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22 pages, 10279 KiB  
Article
Cybersecurity Challenges in UAV Systems: IEMI Attacks Targeting Inertial Measurement Units
by Issam Boukabou, Naima Kaabouch and Dulana Rupanetti
Drones 2024, 8(12), 738; https://doi.org/10.3390/drones8120738 - 8 Dec 2024
Viewed by 753
Abstract
The rapid expansion in unmanned aerial vehicles (UAVs) across various sectors, such as surveillance, agriculture, disaster management, and infrastructure inspection, highlights the growing need for robust navigation systems. However, this growth also exposes critical vulnerabilities, particularly in UAV package delivery operations, where intentional [...] Read more.
The rapid expansion in unmanned aerial vehicles (UAVs) across various sectors, such as surveillance, agriculture, disaster management, and infrastructure inspection, highlights the growing need for robust navigation systems. However, this growth also exposes critical vulnerabilities, particularly in UAV package delivery operations, where intentional electromagnetic interference (IEMI) poses significant security and safety threats. This paper addresses IEMI attacks targeting inertial measurement units (IMUs) in UAVs, focusing on their susceptibility to medium-power electromagnetic interference. Our approach combines a comprehensive literature review and QuickField simulation with experimental validation using a commercially available 6-degree-of-freedom (DOF) IMU sensor. We propose a hardware-based electromagnetic shielding solution using mu-metal to mitigate IEMI’s impact on sensor performance. The study combines experimental testing with simulations to evaluate the shielding effectiveness under controlled conditions. The results of the measurements showed that medium-power IEMI significantly distorted IMU sensor readings, but our proposed shielding method effectively reduces the impact, improving sensor reliability. We demonstrate the mechanisms by which medium-power IEMI disrupts sensor operation, offering insights for future research directions. These findings also highlight the importance of integrating hardware-based shielding solutions to safeguard UAV systems against electromagnetic threats. Full article
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<p>(<b>a</b>) 6-DOF IMU sensor package; (<b>b</b>) orientation of axes of sensitivity and polarity of rotation [<a href="#B20-drones-08-00738" class="html-bibr">20</a>].</p>
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<p>Reference model of an accelerometer.</p>
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<p>Reference model of a gyroscope.</p>
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<p>Magnetic shielding demonstration: (<b>a</b>) magnetic flux interacting with unshielded assets; (<b>b</b>) magnetic flux redirected and absorbed by a mu-metal protective shield.</p>
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<p>Custom-built EMF antenna.</p>
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<p>Experiment setup: (<b>a</b>) IMU and EMF antenna mounted on a stable platform; (<b>b</b>) IMU sensor connected to Arduino over Qwiic.</p>
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<p>Initial tests 1 and 2: (<b>a</b>) acceleration vs. time; (<b>b</b>) angular velocity vs. time for a stationary IMU under normal conditions.</p>
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<p>Initial tests 1 and 2: (<b>a</b>) accelerometer percentage error; (<b>b</b>) gyroscope percentage error.</p>
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<p>(<b>a</b>) Accelerometer readings before and after the IEMI attack; (<b>b</b>) accelerometer percentage error.</p>
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<p>(<b>a</b>) Rotational velocity readings before and after the IEMI attack; (<b>b</b>) rotational velocity percentage error.</p>
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<p>(<b>a</b>) Accelerometer readings before and after the IEMI attack; (<b>b</b>) rotational velocity readings before and after the IEMI attack.</p>
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<p>(<b>a</b>) Accelerometer readings before and after the IEMI attack; (<b>b</b>) accelerometer percentage error.</p>
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<p>(<b>a</b>) Rotational velocity readings before and after the IEMI attack; (<b>b</b>) rotational velocity percentage error.</p>
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<p>MPU−6050’s block diagram [<a href="#B20-drones-08-00738" class="html-bibr">20</a>].</p>
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<p>Magnetic field strength distribution: (<b>a</b>) around the mu-metal shield in a closed configuration; (<b>b</b>) with a side opening for wire accommodation.</p>
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<p>Shielding effect of magnetic field for different materials and foil layer configurations.</p>
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<p>Shielded IMU from the EMF antenna, demonstrating reduced interference with the proposed shield in place for: (<b>a</b>) accelerometer; (<b>b</b>) gyroscope.</p>
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28 pages, 15457 KiB  
Article
Intelligent Dynamic Trajectory Planning of UAVs: Addressing Unknown Environments and Intermittent Target Loss
by Zhengpeng Yang, Suyu Yan, Chao Ming and Xiaoming Wang
Drones 2024, 8(12), 721; https://doi.org/10.3390/drones8120721 - 29 Nov 2024
Viewed by 376
Abstract
Precise trajectory planning is crucial in terms of enabling unmanned aerial vehicles (UAVs) to execute interference avoidance and target capture actions in unknown environments and when facing intermittent target loss. To address the trajectory planning problem of UAVs in such conditions, this paper [...] Read more.
Precise trajectory planning is crucial in terms of enabling unmanned aerial vehicles (UAVs) to execute interference avoidance and target capture actions in unknown environments and when facing intermittent target loss. To address the trajectory planning problem of UAVs in such conditions, this paper proposes a UAV trajectory planning system that includes a predictor and a planner. Specifically, the system employs a bidirectional Temporal Convolutional Network (TCN) and Gated Recurrent Unit (GRU) network algorithm with an adaptive attention mechanism (BITCN-BIGRU-AAM) to train a model that incorporates the historical motion trajectory features of the target and motion intention the inferred by a Dynamic Bayesian Network (DBN). The resulting predictions of the maneuvering target are used as terminal inputs for the planner. An improved Radial Basis Function (RBF) network is utilized in combination with an offline–online trajectory planning method for real-time obstacle avoidance trajectory planning. Additionally, considering future practical applications, the predictor and planner adopt a parallel optimization and correction algorithm structure to ensure planning accuracy and computational efficiency. Simulation results indicate that the proposed method can accurately avoid dynamic interference and precisely capture the target during tasks involving dynamic interference in unknown environments and when facing intermittent target loss, while also meeting system computational capacity requirements. Full article
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<p>UAV online obstacle avoidance trajectory diagram under intermittent target loss conditions, where the lines of different colors represent the different trajectories real-time planned for the UAV.</p>
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<p>Schematic showing the characteristics of UAV dynamics.</p>
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<p>Schematic of principle of target maneuvering intention derivation.</p>
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<p>Schematic diagram of threat of ground radar, where the asterisk (R) in the figure represents the ground radar station.</p>
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<p>The residual block schematic of TCN.</p>
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<p>The prediction algorithm structure of BITCN-BIGRU-AAM.</p>
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<p>A model diagram of general neurons.</p>
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<p>Obstacle avoidance trajectory planning based on RBF networks combined with offline–online alteration.</p>
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<p>The parallel system structure based on the BITCN-BIGRU-AAM and improved RBF algorithm.</p>
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<p>Algorithm prediction results.</p>
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<p>The diagram of the comparison of the prediction effects of different prediction algorithms under the random motion of the target.</p>
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<p>The predictive performance index diagram of the algorithm, where the figure (<b>a</b>) represents performance indicators and figure (<b>b</b>) represents performance normalization results.</p>
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<p>Generation of sample library.</p>
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<p>Regression curve of the training process.</p>
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<p>Comparison of online prediction results.</p>
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<p>Comparison error of online prediction results.</p>
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<p>Online obstacle avoidance trajectory planning under the dynamic radius interference, where the black dotted line represents the radius of 150 m, the blue dotted line represents the radius of 200 m, and the red solid line represents the radius of 140 m.</p>
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<p>UAV state variables under the dynamic-static radius joint interference.</p>
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<p>Online obstacle avoidance trajectory planning under the dynamic position interference, where the black dotted line, blue dashed line and red solid line represent show the blind spot at positions ranging from (5000, 1200) to (6000, 1330) meters.</p>
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<p>UAV state variables under the dynamicstatic position joint interference.</p>
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<p>UAV state variables under the dynamicstatic position joint interference.</p>
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<p>Online obstacle avoidance trajectory planning under the target prediction position interference, where change from the blue solid line to the green dashed line, respectively, represents the target capture area from (8680, 1630) to (8680, 1690) meters.</p>
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<p>UAV state variables under the target prediction position interference.</p>
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<p>System performance index.</p>
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13 pages, 7328 KiB  
Article
Analysis of Shielding Performance in Double-Layered Enclosures with Integrated Absorbers
by Jong Hwa Kwon, Chang-Hee Hyoung and Hyun Ho Park
Electronics 2024, 13(22), 4345; https://doi.org/10.3390/electronics13224345 - 6 Nov 2024
Viewed by 497
Abstract
Generally, various technologies, including waveguide below cutoff (WBC), gasket sealing, and bonding, are employed in metallic enclosures to achieve the high electromagnetic shielding performance required for EMP protection and EMC countermeasures in shielding structures or facilities. While the shielding structure or facility is [...] Read more.
Generally, various technologies, including waveguide below cutoff (WBC), gasket sealing, and bonding, are employed in metallic enclosures to achieve the high electromagnetic shielding performance required for EMP protection and EMC countermeasures in shielding structures or facilities. While the shielding structure or facility is properly constructed and maintained according to design specifications, its electromagnetic shielding performance can remain at the required level, effectively protecting internal electrical and electronic equipment from external electromagnetic interference. However, unintended apertures often occur during the construction or maintenance of shielding facilities, compromising their shielding performance. Therefore, it is crucial to develop technologies that prevent shielding effectiveness degradation caused by both intentional and unintentional apertures. This paper proposes a structure incorporating a composite absorber (made of dielectric and magnetic absorber) within a double metal panel of enclosure featuring an aperture, aimed at maintaining and improving the facility’s shielding performance. The effectiveness of the proposed structure was validated through numerical simulation. Full article
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<p>Electromagnetic shielding mechanism of practical metallic enclosures with apertures [<a href="#B8-electronics-13-04345" class="html-bibr">8</a>,<a href="#B9-electronics-13-04345" class="html-bibr">9</a>,<a href="#B10-electronics-13-04345" class="html-bibr">10</a>].</p>
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<p>Structures of infinite conductive plane and enclosure with an aperture: (<b>a</b>) Aperture on infinite metallic plates; (<b>b</b>) Metallic enclosure with an aperture.</p>
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<p>Analysis results of shielding effectiveness for infinite plane and enclosure with aperture.</p>
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<p>Enclosure structure with apertures at different positions on inner and outer metal panel: (<b>a</b>) Dual-metal-panel enclosure without absorber; (<b>b</b>) Dual-metal-panel enclosure with absorber.</p>
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<p>Complex permittivity of magnetic absorber [<a href="#B7-electronics-13-04345" class="html-bibr">7</a>]: (<b>a</b>) FSA300; (<b>b</b>) FS170.</p>
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<p>Shielding property of the dual-metal-panel enclosure with dielectric absorber: (<b>a</b>) Effects of absorber type with thickness of <span class="html-italic">d</span> = 10 mm; (<b>b</b>) Effects of absorber thickness.</p>
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<p>Shielding effectiveness of the dual-metal-panel enclosure with magnetic absorber: (<b>a</b>) Effects of absorber type with thickness of <span class="html-italic">d</span> = 20 mm; (<b>b</b>) Effects of absorber thickness.</p>
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<p>Analysis results of the dual-metal-panel enclosure based on type of composite absorber with total thickness of 20 mm.</p>
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<p>Enclosure with varying distances between the apertures on the outer metal panel.</p>
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<p>Analysis results of dual-metal-panel enclosure due to varying distances between the apertures on the outer metal panel.</p>
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<p>Enclosure with varying distances between apertures on the outer and inner metal panels.</p>
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<p>Enclosure with varying distances between the apertures on the outer metal panel.</p>
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17 pages, 549 KiB  
Article
The Benefits of an Integral HAMMAM Experience Combining Hydrotherapy and Swedish Massage on Pain, Subjective Well-Being and Quality of Life in Women with Endometriosis-Related Chronic Pelvic Pain: A Randomized Controlled Trial
by Ángel Rodríguez-Ruiz, Camila Arcos-Azubel, Manuel Ruiz-Pérez, Francisco Manuel Peinado, Antonio Mundo-López, Ana Lara-Ramos, María del Mar Salinas-Asensio and Francisco Artacho-Cordón
Medicina 2024, 60(10), 1677; https://doi.org/10.3390/medicina60101677 - 13 Oct 2024
Viewed by 1497
Abstract
Background and Objectives: To evaluate the effectiveness of an integral HAMMAM experience, a 4-week therapeutic program that combined hydrotherapy and Swedish massage, applied in a multisensorial immersive environment, on pain, well-being and quality of life (QoL) in women with endometriosis-related chronic pelvic [...] Read more.
Background and Objectives: To evaluate the effectiveness of an integral HAMMAM experience, a 4-week therapeutic program that combined hydrotherapy and Swedish massage, applied in a multisensorial immersive environment, on pain, well-being and quality of life (QoL) in women with endometriosis-related chronic pelvic pain that is unresponsive to conventional treatment. Materials and Methods: This randomized controlled trial included 44 women with endometriosis. They were randomly allocated to either the ‘HAMMAM’ group (n = 21) or to a control group (n = 23). The primary outcome, pain intensity, was evaluated using numeric rating scales (NRSs). The secondary outcomes were pain interference, pain-related catastrophic thoughts, pressure pain thresholds (PPTs), subjective well-being, functional capacity and QoL, which were evaluated using the brief pain inventory (BPI), the pain catastrophizing scale (PCS), algometry, the subjective well-being scale-20 (EBS-20), the Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29) and the Endometriosis Health Profile-30 Questionnaire (EHP-30), respectively. The primary and secondary outcomes were measured at the baseline and after the intervention. The statistical (between-group analyses of covariance) and clinical effects were analyzed by the intention to treat. Results: The adherence rate was 100.0% and the mean (± standard deviation) satisfaction was 9.71 ± 0.46 out of 10. No remarkable health problems were reported during the trial. The ‘HAMMAM’ intervention improved dysmenorrhea and dyspareunia after the intervention with large and moderate effect sizes, respectively. Improvements in pain interference during sleep and PPTs in the pelvic region were also observed in women allocated to the ‘HAMMAM’ group. No effects were observed in catastrophizing thoughts, well-being nor QoL, except for the sleep subscale. Conclusions: A 4-week program of an integral ‘HAMMAM’ experience combining hydrotherapy and massage in a multisensorial immersive environment is a feasible and effective intervention to alleviate pain during menstruation and sexual intercourse as well as pain interference with sleep in women with endometriosis. Full article
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<p>The flow of participants in the trial.</p>
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12 pages, 260 KiB  
Article
Work Situation of Midwives in Spain: Perception of Autonomy and Intention to Leave the Profession: A Cross-Sectional Study
by Susana Iglesias-Casás, Rafael Vila-Candel, Desirée Mena-Tudela, Anna Martín-Arribas and Fátima Leon-Larios
Healthcare 2024, 12(19), 1994; https://doi.org/10.3390/healthcare12191994 - 6 Oct 2024
Viewed by 991
Abstract
Background: Developed countries report specific issues regarding the declining midwifery workforce, and their shortage could have serious consequences for women’s sexual and reproductive health. The aim was to understand the perception of autonomy among midwives working in Spain, as well as factors related [...] Read more.
Background: Developed countries report specific issues regarding the declining midwifery workforce, and their shortage could have serious consequences for women’s sexual and reproductive health. The aim was to understand the perception of autonomy among midwives working in Spain, as well as factors related to their intention to leave the profession and their work environment. Method: A descriptive and cross-sectional study using an online questionnaire. Population: midwives working in Spain in any field (clinical, research, teaching, or management). Results: A sample of 1060 midwives was obtained. Of these, 53.7% (n = 569) feel autonomous in their work, 92.4% (n = 978) perceive that their profession frequently suffers from external interference, 46.6% (n = 494) have experienced sexist behaviors at work, and 53% (n = 561) have considered leaving the profession in the last year. Midwives with less than 10 years of experience (57.7%), those aged 31–45 years (59.8%), those with temporary contracts (38.3%), and those working in hospital care (71.9%) show a higher rate of considering leaving the profession (p < 0.001). Conclusions: Considering the current midwifery workforce crisis in Spain, it seems urgent to improve the working conditions of midwives to ensure the continuity and quality of women’s sexual and reproductive healthcare. Full article
(This article belongs to the Special Issue Building the Continuum of Care for Pregnant Women and Young Families)
17 pages, 2192 KiB  
Article
Composite Ensemble Learning Framework for Passive Drone Radio Frequency Fingerprinting in Sixth-Generation Networks
by Muhammad Usama Zahid, Muhammad Danish Nisar, Adnan Fazil, Jihyoung Ryu and Maqsood Hussain Shah
Sensors 2024, 24(17), 5618; https://doi.org/10.3390/s24175618 - 29 Aug 2024
Viewed by 798
Abstract
The rapid evolution of drone technology has introduced unprecedented challenges in security, particularly concerning the threat of unconventional drone and swarm attacks. In order to deal with threats, drones need to be classified by intercepting their Radio Frequency (RF) signals. With the arrival [...] Read more.
The rapid evolution of drone technology has introduced unprecedented challenges in security, particularly concerning the threat of unconventional drone and swarm attacks. In order to deal with threats, drones need to be classified by intercepting their Radio Frequency (RF) signals. With the arrival of Sixth Generation (6G) networks, it is required to develop sophisticated methods to properly categorize drone signals in order to achieve optimal resource sharing, high-security levels, and mobility management. However, deep ensemble learning has not been investigated properly in the case of 6G. It is anticipated that it will incorporate drone-based BTS and cellular networks that, in one way or another, may be subjected to jamming, intentional interferences, or other dangers from unauthorized UAVs. Thus, this study is conducted based on Radio Frequency Fingerprinting (RFF) of drones identified to detect unauthorized ones so that proper actions can be taken to protect the network’s security and integrity. This paper proposes a novel method—a Composite Ensemble Learning (CEL)-based neural network—for drone signal classification. The proposed method integrates wavelet-based denoising and combines automatic and manual feature extraction techniques to foster feature diversity, robustness, and performance enhancement. Through extensive experiments conducted on open-source benchmark datasets of drones, our approach demonstrates superior classification accuracies compared to recent benchmark deep learning techniques across various Signal-to-Noise Ratios (SNRs). This novel approach holds promise for enhancing communication efficiency, security, and safety in 6G networks amidst the proliferation of drone-based applications. Full article
(This article belongs to the Section Communications)
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<p>Block diagram of the proposed drone classification method.</p>
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<p>Signal samples before and after denoising.</p>
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<p>Composite ensemble learning network architecture.</p>
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<p>Model training curve.</p>
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<p>Comparison with existing methods on drones dataset.</p>
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<p>Impact of batch size on classification accuracy.</p>
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<p>Confusion matrix.</p>
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<p>Scatter plot of first three PCA features.</p>
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<p>Box plot of first four PCA features.</p>
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<p>Box plot of first four PCA features.</p>
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13 pages, 1688 KiB  
Article
Serum Calcium Level at Diagnosis Can Predict Lethal Prostate Cancer Relapse
by Zsolt Fekete, Patricia Ignat, Henrietta Jakab, Nicolae Todor, István Péter László, Alina-Simona Muntean, Sebastian Curcean, Adina Nemeș, Dumitrița Nuțu and Gabriel Kacsó
J. Clin. Med. 2024, 13(16), 4845; https://doi.org/10.3390/jcm13164845 - 16 Aug 2024
Cited by 1 | Viewed by 826
Abstract
Background/Objectives: The most important prognostic factors in curatively treated prostate cancer are T and N stage, histology, grade group and initial PSA. A recent study found that men with blood calcium levels at the high end of the normal range are over [...] Read more.
Background/Objectives: The most important prognostic factors in curatively treated prostate cancer are T and N stage, histology, grade group and initial PSA. A recent study found that men with blood calcium levels at the high end of the normal range are over two-and-a-half times more likely to develop fatal prostate cancer than those with lower calcium levels. However, there is limited evidence regarding the prognostic value of calcium levels at the time of prostate cancer diagnosis. We aimed to determine whether a calcium level in the upper range of normal values has any prognostic value in curatively treated prostate cancer. Methods: We conducted a retrospective analysis of 84 consecutive patients with prostate cancer who underwent curative-intent radiotherapy—either as primary treatment or adjuvant therapy—using external beam radiotherapy with or without brachytherapy. We analyzed all pertinent prognostic factors that could potentially impact disease-free survival. Results: The study revealed that calcium levels at diagnosis significantly predict disease-free survival, whereas the initial PSA level did not hold prognostic significance—likely due to interference from benign prostatic hyperplasia. Conclusions: If our findings are validated, calcium levels at the time of prostate cancer diagnosis could be incorporated into future predictive and prognostic models. Full article
(This article belongs to the Special Issue Clinical Application of Biomarkers in Cancers)
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<p>Overall survival and disease-free survival projected at 10 years for all patients from our analysis.</p>
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<p>Log-rank test to correlate disease-free survival and PSA; <span class="html-italic">p</span>-values do not fall below 0.05.</p>
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<p>Log-rank test to establish if Ca at diagnosis is a prognostic factor for DFS. (Blue line represents the <span class="html-italic">p</span> value at different Ca cut-off values; red straight line represents conventional statistical significance, of 0.05).</p>
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<p>DFS at 10 years of patients with a serum calcium level of more or less than 9.65 mg/dL.</p>
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<p>Log-rank test to determine the prognostic value of alkaline phosphatase. (Blue line represents the <span class="html-italic">p</span> value at different AP cut-off values; red straight line represents conventional statistical significance, of 0.05.)</p>
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23 pages, 793 KiB  
Article
A Physical-Layer Security Cooperative Framework for Mitigating Interference and Eavesdropping Attacks in Internet of Things Environments
by Abdallah Farraj and Eman Hammad
Sensors 2024, 24(16), 5171; https://doi.org/10.3390/s24165171 - 10 Aug 2024
Viewed by 934
Abstract
Intentional electromagnetic interference attacks (e.g., jamming) against wireless connected devices such as the Internet of Things (IoT) remain a serious challenge, especially as such attacks evolve in complexity. Similarly, eavesdropping on wireless communication channels persists as an inherent vulnerability that is often exploited [...] Read more.
Intentional electromagnetic interference attacks (e.g., jamming) against wireless connected devices such as the Internet of Things (IoT) remain a serious challenge, especially as such attacks evolve in complexity. Similarly, eavesdropping on wireless communication channels persists as an inherent vulnerability that is often exploited by adversaries. This article investigates a novel approach to enhancing information security for IoT systems via collaborative strategies that can effectively mitigate attacks targeting availability via interference and confidentiality via eavesdropping. We examine the proposed approach for two use cases. First, we consider an IoT device that experiences an interference attack, causing wireless channel outages and hindering access to transmitted IoT data. A physical-layer-based security (PLS) transmission strategy is proposed in this article to maintain target levels of information availability for devices targeted by adversarial interference. In the proposed strategy, select IoT devices leverage a cooperative transmission approach to mitigate the IoT signal outages under active interference attacks. Second, we consider the case of information confidentiality for IoT devices as they communicate over wireless channels with possible eavesdroppers. In this case, we propose a collaborative transmission strategy where IoT devices create a signal outage for the eavesdropper, preventing it from decoding the signal of the targeted devices. The analytical and numerical results of this article illustrate the effectiveness of the proposed transmission strategy in achieving desired IoT security levels with respect to availability and confidentiality for both use cases. Full article
(This article belongs to the Topic Cyber-Physical Security for IoT Systems)
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<p>Interference attacks problem setup.</p>
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<p>Interference attacks problem model.</p>
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<p>Eavesdropping attacks problem setup.</p>
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<p>Eavesdropping attacks problem model.</p>
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<p>PLS for interference attack defense: impact of the outage constraints on the algorithm success probability (<math display="inline"><semantics> <msub> <mi>ζ</mi> <mi>p</mi> </msub> </semantics></math>).</p>
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<p>PLS for interference attack defense: impact of the outage constraints on the algorithm success probability (<math display="inline"><semantics> <msub> <mi>ζ</mi> <mi>s</mi> </msub> </semantics></math>).</p>
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<p>PLS for interference attack defense: impact of the secondary transmission power on the algorithm success probability.</p>
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<p>PLS for interference attack defense: impact of <math display="inline"><semantics> <msub> <mi>P</mi> <mi>a</mi> </msub> </semantics></math> on the algorithm success probability.</p>
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<p>PLS for eavesdropping attack defense: impact of number of transmitters.</p>
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<p>PLS for eavesdropping attack defense: impact of outage requirement.</p>
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<p>PLS for eavesdropping attack defense: impact of secondary channel strength.</p>
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<p>PLS for eavesdropping attack defense: impact of primary channel strength.</p>
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<p>PLS for eavesdropping attack defense: simulated and theoretical CDF of <math display="inline"><semantics> <msub> <mi>γ</mi> <mi>p</mi> </msub> </semantics></math>.</p>
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<p>PLS for eavesdropping attack defense: moving average of outage probability over time.</p>
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<p>PLS for eavesdropping attack defense: moving average of channel capacity over time.</p>
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<p>PLS for eavesdropping attack defense: algorithm’s success rate versus number of users.</p>
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16 pages, 4331 KiB  
Article
MSD: Multi-Order Semantic Denoising Model for Session-Based Recommendations
by Shulin Cheng, Wentao Huang, Zhenqiang Yu and Jianxing Zheng
Electronics 2024, 13(16), 3118; https://doi.org/10.3390/electronics13163118 - 7 Aug 2024
Viewed by 953
Abstract
Session-based recommendations which aim to predict subsequent user–item interactions based on historical user behaviour during anonymous sessions can be challenging to carry out. Two main challenges need to be addressed and improved: (1) how does one analyze these sessions to accurately and completely [...] Read more.
Session-based recommendations which aim to predict subsequent user–item interactions based on historical user behaviour during anonymous sessions can be challenging to carry out. Two main challenges need to be addressed and improved: (1) how does one analyze these sessions to accurately and completely capture users’ preferences, and (2) how does one identify and eliminate any interference caused by noisy behavior? Existing methods have not adequately addressed these issues since they either neglect the valuable insights that can be gained from analyzing consecutive groups of items or fail to take these noisy data in sessions seriously and handle them properly, which can jointly impede recommendation systems from capturing users’ real intentions. To address these two problems, we designed a multi-order semantic denoising (MSD) model for session-based recommendations. Specifically, we grouped items of different lengths into varying multi-order semantic units to mine the user’s primary intentions from multiple dimensions. Meanwhile, a novel denoising network was designed to alleviate the interference of noisy behavior and provide a more precise session representation. The results of extensive experiments on three real-world datasets demonstrated that the proposed MSD model exhibited improved performance compared with existing state-of-the-art methods in session-based recommendations. Full article
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<p>Instances of items clicked by mistake or out of curiosity, which negatively impact the generation of reliable recommendations.</p>
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<p>The framework of the proposed MSD model.</p>
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<p>The performance of different orders.</p>
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<p>The performance of denoising depths.</p>
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22 pages, 18896 KiB  
Article
Synthetic-Aperture Radar Radio-Frequency Interference Suppression Based on Regularized Optimization Feature Decomposition Network
by Fuping Fang, Haoliang Li, Weize Meng, Dahai Dai and Shiqi Xing
Remote Sens. 2024, 16(14), 2540; https://doi.org/10.3390/rs16142540 - 10 Jul 2024
Viewed by 606
Abstract
Synthetic-aperture radar (SAR) can work in all weather conditions and at all times, and satellite-borne radar has the characteristics of short revisiting period and large imaging width. Therefore, satellite-borne synthetic-aperture radar has been widely deployed, and the SAR images have been widely used [...] Read more.
Synthetic-aperture radar (SAR) can work in all weather conditions and at all times, and satellite-borne radar has the characteristics of short revisiting period and large imaging width. Therefore, satellite-borne synthetic-aperture radar has been widely deployed, and the SAR images have been widely used in geographic mapping, radar interpretation, ship detection, and other fields. Satellite-borne synthetic-aperture radar is also susceptible to various types of intentional or unintentional interference during the imaging process, and because the interference is a direct wave, its power is much stronger than the wave reflected by targets. As a common interference pattern, radio-frequency interference widely exists in various satellite-borne synthetic-aperture radars, which seriously deteriorates SAR image quality. In order to solve the above problems, this paper proposes a feature decomposition network to suppress interference based on regularization optimization. The contributions of this work are as follows: 1. By analyzing the performance limitations of the existing methods, this work proposes a novel regularization method for radio-frequency interference suppression tasks. From the perspective of data distribution histograms and residual components, the proposed method eliminates the variable components introduced by common regularization, greatly reduces the difficulty of data mapping, and significantly improves its robustness and performance. 2. This work proposes a feature decomposition network, where the feature decomposition module contains two parts; one part only represents the interference signal, and the other part only represents the radar signal. The neurons representing the interference signal are discarded, and the neurons representing the radar signal are used as input for the subsequent network. A cosine similarity constraint is used to separate the interference from the network as much as possible. Finally, this method is validated on the MiniSAR dataset and Sentinel-1A dataset. Full article
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<p>A common RFI-polluted image from Sentinel-1A satellite.</p>
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<p>SAR imaging model.</p>
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<p>Feature decomposition network: (<b>a</b>) the total network; (<b>b</b>) feature decomposition block.</p>
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<p>Transformer-based network. (<b>a</b>) Global information extraction module. (<b>b</b>) Local information extraction module.</p>
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<p>Histogram of the interference signal power.</p>
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<p>Histograms of different regularization methods. (<b>a</b>) The first regularization. (<b>b</b>) The second normalization. (<b>c</b>) The third normalization.</p>
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<p>Regularization experiment under narrowband interference. (<b>a</b>) RFI-polluted image. (<b>b</b>) Label. (<b>c</b>) The restored result by UNet-1st. (<b>d</b>) The restored result by Uformer-1st. (<b>e</b>) The restored result by FuSINet-2nd. (<b>f</b>) The restored result by UNet-3rd. (<b>g</b>) The restored result by Uformer-3rd.</p>
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<p>Regularization experiment under chirp wideband interference. (<b>a</b>) RFI-polluted image. (<b>b</b>) Label. (<b>c</b>) The restored result by UNet-1st. (<b>d</b>) The restored result by Uformer-1st. (<b>e</b>) The restored result by FuSINet-2nd. (<b>f</b>) The restored result by UNet-3rd. (<b>g</b>) The restored result by Uformer-3rd.</p>
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<p>Regularization experiment under sinusoidal modulation wideband interference. (<b>a</b>) RFI-polluted image. (<b>b</b>) Label. (<b>c</b>) The restored result by UNet-1st. (<b>d</b>) The restored result by Uformer-1st. (<b>e</b>) The restored result by FuSINet-2nd. (<b>f</b>) The restored result by UNet-3<sup>rd</sup>. (<b>g</b>) The restored result by Uformer-3rd.</p>
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<p>FDNet experiment. (<b>a</b>) RFI-polluted image. (<b>b</b>) Label. (<b>c</b>) The restored result by UNet. (<b>d</b>) The restored result by FD-UNet. (<b>e</b>) The restored result by Uformer.</p>
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<p>Time–frequency spectrograms under narrowband interference. (<b>a</b>) RFI-polluted image. (<b>b</b>) Label. (<b>c</b>) The restored result by notch filter. (<b>d</b>) The restored result by PISNet. (<b>e</b>) The restored result by FuSINet. (<b>f</b>) The restored result by FDNet.</p>
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<p>SAR images under narrowband interference. (<b>a</b>) RFI-polluted image. (<b>b</b>) Label. (<b>c</b>) The restored result by DIFNet. (<b>d</b>) The restored result by PISNet. (<b>e</b>) The restored result by FuSINet. (<b>f</b>) The restored result by FDNet.</p>
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<p>Time–frequency spectrograms under wideband interference. (<b>a</b>) RFI-polluted image. (<b>b</b>) Label. (<b>c</b>) The restored result by notch filter. (<b>d</b>) The restored result by PISNet. (<b>e</b>) The restored result by FuSINet. (<b>f</b>) The restored result by FDNet.</p>
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<p>SAR images under wideband interference. (<b>a</b>) RFI-polluted image. (<b>b</b>) Label. (<b>c</b>) The restored result by DIFNet. (<b>d</b>) The restored result by PISNet. (<b>e</b>) The restored result by FuSINet. (<b>f</b>) The restored result by FDNet.</p>
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<p>SAR image in Sentinel-1A satellite: (<b>a</b>) Global image. (<b>b</b>) Local image.</p>
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<p>Time frequency spectrograms of Sentinel-1A satellite; (<b>a</b>) RFI-polluted image. (<b>b</b>) The restored result by PISNet. (<b>c</b>) The restored result by FuSINet. (<b>d</b>) The restored result by FDNet.</p>
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<p>Sentinel-1A satellite interference suppression results. (<b>a</b>) RFI-polluted image. (<b>b</b>) The restored result by PISNet. (<b>c</b>) The restored result by FuSINet. (<b>d</b>) The restored result by FDNet.</p>
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14 pages, 1524 KiB  
Review
Preservation of Pancreatic Function Should Not Be Disregarded When Performing Pancreatectomies for Pancreatoblastoma in Children
by Traian Dumitrascu
Pediatr. Rep. 2024, 16(2), 385-398; https://doi.org/10.3390/pediatric16020033 - 13 May 2024
Cited by 1 | Viewed by 979
Abstract
Complete surgical resection in the context of a multimodal approach has been associated with excellent long-term survival in children diagnosed with pancreatoblastoma (PB). Traditionally, curative intent surgery for PB implies standard pancreatic resections such as pancreaticoduodenectomies and distal pancreatectomies with splenectomies, surgical procedures [...] Read more.
Complete surgical resection in the context of a multimodal approach has been associated with excellent long-term survival in children diagnosed with pancreatoblastoma (PB). Traditionally, curative intent surgery for PB implies standard pancreatic resections such as pancreaticoduodenectomies and distal pancreatectomies with splenectomies, surgical procedures that may lead to significant long-term pancreatic functional deficiencies. Postoperative pancreatic functional deficiencies are particularly interesting to children because they may interfere with their development, considering their long life expectancy and the significant role of pancreatic functions in their nutritional status and growth. Thus, organ-sparing pancreatectomies, such as spleen-preserving distal pancreatectomies and central pancreatectomies, are emerging in specific tumoral pathologies in children. However, data about organ-sparing pancreatectomies’ potential role in curative-intent PB surgery in children are scarce. Based on the literature data, the current review aims to present the early and late outcomes of pancreatectomies in children (including long-term deficiencies and their potential impact on the development and quality of life), particularly for PB, and further explore the potential role of organ-sparing pancreatectomies for PB. Organ-sparing pancreatectomies are associated with better long-term pancreatic functional outcomes, particularly central pancreatectomies, and have a reduced impact on children’s development and quality of life without jeopardizing their oncological safety. The long-term preservation of pancreatic functions should not be disregarded when performing pancreatectomies for PB in children. A subset of patients with PB might benefit from organ-sparing pancreatectomies, particularly from central pancreatectomies, with the same oncological results as standard pancreatectomies but with significantly less impact on long-term functional outcomes. Full article
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<p>(<b>a</b>) Intraoperative aspects showing a large, relatively exophytic, encapsulated mass (T) into the pancreatic body, compressing but without invading the portal vein (PV); (<b>b</b>) the cut surface of the operative specimen (central pancreatectomy for pancreatoblastoma) showing an encapsulated heterogenous mass with cystic and hemorrhagic components (white arrows) (PH—pancreatic head; PT—pancreatic tail).</p>
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<p>(<b>a</b>) Axial and (<b>b</b>) coronal T2-weighted magnetic resonance images showing a large, relatively exophytic, well-circumscribed mass in the pancreatic body (T) that is heterogeneously hyperintense relative to the nearby pancreatic parenchyma, compressing but without invading the portal vein (*) or superior mesenteric artery (white arrow); (<b>c</b>) axial diffusion-weighted magnetic resonance imaging showing the mass in the pancreatic body (T) with restricted diffusion compared with the nearby pancreatic parenchyma (PH—pancreatic head; PT—pancreatic tail).</p>
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32 pages, 2243 KiB  
Article
The Effects of Supraharmonic Distortion in MV and LV AC Grids
by Andrea Mariscotti and Alessandro Mingotti
Sensors 2024, 24(8), 2465; https://doi.org/10.3390/s24082465 - 11 Apr 2024
Cited by 5 | Viewed by 950
Abstract
Since the integration of electronic devices and intelligent electronic devices into the power grid, power quality (PQ) has consistently remained a significant concern for system operators and experts. Maintaining high standards of power quality is crucial to preventing malfunctions and faults in electric [...] Read more.
Since the integration of electronic devices and intelligent electronic devices into the power grid, power quality (PQ) has consistently remained a significant concern for system operators and experts. Maintaining high standards of power quality is crucial to preventing malfunctions and faults in electric assets and connected loads. Recently, PQ studies have shifted their focus to a specific frequency range, previously not considered problematic—the supraharmonic 2 kHz to 150 kHz range. This range is not populated by easily recognizable harmonic components of the 50 Hz to 60 Hz mains fundamental, but by a combination of intentional emissions, switching non-linearities and byproducts, and various types of resonances. This paper aims to provide a detailed analysis of the impact of supraharmonics (SHs) on power network operation and assets, focusing on the most relevant documented negative effects, namely power loss and the heating of grid elements, aging of dielectric materials, failure of medium voltage (MV) cable terminations, and interference with equipment and power line communication (PLC) technology in particular. Under some shareable assumptions, limits are derived and compared to existing ones for harmonic phenomena, providing a clear identification of the primary issues associated with supraharmonics and suggestions for the standardization process. Strictly related is the problem of grid monitoring and assessment of SH distortion, discussing the suitability of normative requirements for instrument transformers (ITs) with a specific focus on their accuracy. Full article
(This article belongs to the Section Physical Sensors)
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<p>Overview of the negative SH effects showing the cause–effect relationship between them.</p>
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<p>Overview of emission levels: (blue and light blue lines) limits of emissions from EN 50065-1 for PLCs of categories 122 and 134; (purple lines) limits of emissions from EN 50627 for various classes of converters; (magenta line) limits of emissions from EN 55014-1; (pink lines) immunity test levels prescribed by the EN 61000-4-19 (levels 3 and 4); (green curves) IEC 61000-2-4 compatibility levels for classes “1 + 2a”, “2b”, and “3” from bottom to top; (gray/black circles) AIC emissions data taken from IEC 62578 for various categories (&gt;<math display="inline"><semantics> <mrow> <mn>75</mn> <mo> </mo> <mi mathvariant="normal">A</mi> </mrow> </semantics></math>, &lt;<math display="inline"><semantics> <mrow> <mn>75</mn> <mo> </mo> <mi mathvariant="normal">A</mi> </mrow> </semantics></math>, and “C1 and C2”); (green circles) emissions of various PV inverters taken from Uribe-Perez et al. [<a href="#B60-sensors-24-02465" class="html-bibr">60</a>]; (squares) confirmed PLC interference levels, reduced ones after mitigation (circle), with colors indicating various sources (detailed in the legend).</p>
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<p>Bibliometric results: (<b>a</b>) number of sources through the years; (<b>b</b>) subdivision of sources per publication type; (<b>c</b>) shared percentage of prevalent keywords.</p>
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<p>Details of the emission levels of <a href="#sensors-24-02465-f002" class="html-fig">Figure 2</a> with superposed proposed limit curve (dashed gray). Groups “A”, “B”, and “C” are discussed in the text.</p>
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<p>Example of SH limits for the three sub-bands (2 kHz to 9 kHz, 9 kHz to 50 kHz, and 50 kHz to 150 kHz): current (light blue) and derived voltage distortion value (light brown). On the left-hand side, the corresponding current limits for the harmonic interval are visible. (<b>a</b>) Residential environment (reference standard IEC 61000-3-2 [<a href="#B82-sensors-24-02465" class="html-bibr">82</a>], Class D equipment); (<b>b</b>) industrial environment (reference standard IEC 61000-3-12 [<a href="#B83-sensors-24-02465" class="html-bibr">83</a>]).</p>
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<p>Limit curves for the percent SH voltage distortion based on the assumed <math display="inline"><semantics> <mrow> <msub> <mi>Q</mi> <mrow> <mi>l</mi> <mi>i</mi> <mi>m</mi> </mrow> </msub> <mo>=</mo> <mn>20</mn> </mrow> </semantics></math> of [<a href="#B20-sensors-24-02465" class="html-bibr">20</a>] and for <span class="html-italic">m</span> values covering <span style="color: #007F00"><math display="inline"><semantics> <mrow> <mi>m</mi> <mo>&lt;</mo> <mo>=</mo> <mn>0.25</mn> </mrow> </semantics></math></span>, <span style="color: #D8A533"><math display="inline"><semantics> <mrow> <mn>0.25</mn> <mo>&lt;</mo> <mi>m</mi> <mo>&lt;</mo> <mo>=</mo> <mn>0.5</mn> </mrow> </semantics></math></span>, <span style="color: #B26319"><math display="inline"><semantics> <mrow> <mn>0.5</mn> <mo>&lt;</mo> <mi>m</mi> <mo>&lt;</mo> <mo>=</mo> <mn>1.0</mn> </mrow> </semantics></math></span>, and <span style="color: #FF0000"><math display="inline"><semantics> <mrow> <mi>m</mi> <mo>&gt;</mo> <mn>1.0</mn> </mrow> </semantics></math></span>, with meaning of colors as in [<a href="#B20-sensors-24-02465" class="html-bibr">20</a>], namely “no risk”, “moderate risk”, “significant risk”, and “unacceptable”.</p>
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<p>Accuracy limits vs. frequency as specified in the IEC 61869 standards (for the moment limited to 20 kHz).</p>
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<p>Overview of negative SH effects (in order of priority, or criticality, from <span style="color: #FF7F00"><b>lowest</b></span> to <span style="color: #8C4400"><b>highest</b></span> and derived limits.</p>
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20 pages, 2450 KiB  
Article
Multimodal, Technology-Assisted Intervention for the Management of Menopause after Cancer Improves Cancer-Related Quality of Life—Results from the Menopause after Cancer (Mac) Study
by Fionán Donohoe, Yvonne O’Meara, Aidin Roberts, Louise Comerford, Ivaila Valcheva, Una Kearns, Marie Galligan, Michaela J. Higgins, Alasdair L. Henry, Catherine M. Kelly, Janice M. Walshe, Martha Hickey and Donal J. Brennan
Cancers 2024, 16(6), 1127; https://doi.org/10.3390/cancers16061127 - 12 Mar 2024
Viewed by 2916
Abstract
Background: Vasomotor symptoms (VMSs) associated with menopause represent a significant challenge for many patients after cancer treatment, particularly if conventional menopausal hormone therapy (MHT) is contraindicated. Methods: The Menopause after Cancer (MAC) Study (NCT04766229) was a single-arm phase II trial examining the impact [...] Read more.
Background: Vasomotor symptoms (VMSs) associated with menopause represent a significant challenge for many patients after cancer treatment, particularly if conventional menopausal hormone therapy (MHT) is contraindicated. Methods: The Menopause after Cancer (MAC) Study (NCT04766229) was a single-arm phase II trial examining the impact of a composite intervention consisting of (1) the use of non-hormonal pharmacotherapy to manage VMS, (2) digital cognitive behavioral therapy for insomnia (dCBT-I) using Sleepio (Big Health), (3) self-management strategies for VMS delivered via the myPatientSpace mobile application and (4) nomination of an additional support person/partner on quality of life (QoL) in women with moderate-to-severe VMS after cancer. The primary outcome was a change in cancer-specific global QoL assessed by the EORTC QLC C-30 v3 at 6 months. Secondary outcomes included the frequency of VMS, the bother/interference of VMS and insomnia symptoms. Results: In total, 204 women (82% previous breast cancer) with a median age of 49 years (range 28–66) were recruited. A total of 120 women completed the protocol. Global QoL scores increased from 62.2 (95%CI 58.6–65.4) to 70.4 (95%CI 67.1–73.8) at 6 months (p < 0.001) in the intention to treatment (ITT) cohort (n = 204) and from 62 (95%CI 58.6–65.4) to 70.4 (95%CI 67.1–73.8) at 6 months (p < 0.001) in the per-protocol (PP) cohort (n = 120). At least 50% reductions were noticed in the frequency of VMS as well as the degree of bother/interference of VMS at six months. The prevalence of insomnia reduced from 93.1% at the baseline to 45.2% at 6 months (p < 0.001). The Sleep Condition Indicator increased from 8.5 (SEM 0.4) to 17.3 (SEM 0.5) (p < 0.0005) in the ITT cohort and 7.9 (SEM 0.4) to 17.3 (SEM 0.5) (p < 0.001) in the PP cohort. Conclusions: A targeted composite intervention improves the quality of life for cancer patients with frequent and bothersome vasomotor symptoms with additional benefits on frequency, the bother/interference of VMS and insomnia symptoms. Full article
(This article belongs to the Section Cancer Survivorship and Quality of Life)
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<p>(<b>A</b>): Schematic representing the composite intervention of the MAC study. (<b>B</b>): Flowchart demonstrating specifics of the composite intervention in the MAC study.</p>
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<p>(<b>A</b>): Schematic representing the composite intervention of the MAC study. (<b>B</b>): Flowchart demonstrating specifics of the composite intervention in the MAC study.</p>
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<p>Compliance with MAC intervention. (<b>A</b>): Graph demonstrating the number of participants who completed the EORTC-QLQ-C30 questionnaire at each timepoint. (<b>B</b>): Chart demonstrating how often each regimen was prescribed in the study. (<b>C</b>): Graph demonstrating compliance with each drug regimen over the course of the study. (<b>D</b>): Graph demonstrating the number of participants who completed each of the six sessions of dCBT-I in Sleepio.</p>
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<p>Changes in all scales of the EORTC-QLQ-C30 in the ITT and PP cohorts. (<b>A</b>): Mean and 95% CI in the global health status scale in the EORTC-QLQ-C30 instrument for the ITT cohort (shown in black) and the PP cohort (shown in blue). (<b>B</b>): Box plot showing global health status scores categorized according to low, mid or high global health status scores at the baseline. Those with the lowest scores at baseline saw the greatest improvement in these scores. *** denotes statistical significance &lt; 0.005.</p>
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<p>Changes in menopause and sleep outcomes ITT and PP cohorts. (<b>A</b>): Mean and 95% CI for the frequency of daytime hot flashes for the ITT cohort (shown in black) and the PP cohort (shown in blue) over the study period. (<b>B</b>): Mean and 95% CI for the frequency of night sweats for the ITT cohort (shown in black) and the PP cohort (shown in blue) over the study period. (<b>C</b>): Mean and 95% CI frequency for all VMSs for the ITT cohort (shown in black) and the PP cohort (shown in blue) over the study period. (<b>D</b>): Mean and 95% CI for Hot Flush Rating Scale scores in the ITT cohort (shown in black) and the PP cohort (shown in blue). (<b>E</b>): Mean and SEM for the Sleep Condition Indicator in the ITT cohort (shown in black) and the PP cohort (shown in blue). * denotes statistical significance &lt;0.05, *** denotes statistical significance &lt;0.005.</p>
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<p>Changes in menopause and sleep outcomes ITT and PP cohorts. (<b>A</b>): Mean and 95% CI for the frequency of daytime hot flashes for the ITT cohort (shown in black) and the PP cohort (shown in blue) over the study period. (<b>B</b>): Mean and 95% CI for the frequency of night sweats for the ITT cohort (shown in black) and the PP cohort (shown in blue) over the study period. (<b>C</b>): Mean and 95% CI frequency for all VMSs for the ITT cohort (shown in black) and the PP cohort (shown in blue) over the study period. (<b>D</b>): Mean and 95% CI for Hot Flush Rating Scale scores in the ITT cohort (shown in black) and the PP cohort (shown in blue). (<b>E</b>): Mean and SEM for the Sleep Condition Indicator in the ITT cohort (shown in black) and the PP cohort (shown in blue). * denotes statistical significance &lt;0.05, *** denotes statistical significance &lt;0.005.</p>
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<p>CONSORT diagram for the MAC study.</p>
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38 pages, 20966 KiB  
Article
Decoupling and Cloaking of Rectangular and Circular Patch Antennas and Interleaved Antenna Arrays with Planar Coated Metasurfaces at C-Band Frequencies—Design and Simulation Study
by Shefali Pawar, Doojin Lee, Harry Skinner, Seong-Youp Suh and Alexander Yakovlev
Sensors 2024, 24(1), 291; https://doi.org/10.3390/s24010291 - 3 Jan 2024
Cited by 3 | Viewed by 1684
Abstract
An electromagnetic cloaking approach is employed with the intention to curb the destructive effects of mutual interference for rectangular and circularly shaped patch antennas situated in a tight spacing. Primarily, we show that by coating the top surface of each patch with an [...] Read more.
An electromagnetic cloaking approach is employed with the intention to curb the destructive effects of mutual interference for rectangular and circularly shaped patch antennas situated in a tight spacing. Primarily, we show that by coating the top surface of each patch with an appropriately designed metasurface, the mutual coupling is considerably reduced between the antennas. Furthermore, the cloak construct is extended to a tightly spaced, interleaved linear patch antenna array configuration and it is shown that the coated metasurfaces successfully enhance the performance of each array in terms of their matching characteristics, total efficiencies and far-field realized gain patterns for a broad range of beam-scan angles. For rectangular patches, the cloaked Array I and II achieve corresponding peak total efficiencies of 93% and 90%, in contrast to the total efficiencies of 57% and 21% for uncloaked Array I and II, respectively, at their operating frequencies. Moreover, cloaked rectangular Array I and II exhibit main lobe gains of 13.2 dB and 13.8 dB, whereas uncloaked Array I and II only accomplish main lobe gains of 10 dB and 5.5 dB, respectively. Likewise, for the cloaked circular patches, corresponding total efficiencies of 91% and 89% are recorded for Array I and II, at their operating frequencies (uncloaked Array I and II show peak efficiencies of 71% and 55%, respectively). The main lobe gain for each cloaked circular patch array is approximately 14.2 dB, whereas the uncloaked Array I and II only achieve maximum gains of 10.5 dB and 7.5 dB, respectively. Full article
(This article belongs to the Special Issue 5G Antennas)
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<p>Schematic design configurations: (<b>a</b>) Isolated Patch I and (<b>b</b>) Isolated Patch II.</p>
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<p>Schematics for (<b>a</b>) Uncloaked Patch I and II, (<b>b</b>) unfolded view of the cloak design for the patches, (<b>c</b>) Cloaked Patch I and II, and (<b>d</b>) side view of the cloaked rectangular patches, detailing the structural parameters of the coated metasurfaces.</p>
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<p>Parametric analysis using the reflection coefficients (<math display="inline"><semantics> <mrow> <mfenced open="|" close="|" separators="|"> <mrow> <msub> <mrow> <mi>S</mi> </mrow> <mrow> <mn>11</mn> </mrow> </msub> </mrow> </mfenced> </mrow> </semantics></math>) for (<b>a</b>) relative permittivity <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>ε</mi> </mrow> <mrow> <mi>c</mi> <mn>1</mn> </mrow> </msub> </mrow> </semantics></math> of the supporting dielectric material, (<b>b</b>) thickness of the dielectric <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>h</mi> </mrow> <mrow> <mi>c</mi> <mn>1</mn> </mrow> </msub> </mrow> </semantics></math>, (<b>c</b>) vertical slot placement <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>D</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> </mrow> </semantics></math>, and (<b>d</b>) horizontal slot placement <math display="inline"><semantics> <mrow> <msub> <mrow> <mn>2</mn> <mi>D</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> </mrow> </semantics></math> for the cloak design of Patch I.</p>
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<p>Cross-sectional view of the surface currents: (<b>a</b>) uncloaked and (<b>b</b>) cloaked Patch I at the cloaking frequency.</p>
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<p>Plots for (<b>a</b>) total efficiencies, (<b>b</b>) radiation efficiencies, and electric field contours at <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz for (<b>c</b>) uncloaked and (<b>d</b>) cloaked Patch I.</p>
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<p>S-parameter plots for (<b>a</b>) coupled uncloaked and (<b>b</b>) decoupled cloaked rectangular patch antennas.</p>
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<p>Total efficiencies when (<b>a</b>) Patch I is active and (<b>b</b>) Patch II is active.</p>
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<p>Electric field contours for the two rectangular patches placed close together: (<b>a</b>) coupled uncloaked (without cloaks) and (<b>b</b>) decoupled cloaked (with cloaks) cases, when Patch I (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz) is active, and similarly for (<b>c</b>) uncloaked and (<b>d</b>) cloaked cases, when Patch II (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>5.2</mn> </mrow> </semantics></math> GHz) is active.</p>
Full article ">Figure 9
<p>Realized gain patterns at (<b>a</b>)<math display="inline"><semantics> <mrow> <mo> </mo> <mi>φ</mi> <mo>=</mo> <msup> <mrow> <mn>0</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <mi>θ</mi> <mo>=</mo> <msup> <mrow> <mn>90</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math> for Patch I (at frequency <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz), and at (<b>c</b>)<math display="inline"><semantics> <mrow> <mo> </mo> <mi>φ</mi> <mo>=</mo> <msup> <mrow> <mn>0</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>d</b>) <math display="inline"><semantics> <mrow> <mi>θ</mi> <mo>=</mo> <msup> <mrow> <mn>90</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math> for Patch II (at frequency <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>5.2</mn> </mrow> </semantics></math> GHz).</p>
Full article ">Figure 10
<p>E-field plots showing co-polar and cross-polar radiations for the cloaked configurations of (<b>a</b>) Patch I at <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz and (<b>b</b>) Patch II at <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>5.2</mn> </mrow> </semantics></math> GHz.</p>
Full article ">Figure 11
<p>(<b>a</b>) Cross-sectional view of Patch I coated with the metasurface cloak, (<b>b</b>) total RCS plot for Patch I and E-field plots for (<b>c</b>) uncloaked Patch I at <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz, (<b>d</b>) cloaked Patch I at <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz, and (<b>e</b>) cloaked Patch I at <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>5.2</mn> </mrow> </semantics></math> GHz in presence of a normally incident TM polarized plane wave.</p>
Full article ">Figure 12
<p>Schematic configurations of (<b>a</b>) uncloaked and (<b>b</b>) cloaked rectangular patch antenna arrays.</p>
Full article ">Figure 13
<p>(<b>a</b>) Active reflection coefficients, (<b>b</b>) active coupling coefficients for uncloaked (coupled) Array I, (<b>c</b>) active reflection coefficients, and (<b>d</b>) active coupling coefficients for cloaked (decoupled) Array I (resonance frequency <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz).</p>
Full article ">Figure 14
<p>(<b>a</b>) Active reflection coefficients, (<b>b</b>) active coupling coefficients for uncloaked (coupled) Array II, (<b>c</b>) active reflection coefficients, and (<b>d</b>) active coupling coefficients for cloaked (decoupled) Array II (resonance frequency <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>5.2</mn> </mrow> </semantics></math> GHz).</p>
Full article ">Figure 15
<p>Plots for total efficiencies: (<b>a</b>) Array I (resonance frequency <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz) active and (<b>b</b>) Array II (resonance frequency <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>5.2</mn> </mrow> </semantics></math> GHz) active.</p>
Full article ">Figure 16
<p>Electric field contours for (<b>a</b>) uncloaked and (<b>b</b>) cloaked patch antenna arrays when Array I (operating frequency, <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz) is active; (<b>c</b>) uncloaked and (<b>d</b>) cloaked patch antenna arrays when Array II (operating frequency, <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>5.2</mn> </mrow> </semantics></math> GHz) is active.</p>
Full article ">Figure 17
<p>Active VSWR plots for (<b>a</b>) uncloaked coupled and (<b>b</b>) cloaked decoupled Array I (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz), and isolation parameter plots for (<b>c</b>) uncloaked coupled and (<b>d</b>) cloaked decoupled Array I, at scan angle = <math display="inline"><semantics> <mrow> <msup> <mrow> <mn>20</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>.</p>
Full article ">Figure 18
<p>Active VSWR plots for (<b>a</b>) uncloaked coupled and (<b>b</b>) cloaked decoupled Array I (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz), and isolation parameter plots for (<b>c</b>) uncloaked coupled and (<b>d</b>) cloaked decoupled Array I, at scan angle = <math display="inline"><semantics> <mrow> <msup> <mrow> <mn>30</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>.</p>
Full article ">Figure 19
<p>Realized gain plots for Array I (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.9</mn> </mrow> </semantics></math> GHz) showing beam scanning at scan angles (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mn>0</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mo>−</mo> <mn>10</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mo>−</mo> <mn>45</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, and (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mn>20</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>.</p>
Full article ">Figure 20
<p>Realized gain plots for Array II (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>5.2</mn> </mrow> </semantics></math> GHz) showing beam scanning at angles (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mn>0</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mo>−</mo> <mn>10</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mo>−</mo> <mn>45</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, and (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mn>30</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>.</p>
Full article ">Figure 21
<p>Schematics for (<b>a</b>) uncloaked circular Patch I and II, (<b>b</b>) cross-sectional side view of the uncloaked coupled patches, (<b>c</b>) cloaked Patch I and II, (<b>d</b>) side view of the cloaked circular patches, detailing the structural parameters of the coated metasurfaces, and (<b>e</b>) unfolded view of the cloak design.</p>
Full article ">Figure 22
<p>Plots for S-parameters: (<b>a</b>) uncloaked coupled and (<b>b</b>) cloaked decoupled patch antennas and plots for total efficiencies: (<b>c</b>) Patch I is active and (<b>d</b>) Patch II is active.</p>
Full article ">Figure 23
<p>Electric field contours for (<b>a</b>) uncloaked coupled and (<b>b</b>) cloaked decoupled cases when Patch I is active (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.5</mn> </mrow> </semantics></math> GHz), and (<b>c</b>) uncloaked coupled and (<b>d</b>) cloaked decoupled cases when Patch II is active (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>4.7</mn> </mrow> </semantics></math> GHz).</p>
Full article ">Figure 24
<p>Realized gain patterns at (<b>a</b>)<math display="inline"><semantics> <mrow> <mo> </mo> <mi>φ</mi> <mo>=</mo> <msup> <mrow> <mn>0</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <mi>θ</mi> <mo>=</mo> <msup> <mrow> <mn>90</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math> for Patch I (at <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.5</mn> </mrow> </semantics></math> GHz), and at (<b>c</b>)<math display="inline"><semantics> <mrow> <mo> </mo> <mi>φ</mi> <mo>=</mo> <msup> <mrow> <mn>0</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>d</b>) <math display="inline"><semantics> <mrow> <mi>θ</mi> <mo>=</mo> <msup> <mrow> <mn>90</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math> for Patch II (at <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>4.7</mn> </mrow> </semantics></math> GHz).</p>
Full article ">Figure 25
<p>(<b>a</b>) Cross-sectional side view, (<b>b</b>) total RCS plot for cloaked Patch I, and E-field distributions for cloaked Patch I at (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.5</mn> </mrow> </semantics></math> GHz, (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>4.7</mn> </mrow> </semantics></math> GHz in presence of a normally incident TM polarized plane wave.</p>
Full article ">Figure 26
<p>Schematic configurations of (<b>a</b>) uncloaked and (<b>b</b>) cloaked interleaved circular patch antenna arrays.</p>
Full article ">Figure 27
<p>Plots for total efficiencies: (<b>a</b>) Array I (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.5</mn> </mrow> </semantics></math> GHz) active and (<b>b</b>) Array II (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>4.7</mn> </mrow> </semantics></math> GHz) active.</p>
Full article ">Figure 28
<p>(<b>a</b>) Active reflection coefficients, (<b>b</b>) active coupling coefficients for uncloaked (coupled) Array I, (<b>c</b>) active reflection coefficients, and (<b>d</b>) active coupling coefficients for cloaked (decoupled) Array I (resonance frequency–<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.5</mn> </mrow> </semantics></math> GHz).</p>
Full article ">Figure 29
<p>(<b>a</b>) Active reflection coefficients, (<b>b</b>) active coupling coefficients for uncloaked (coupled) Array II, (<b>c</b>) active reflection coefficients, and (<b>d</b>) active coupling coefficients for cloaked (decoupled) Array II (resonance frequency–<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>4.7</mn> </mrow> </semantics></math> GHz).</p>
Full article ">Figure 30
<p>E-field contours: (<b>a</b>) uncloaked and (<b>b</b>) cloaked patch antenna arrays when Array I is active and (<b>c</b>) uncloaked and (<b>d</b>) cloaked patch antenna arrays when Array II is active.</p>
Full article ">Figure 31
<p>Realized gain polar plots for Array I (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>=</mo> <mn>4.5</mn> </mrow> </semantics></math> GHz) at scan angles (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mo>−</mo> <mn>10</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mn>20</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>, and (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mo>−</mo> <mn>30</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>.</p>
Full article ">Figure 32
<p>Realized gain polar plots for Array II (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>f</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mn>4.7</mn> </mrow> </semantics></math> GHz) at scan angles (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mn>10</mn> <mo>°</mo> </msup> </mrow> </semantics></math> and (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>θ</mi> </mrow> <mrow> <mi>s</mi> </mrow> </msub> <mo>=</mo> <msup> <mrow> <mo>−</mo> <mn>20</mn> </mrow> <mrow> <mo>°</mo> </mrow> </msup> </mrow> </semantics></math>.</p>
Full article ">
8 pages, 1495 KiB  
Proceeding Paper
Antiference: New Concept for Evolutive Mitigation of RFI to GNSS
by Shahrzad Afroozeh, Vincent Bejach, Uros Bokan, André Bos, Bastiaan Ober and Sascha Bartl
Eng. Proc. 2023, 54(1), 61; https://doi.org/10.3390/ENC2023-15451 - 29 Oct 2023
Viewed by 551
Abstract
The past decade has shown a growing awareness of the dangers of intentional interference (especially jamming and spoofing) with GNSS signals. The Antiference project uses reconfigurable digital signal processing methods in the detection, classification, and mitigation of interference by employing machine learning techniques. [...] Read more.
The past decade has shown a growing awareness of the dangers of intentional interference (especially jamming and spoofing) with GNSS signals. The Antiference project uses reconfigurable digital signal processing methods in the detection, classification, and mitigation of interference by employing machine learning techniques. The ML-based jamming classifier uses distinctive features of spectrograms for the differentiation of various jamming attacks. A residual neural net is used to map the spectrograms to the different jamming types. It relies on a fingerprinting architecture. Fingerprints summarize the characteristics of all the incoming signals, which are stored in and matched to a database of previously encountered interference types. To validate the implemented functionalities, a developed test-bed runs test scenarios and benchmarks the results against two state-of-the-art COTS receivers with interference mitigation capabilities. Full article
(This article belongs to the Proceedings of European Navigation Conference ENC 2023)
Show Figures

Figure 1

Figure 1
<p>Detection and classification models used in Antiference for jamming (<b>left</b>) and spoofing (<b>right</b>).</p>
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<p>Antiference testbed architecture.</p>
Full article ">Figure 3
<p>The improvement in observed C/N0 in the presence of FM interference for nine of our recordings (that are depicted head to tail). Antiference shows a better interference suppression than the Rec02 COTS receiver.</p>
Full article ">Figure 4
<p>Antiference RFI classification outputs for the first recording from <a href="#engproc-54-00061-f004" class="html-fig">Figure 4</a>. FM interference is hard to distinguish from AM interference and is sometimes mistaken for CW interference. As the mitigation of these types of interference is the same, this does not impact mitigation performance.</p>
Full article ">
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