skills by providing immersive HPE experiences. An AR exercise-game prototype was developed to train children’s balance and coordination, with 19 children aged 4 to 9 testing the prototype. Post-activity surveys revealed high engagement and interactivity ratings. The difficultly of the current prototype was found to be appropriately challenging for 4- to 6-year-olds. Feedback emphasized a preference for interactive, challenging elements, suggesting improvements in difficulty customization, visuals, and technical stability. Competitive play between multiple children testing the prototype encouraged repeated attempts, but also highlighted the need for improved tracking solutions and lab setup. Overall, the innovative design shows educational potential but requires further large-scale testing on a refined version to assess its effectiveness in balance and coordination training. Full article
(This article belongs to the Section Assistive Technologies)
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<p>Conceptual mock-up of the exergame. Icons are projected on the wall and they fly in at random heights from left or right of the wall.</p>
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<p>(<b>a</b>) Initial concept art for AR Exergame prototype; (<b>b</b>) Intel Realsense D435 Depth camera tracking each joint during the actual testing of the prototype game.</p>
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<p>TAM Model adapted from Davis (1985).</p>
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<p>Smileyometer to help children choose a score.</p>
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<p>Embedded Sequential Design.</p>
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<p>Boxplots representing the results of survey questions 1 to 6.</p>
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19 pages, 13592 KiB  
Article
Firefighting with Conductive Aerosol-Assisted Vortex Rings
by John LaRocco, Qudsia Tahmina, Stanley Essel and John Simonis
Technologies 2025, 13(1), 10; https://doi.org/10.3390/technologies13010010 - 27 Dec 2024
Viewed by 306
Abstract
Conventional firefighting tools and methods can strain water sources, require toxic foams, or rely on pre-installed countermeasures. A low-cost, non-toxic, and portable option was previously overlooked in portable devices: electrically assisted “ionic wind” fire suppression. Conductive aerosols, carried by vortex rings, can potentially [...] Read more.
Conventional firefighting tools and methods can strain water sources, require toxic foams, or rely on pre-installed countermeasures. A low-cost, non-toxic, and portable option was previously overlooked in portable devices: electrically assisted “ionic wind” fire suppression. Conductive aerosols, carried by vortex rings, can potentially extend the length of an electric arc and suppress fires. After the simulation, two prototype vortex ring launchers were compared, one using compressed air and another using an elastic diaphragm. The efficiency of each test case was assessed with a purpose-built automated image analysis system. The compressed air vortex launcher had a significantly higher efficiency than the elastic diaphragm prototype, with a p-value of 0.0006. Regardless of the prototype or the use of conductive aerosols, the device had an effective range of up to 1.98 m. The highest reliability of 90 ± 4.1% was achieved at 1.52 m from the launcher. The observations with compressed air launcher results saw no significant difference regarding the use of the conductive aerosol. Further investigation of the concept requires a systematic examination of other types of fires, electronic optimization, permutations of chemicals and concentrations, other types of vortex generation, and human factors. The computer vision system could also be used to further detect and target active fires. Beyond firefighting, the device can be adapted to applications ranging from manufacturing to aerospace. Regardless of the use of conductive aerosols, handheld vortex ring generators are a versatile, potential firefighting tool. Full article
(This article belongs to the Section Environmental Technology)
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<p>Iterative process for conductive aerosol testing.</p>
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<p>Aerosol emission and mounting on prototypes.</p>
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<p>Illustration of 2D simulation of vortex ring generator muzzle shapes. (<b>A</b>) Conical muzzle launcher and (<b>B</b>) square-edged muzzle launcher.</p>
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<p>Illustration of 3D simulation of vortex ring formation.</p>
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<p>Operation of experimental vortex ring launcher.</p>
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<p>(<b>A</b>) Angled view of the vortex launcher, with 11 cm front hole diameter and mounted components denoted. (<b>B</b>) Sideways view of the launcher, with device dimensions and battery denoted.</p>
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<p>Candle grid for vortex ring testing.</p>
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<p>Observed distances of aerosol-augmented electric arcs.</p>
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<p>Comparative results of vortex launchers and conductive aerosol.</p>
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<p>Heatmap of the 1.52 m (5 ft)-distance test with the first prototype with conductive aerosols (Case 1).</p>
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<p>Heatmap of the 1.52 m (5 ft)-distance test with the first prototype without conductive aerosols (Case 2).</p>
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<p>Heatmap of the 1.52 m (5 ft)-distance test with the second prototype with conductive aerosols (Case 3).</p>
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<p>Heatmap of the 1.52 m (5 ft)-distance test with the second prototype without conductive aerosols (Case 4).</p>
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<p>Heatmap of the 2.13 m (7 ft)-distance test with the first prototype with conductive aerosols (Case 1).</p>
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<p>Heatmap of the 2.13 m (7 ft)-distance test with the first prototype without conductive aerosols (Case 2).</p>
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<p>Heatmap of the 2.13 m (7 ft)-distance test with the second prototype with conductive aerosols (Case 3).</p>
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<p>Heatmap of the 2.13 m (7 ft)-distance test with the second prototype without conductive aerosols (Case 4).</p>
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<p>Comparative efficiency and average performance of Cases 1–4 at 1.52 m and 2.13 m.</p>
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17 pages, 511 KiB  
Article
Enhancing Security in International Data Spaces: A STRIDE Framework Approach
by Nikola Gavric, Andrii Shalaginov, Aliaksei Andrushevich, Andreas Rumsch and Andrew Paice
Technologies 2025, 13(1), 8; https://doi.org/10.3390/technologies13010008 - 26 Dec 2024
Viewed by 293
Abstract
The proliferation of Internet of Things (IoT) devices and big data has catalyzed the emergence of data markets. Regulatory and technological frameworks such as International Data Spaces (IDS) have been developed to facilitate secure data exchange while integrating security and data sovereignty aspects [...] Read more.
The proliferation of Internet of Things (IoT) devices and big data has catalyzed the emergence of data markets. Regulatory and technological frameworks such as International Data Spaces (IDS) have been developed to facilitate secure data exchange while integrating security and data sovereignty aspects required by laws and regulations, such as the GDPR and NIS2. Recently, novel attack vectors have taken a toll on many enterprises, causing significant damage despite the deployed security mechanisms. Hence, it is reasonable to assume that the IDS may be just as susceptible. In this paper, we conduct a STRIDE threat analysis on IDS to assess its susceptibility to traditional and emerging cybersecurity threats. Specifically, we evaluate novel threats such as Man-in-the-Middle (MitM) attacks, compromised end-user devices, SIM swapping, and potential backdoors in commonly used open-source software. Our analysis identifies multiple vulnerabilities, particularly at the trust boundary (TB) between users and the IDS system. These include the traditionally troublesome Denial of Service (DoS) attacks, key management weaknesses, and the mentioned novel threats. We discuss the hacking techniques, tools, and associated risks to the IDS framework, followed by targeted mitigation strategies and recommendations. This paper provides a framework for performing a STRIDE-based threat analysis of the IDS. Using the proposed methodology, we identified the most potent threats and suggested solutions, thus contributing to the development of a safer and more resilient data space architecture. Full article
(This article belongs to the Section Information and Communication Technologies)
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<p>The IDS context diagram.</p>
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<p>Attack tree for spoofing at TB 2.</p>
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31 pages, 7637 KiB  
Article
Enhancing Early Breast Cancer Detection with Infrared Thermography: A Comparative Evaluation of Deep Learning and Machine Learning Models
by Reem Jalloul, Chethan Hasigala Krishnappa, Victor Ikechukwu Agughasi and Ramez Alkhatib
Technologies 2025, 13(1), 7; https://doi.org/10.3390/technologies13010007 - 26 Dec 2024
Viewed by 308
Abstract
Breast cancer remains one of the most prevalent and deadly cancers affecting women worldwide. Early detection is crucial, particularly for younger women, as traditional screening methods like mammography often struggle with accuracy in cases of dense breast tissue. Infrared thermography offers a non-invasive [...] Read more.
Breast cancer remains one of the most prevalent and deadly cancers affecting women worldwide. Early detection is crucial, particularly for younger women, as traditional screening methods like mammography often struggle with accuracy in cases of dense breast tissue. Infrared thermography offers a non-invasive imaging alternative that enhances early detection by capturing subtle thermal variations indicative of breast abnormalities. This study investigates and compares the performance of various deep learning and machine learning models in analyzing thermographic data to classify breast tissue as healthy, benign, or malignant. To maximize detection accuracy, data preprocessing, feature extraction, and dimensionality reduction were implemented to isolate distinguishing characteristics across tissue types. Leveraging advanced feature extraction and visualization techniques inspired by geospatial data methodologies, we evaluated several deep learning architectures and classical classifiers using the DRM-IR and Breast Thermography Mendeley thermal datasets. Among the tested models, the ResNet152 architecture combined with a Support Vector Machine (SVM) classifier delivered the highest performance, achieving 97.62% accuracy, 95.79% precision, 98.53% recall, 94.52% specificity, an F1 score of 97.16%, an area under the curve (AUC) of 99%, a latency of 0.06 s, and CPU utilization of 88.66%. These findings underscore the potential of integrating infrared thermography with advanced deep learning and machine learning approaches to significantly improve the accuracy and efficiency of breast cancer detection, supporting its role as a valuable tool for early diagnosis. Full article
(This article belongs to the Section Information and Communication Technologies)
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<p>Proposed Framework for Feature Extraction and Classification from Thermal Breast Images.</p>
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<p>Sample of Thermal Images from Dataset.</p>
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<p>Example of a Full-Body Thermal Image Capturing the Breast Area.</p>
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<p>Effects of the preprocessing filters applied to infrared images.</p>
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<p>Distribution of pixel intensities on the real-world vs. augmented data.</p>
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<p>Workflow of 10-fold cross-validation implementation.</p>
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<p>PCA Visualization of Thermal Image Features for Breast Cancer Detection.</p>
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<p>Feature Correlation Heatmap for Thermal Image Dataset.</p>
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<p>Top 10 Most Important Features from the Thermal Images for Breast Cancer Detection.</p>
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<p>Confusion Matrix for SVM with ResNet-152 Features.</p>
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<p>Precision–Recall Curve of the Model.</p>
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<p>The ROC curve of the Model.</p>
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<p>Accuracy Comparison of Classifiers across Feature Models.</p>
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<p>AUC Comparison of Classifiers across Feature Models for Breast Cancer Classification.</p>
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<p>Grad-CAM Overlay for Normal Class (the original thermal image (<b>left</b>) alongside the Grad-CAM overlay (<b>right</b>) highlights the regions contributing to the model’s prediction of the “Normal” class with a confidence score of 0.80).</p>
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<p>Grad-CAM Overlay for Sick Class (the original thermal image (<b>left</b>) alongside the Grad-CAM overlay (<b>right</b>) demonstrates the model’s focus on specific regions, leading to the prediction of the “Sick” class with a confidence score of 0.85).</p>
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<p>Grad-CAM Overlay for Malignant Class (the original thermal image (<b>left</b>) and its corresponding Grad-CAM overlay (<b>right</b>) show the model’s focus on abnormal heat regions, supporting the “malignant” classification with a confidence score of 0.89).</p>
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<p>Grad-CAM Overlay for Benign Class (the original thermal image (<b>left</b>) and its Grad-CAM overlay (<b>right</b>) depict the regions contributing to the model’s prediction of the “benign” class with a confidence score of 0.88).</p>
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<p>(<b>Left</b>) Original thermal image highlighting the temperature distribution across the chest area, with warmer regions indicated by red/yellow hues and cooler regions by blue/green hues. (<b>Right</b>) Grad-CAM overlay demonstrating the areas of highest model attention during classification, with cooler colours indicating less attention and warmer colours indicating regions of interest.</p>
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21 pages, 2294 KiB  
Review
Control Strategies for Steer-By-Wire Systems: An Overview
by Muhammad Arjuna Putra Perdana, Alexander C. Budiman, Rina Ristiana, Aam Muharam, Kristian Ismail, Muhammad Redho Kurnia, Amin, Naili Huda, Sunarto Kaleg and Abdul Hapid
Technologies 2025, 13(1), 6; https://doi.org/10.3390/technologies13010006 - 25 Dec 2024
Viewed by 265
Abstract
Steer-by-wire (SbW) is the latest steering evolution, providing many benefits, such as reduced vehicle weight and enhanced steering capability. While reliability is one of the main concerns hindering its widespread application, the potential of this technology to revolutionize the automotive industry is huge. [...] Read more.
Steer-by-wire (SbW) is the latest steering evolution, providing many benefits, such as reduced vehicle weight and enhanced steering capability. While reliability is one of the main concerns hindering its widespread application, the potential of this technology to revolutionize the automotive industry is huge. Control techniques play an important part in achieving the full potential of SbW by focusing on the development of its performance and safety aspects. This paper provides a review of the control techniques that are being used in SbW technology to achieve better performance and enhance safety. Various control techniques for SbW exist to serve different purposes when dealing with the non-linear nature of the SbW dynamics. Although there is no one-size-fits-all control technique for all the requirements of the SbW, this study highlights that the non-linear controllers based on the sliding mode control (SMC) are a popular option for enhancing the accuracy of SbW systems. However, these controllers often suffer from a downside known as chattering. In contrast, robust controllers like Model Predictive Controllers (MPCs) can effectively manage uncertain dynamics and eliminate chattering, although they pose challenges due to their high computational costs. Full article
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<p>Evolution of steering technology.</p>
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<p>Typical layout of the SbW.</p>
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<p>Two-degree-of-freedom model of SbW.</p>
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<p>The main objective of control in SbW.</p>
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<p>Typical classical PID control diagram in SbW.</p>
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<p>Typical sliding mode control diagram in SbW.</p>
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19 pages, 5764 KiB  
Article
A Cross-Shaped Slotted Patch Sensor Antenna for Ice and Frost Detection
by Rula Alrawashdeh
Technologies 2025, 13(1), 5; https://doi.org/10.3390/technologies13010005 - 25 Dec 2024
Viewed by 269
Abstract
Beyond data transmission, antennas have recently been utilized as sensors, offering the advantage of reducing hardware requirements and power consumption compared to systems where sensors are separate from antennas. Patch antennas, in particular, are widely used across various applications, including sensing, due to [...] Read more.
Beyond data transmission, antennas have recently been utilized as sensors, offering the advantage of reducing hardware requirements and power consumption compared to systems where sensors are separate from antennas. Patch antennas, in particular, are widely used across various applications, including sensing, due to their attractive features like compact size and conformability. In addition, they can be easily designed in different ways to sense variations in certain variables. Adding a slot to the patch antenna introduces several advantages, including multiband, wideband operation, and improved impedance bandwidth. Slots also provide a concentrated region of electromagnetic fields, which increases the antenna’s sensitivity for sensing and detection purposes. In this paper, a rectangular patch antenna with a cross slot is designed and proposed for water, ice, and frost detection. Detection is achieved by measuring variations in the resonant frequency in response to water, ice accumulation, and frost. The results indicate that the proposed antenna can detect both water and ice accretion with a frequency shift of up to 1.538, 0.358, and 0.056 GHz, respectively, which reflects good sensitivity levels of the antenna. The effect of the slot on strengthening the near electric field and antenna sensitivity is discussed in this paper. The antenna is fabricated and measured and the indicators of each detection scale have been extracted. The proposed antenna has a simple structure and a small size of (40 × 40 × 1.53 m3). In addition, it can be precisely used to sense different environmental parameters such as frost and ice. Thus, it can serve as a strong candidate for detecting natural disasters like frost damage. Furthermore, the findings in this paper offer valuable insights into how the presence and structure of slots influence the sensitivity response of patch antennas, supporting ongoing research in this field. Full article
(This article belongs to the Section Information and Communication Technologies)
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<p>A block diagram of a wireless detection system based on antennas.</p>
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<p>The proposed antenna design: (<b>a</b>) typical patch without a slot, (<b>b</b>) with a cross-shaped slot; L<sub>G</sub> = 40, W<sub>G</sub> = 40, L = 21, W = 30.5, L<sub>m</sub> = 15, W<sub>m</sub> = 3, L<sub>S</sub> = 15, W<sub>S</sub> = 4, S<sub>1</sub> = 3, S<sub>2</sub> = 4, S<sub>3</sub> = 7; dimensions in mm.</p>
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<p>The −10 dB reflection coefficient of the proposed cross-slotted patch antenna in comparison with the corresponding typical rectangular patch antenna.</p>
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<p>The antenna with a (<b>a</b>) full layer of water, ice, or frost and (<b>b</b>) partial layer of water, ice, or frost on the slot only; loading layers are presented in blue.</p>
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<p>The reflection coefficient (S<sub>11</sub>) of the simulated antenna with a 1 mm layer of water and ice on its top.</p>
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<p>The reflection coefficient (S<sub>11</sub>) of full and partial layers of water and ice on the antenna top.</p>
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<p>The reflection coefficient (S<sub>11</sub>) of the three frost layers (ɛ<sub>r</sub> = 1.5 (F1), 2 (F2), 2.5 (F3), and σ = 1 × 10<sup>−5</sup> S/m) covering the entire patch surface.</p>
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<p>The reflection coefficient (S<sub>11</sub>) of the three frost layers (ɛ<sub>r</sub> = 1.5 (F1), 2 (F2), 2.5 (F3), and σ = 1 × 10<sup>−5</sup> S/m) covering the slot only.</p>
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<p>The near electric field of the antenna: (<b>a</b>) without the slot and (<b>b</b>) with the slot. The top and bottom arrows indicate the maximum and minimum visualized magnitudes of the near electric field, respectively.</p>
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<p>The reflection coefficient (S<sub>11</sub>) of different ice layers of 2, 3, 4, and 5 mm thicknesses.</p>
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<p>The fabricated cross-shaped slot antenna.</p>
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<p>The fabricated cross-shaped slot antenna loaded with (<b>a</b>) water and (<b>b</b>) ice.</p>
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<p>The measured results compared to simulated ones of the reflection coefficient (S<sub>11</sub>) for the antenna without loading and with water covering the overall antenna top (full) and the slot only (part).</p>
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<p>The measured results compared to simulated ones of the reflection coefficient (S<sub>11</sub>) for the antenna with a layer of ice covering the overall antenna top and the slot only.</p>
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<p>The measured results of the reflection coefficient (S<sub>11</sub>) for the antenna for four samples starting with an ice layer taken every 1.5 min.</p>
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<p>The radiation pattern at 5.6 GHz for the antenna: (<b>a</b>) without loading and (<b>b</b>) loaded with water and ice.</p>
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<p>The 3D directivity pattern for the antenna: (<b>a</b>) without the slot and (<b>b</b>) with the slot. The top and bottom arrows indicate the maximum and minimum visualized magnitudes of the directivity, respectively.</p>
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31 pages, 3605 KiB  
Article
Intelligent IoT-Based Network Clustering and Camera Distribution Algorithm Using Reinforcement Learning
by Islam T. Almalkawi, Rami Halloush, Mohammad F. Al-Hammouri, Alaa Alghazo, Loiy Al-Abed, Mohammad Amra, Ayooub Alsarhan and Sami Aziz Alshammari
Technologies 2025, 13(1), 4; https://doi.org/10.3390/technologies13010004 - 24 Dec 2024
Viewed by 332
Abstract
The advent of a wide variety of affordable communication devices and cameras has enabled IoT systems to provide effective solutions for a wide range of civil and military applications. One of the potential applications is a surveillance system in which several cameras collaborate [...] Read more.
The advent of a wide variety of affordable communication devices and cameras has enabled IoT systems to provide effective solutions for a wide range of civil and military applications. One of the potential applications is a surveillance system in which several cameras collaborate to monitor a specific area. However, existing surveillance systems are often based on traditional camera distribution and come with additional communication costs and redundancy in the detection range. Thus, we propose a smart and efficient camera distribution system based on machine learning using two Reinforcement Learning (RL) methods: Q-Learning and neural networks. Our proposed approach initially uses a geometric distributed network clustering algorithm that optimizes camera placement based on the camera Field of View (FoV). Then, to improve the camera distribution system, we integrate it with an RL technique, the role of which is to dynamically adjust the previous/existing setup to maximize target coverage while minimizing the number of cameras. The reinforcement agent modifies system parameters—such as the overlap distance between adjacent cameras, the camera FoV, and the number of deployed cameras—based on changing traffic distribution and conditions in the surveilled area. Simulation results confirm that the proposed camera distribution algorithm outperforms the existing methods when comparing the required number of cameras, network coverage percentage, and traffic coverage. Full article
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<p>Illustration of camera FoV.</p>
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<p>Workflow of reinforcement learning.</p>
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<p>The Turtlebot2 robot platform.</p>
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<p>Map of our lab area generated by Turtlebot2.</p>
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<p>Detection and tracking.</p>
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<p>Reinforcement agent function.</p>
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<p>Reinforcement agent’s decision.</p>
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<p>Workflow of our reinforcement agent.</p>
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<p>DQN approach.</p>
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<p>Workflow of our proposed solution.</p>
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<p>Non-overlapping camera distribution scenario.</p>
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<p>Overlapping camera distribution scenario.</p>
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<p>Overlapped scenario plot: added cameras in opposite direction.</p>
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<p>Reinforcement agent performance with window size (100).</p>
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<p>DQN RL agent total reward.</p>
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<p>DQN RL agent loss function.</p>
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<p>Coverage area vs. number of cameras.</p>
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<p>Coverage area vs. terrain.</p>
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<p>Coverage ratio vs. number of targets.</p>
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<p>Fairness index vs. number of cameras.</p>
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31 pages, 6319 KiB  
Article
A Survey of Efficient Lightweight Cryptography for Power-Constrained Microcontrollers
by Jesús Soto-Cruz, Erica Ruiz-Ibarra, Javier Vázquez-Castillo, Adolfo Espinoza-Ruiz, Alejandro Castillo-Atoche and Joaquin Mass-Sanchez
Technologies 2025, 13(1), 3; https://doi.org/10.3390/technologies13010003 - 24 Dec 2024
Viewed by 404
Abstract
Protecting sensitive data, such as data collected from sensors, is crucial for ensuring the accurate assessment of sensing devices and preventing unauthorized access. In this regard, Internet of Things (IoT) devices offer a promising alternative for in situ monitoring. However, IoT sensing devices [...] Read more.
Protecting sensitive data, such as data collected from sensors, is crucial for ensuring the accurate assessment of sensing devices and preventing unauthorized access. In this regard, Internet of Things (IoT) devices offer a promising alternative for in situ monitoring. However, IoT sensing devices are often constrained by limited processing power and memory. Therefore, lightweight and efficient security algorithms are essential. This review paper assesses the implementation of lightweight cryptographic algorithms for power-constrained microcontrollers in IoT systems using symmetric cryptography. The implemented algorithms analyze the resource constraints of the IoT devices and compare their performance for the efficient implementation of secure monitoring systems. Experimental results demonstrate the performance of various lightweight encryption algorithms on low-power microcontrollers. The analysis reveals the comparative performance of these algorithms in terms of average power and energy consumption, memory usage, latency, and throughput. Full article
(This article belongs to the Topic Emerging Technologies, Law and Policies)
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<p>Security mechanisms used in IoT.</p>
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<p>Symmetric encryption process diagram.</p>
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<p>Encryption and decryption process using a block cipher algorithm.</p>
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<p>Encryption and decryption process using a stream cipher algorithm.</p>
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<p>Flowchart of the work methodology used in this research.</p>
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<p><math display="inline"><semantics> <mrow> <mi>e</mi> <mi>x</mi> <mi>e</mi> <mi>c</mi> <mi>u</mi> <mi>t</mi> <mi>i</mi> <mi>o</mi> <mi>n</mi> <mi>T</mi> <mi>i</mi> <mi>m</mi> <mi>e</mi> </mrow> </semantics></math> determination process.</p>
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<p>Electrical circuit used to measure current in the development boards.</p>
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<p>Communication between the development board and computer to visualize results.</p>
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<p>Memory usage per algorithm. (<b>a</b>) RAM memory; (<b>b</b>) ROM/FLASH memory.</p>
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<p>Encryption/Decryption latency per algorithm on the ESP32 board.</p>
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<p>Encryption/Decryption latency per algorithm on the ESP8266 board.</p>
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<p>Encryption/Decryption latency per algorithm on the MSP430 Launchpad board.</p>
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<p>Encryption/Decryption latency per algorithm on the NUCLEO-G0B1RE board.</p>
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<p>Encryption/Decryption latency per algorithm on the Arduino Nano board [µs/B].</p>
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<p>Encryption/Decryption throughput per algorithm on the ESP32 board.</p>
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<p>Encryption/Decryption throughput per algorithm on the ESP8266 board.</p>
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<p>Encryption/Decryption throughput per algorithm on the MSP430 Launchpad board.</p>
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<p>Encryption/Decryption throughput per algorithm on the NUCLEO-G0B1RE board.</p>
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<p>Encryption/Decryption throughput per algorithm on the Arduino Nano board.</p>
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<p>Average current usage per algorithm. (<b>a</b>) Encryption current usage; (<b>b</b>) decryption current usage.</p>
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<p>Electric power rate per algorithm. (<b>a</b>) Encryption power rate; (<b>b</b>) decryption power rate.</p>
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<p>Energy required to encrypt/decrypt one byte of data per algorithm on the ESP32 board.</p>
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<p>Energy required to encrypt/decrypt one byte of data per algorithm on the ESP8266 board.</p>
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<p>Energy required to encrypt/decrypt one byte of data per algorithm on the MSP430 Launchpad board.</p>
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<p>Energy required to encrypt/decrypt one byte of data per algorithm on the NUCLEO-G0B1RE board.</p>
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<p>Energy required to encrypt/decrypt one byte of data per algorithm on the Arduino Nano board [µJ/B].</p>
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<p>Resource usage vs throughput matrix.</p>
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23 pages, 3175 KiB  
Article
Assisting Hearing and Physically Impaired Students in Navigating Immersive Virtual Reality for Library Orientation
by Pakinee Ariya, Yakannut Yensathit, Phimphakan Thongthip, Kannikar Intawong and Kitti Puritat
Technologies 2025, 13(1), 2; https://doi.org/10.3390/technologies13010002 - 24 Dec 2024
Viewed by 362
Abstract
This study aims to design and develop a virtual reality platform (VR-ISLS) tailored to support hearing and physically impaired students at the university library for navigating and utilizing library services. By employing an immersive virtual environment, the platform replicates the physical setting of [...] Read more.
This study aims to design and develop a virtual reality platform (VR-ISLS) tailored to support hearing and physically impaired students at the university library for navigating and utilizing library services. By employing an immersive virtual environment, the platform replicates the physical setting of the university’s library to create a realistic experience that reduces anxiety and enhances familiarity. The platform integrates assistive technology functions, including sign language interpretation, customizable audio cues, vibration feedback, and various locomotion controls to meet the diverse needs of impaired students. The research methodology employs an iterative development process, incorporating feedback from library staff, disability support services, and students to ensure usability and accessibility. Evaluation of the platform using the System Usability Scale (SUS) and user feedback revealed a positive reception, with recommendations for further customization and enhanced assistive features to optimize the user experience. This study underscores the importance of inclusive design and continuous iteration in creating immersive virtual reality tools that provide significant benefits for persons with disabilities, enhancing both accessibility and learning experiences. Full article
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<p>The overall process of implementing the VR application.</p>
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<p>The blueprint of the first floor and physical environment of the library for hearing and physically impaired students.</p>
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<p>The 3D environment of the library and points of interest for user participation.</p>
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<p>Examples of user interfaces (<b>left</b>) and the design of a user interface for impaired students (<b>right</b>).</p>
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<p>Example of locomotion with the gamepad (<b>left</b>) and locomotion with teleportation (<b>right</b>).</p>
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<p>Example of a hybrid method (combining gamepad and head tracking) for students with upper limb amputations.</p>
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<p>The result of the SUS score for the VR platform.</p>
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<p>The result of satisfaction questionnaire.</p>
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20 pages, 7543 KiB  
Article
ChatBlock: A Block-Based Chatbot Framework for Supporting Young Learners and the Classroom Authoring for Teachers
by Chutiporn Anutariya, Hathaichanok Chawmungkrung, Watanee Jearanaiwongkul and Teeradaj Racharak
Technologies 2025, 13(1), 1; https://doi.org/10.3390/technologies13010001 - 24 Dec 2024
Viewed by 357
Abstract
Chatbots have been used as a digital interactive learning tool in education. Designing a chatbot for young students has challenges in their capability to formulate sentences by typing. Teachers have a challenge to develop a chatbot for desired purposes as well as to [...] Read more.
Chatbots have been used as a digital interactive learning tool in education. Designing a chatbot for young students has challenges in their capability to formulate sentences by typing. Teachers have a challenge to develop a chatbot for desired purposes as well as to suit their classes. This research proposes a ChatBlock framework that provides ChatBlock Tutor and ChatBlock Classroom interfaces to serve the target users. ChatBlock Tutor is designed as a block-based interface to support young students to connect various types of blocks for creating sentences. The formulated block-based sentences are used to make a conversation with the chatbot. On the other hand, the ChatBlock Classroom is developed to support teachers in preparing customizable content for a classroom in various formats, i.e., Q&As, learning materials, exercises, and quizzes. Finally, the design and development of ChatBlock is discussed and two case studies in primary schools are elaborated. We conduct a preliminary evaluation with a selected primary school and report the lessons learned from our study. Full article
(This article belongs to the Section Information and Communication Technologies)
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<p>ChatBlock’s system.</p>
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<p>Our conceptual design of knowledge’ structure used in ChatBlock.</p>
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<p>Block-based language design.</p>
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<p>The UI of ChatBlock Tutor.</p>
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<p>The UI of ChatBlock Classroom.</p>
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<p>A student learns and asks questions though ScienceChat.</p>
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<p>A student selects a lesson block to learn about Natural Phenomena.</p>
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<p>A student takes a quiz and obtains the results.</p>
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<p>The use of ScratchChat to learn about the motion block category in Scratch.</p>
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<p>A student requests an exercise from ScratchChat.</p>
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