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Search Results (1,193)

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16 pages, 577 KiB  
Systematic Review
Blood Biomarkers as Optimization Tools for Computed Tomography in Mild Traumatic Brain Injury Management in Emergency Departments: A Systematic Review
by Ángela Caballero Ballesteros, María Isabel Alonso Gallardo and Juan Mora-Delgado
J. Pers. Med. 2025, 15(8), 350; https://doi.org/10.3390/jpm15080350 (registering DOI) - 3 Aug 2025
Abstract
Background/Objectives: Traumatic brain injury (TBI), especially mild TBI (mTBI), is frequently caused by traffic accidents, falls, or sports injuries. Although computed tomography (CT) is the gold standard for diagnosis, overuse can lead to unnecessary radiation exposure, increased healthcare costs, and emergency department [...] Read more.
Background/Objectives: Traumatic brain injury (TBI), especially mild TBI (mTBI), is frequently caused by traffic accidents, falls, or sports injuries. Although computed tomography (CT) is the gold standard for diagnosis, overuse can lead to unnecessary radiation exposure, increased healthcare costs, and emergency department saturation. Blood-based biomarkers have emerged as potential tools to optimize CT scan use. This systematic review aims to evaluate recent evidence on the role of specific blood biomarkers in guiding CT decisions in patients with mTBI. Methods: A systematic search was conducted in the PubMed, Cochrane, and CINAHL databases for studies published between 2020 and 2024. Inclusion criteria focused on adult patients with mTBI evaluated using both CT imaging and at least one of the following biomarkers: glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), and S100 calcium-binding protein B (S100B). After screening, six studies were included in the final review. Results: All included studies reported high sensitivity and negative predictive value for the selected biomarkers in detecting clinically relevant intracranial lesions. GFAP and UCH-L1, particularly in combination, consistently identified low-risk patients who could potentially forgo CT scans. While S100B also showed high sensitivity, discrepancies in cutoff values across studies highlighted the need for harmonization. Conclusions: Blood biomarkers such as GFAP, UCH-L1, and S100B demonstrate strong potential to reduce unnecessary CT imaging in mTBI by identifying patients at low risk of significant brain injury. Future research should focus on standardizing biomarker thresholds and validating protocols to support their integration into clinical practice guidelines. Full article
25 pages, 7503 KiB  
Article
A Diagnostic Framework for Decoupling Multi-Source Vibrations in Complex Machinery: An Improved OTPA Application on a Combine Harvester Chassis
by Haiyang Wang, Zhong Tang, Liyun Lao, Honglei Zhang, Jiabao Gu and Qi He
Appl. Sci. 2025, 15(15), 8581; https://doi.org/10.3390/app15158581 (registering DOI) - 1 Aug 2025
Abstract
Complex mechanical systems, such as agricultural combine harvesters, are subjected to dynamic excitations from multiple coupled sources, compromising structural integrity and operational reliability. Disentangling these vibrations to identify dominant sources and quantify their transmission paths remains a significant engineering challenge. This study proposes [...] Read more.
Complex mechanical systems, such as agricultural combine harvesters, are subjected to dynamic excitations from multiple coupled sources, compromising structural integrity and operational reliability. Disentangling these vibrations to identify dominant sources and quantify their transmission paths remains a significant engineering challenge. This study proposes a robust diagnostic framework to address this issue. We employed a multi-condition vibration test with sequential source activation and an improved Operational Transfer Path Analysis (OTPA) method. Applied to a harvester chassis, the results revealed that vibration energy is predominantly concentrated in the 0–200 Hz frequency band. Path contribution analysis quantified that the “cutting header → conveyor trough → hydraulic cylinder → chassis frame” path is the most critical contributor to vertical vibration, with a vibration acceleration level of 117.6 dB. Further analysis identified the engine (29.3 Hz) as the primary source for vertical vibration, while lateral vibration was mainly attributed to a coupled resonance between the threshing cylinder (58 Hz) and the engine’s second-order harmonic. This study’s theoretical contribution lies in validating a powerful methodology for vibration source apportionment in complex systems. Practically, the findings provide direct, actionable insights for targeted structural optimization and vibration suppression. Full article
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13 pages, 414 KiB  
Essay
Zhuangzi’s De 德 and Transcendence: The Temporal Order of “Ten Suns Rose in the Sky at Once” in the Qiwu lun 齊物論
by Yuqi Lv and Gongyu Chen
Religions 2025, 16(8), 995; https://doi.org/10.3390/rel16080995 (registering DOI) - 30 Jul 2025
Viewed by 226
Abstract
The phrase shiri bing chu 十日並出 (ten suns rose in the sky at once) from the Qiwu lun 齊物論 can also be interpreted as shiri dai chu 十日代出 (ten suns alternately appearing). Here, “ten suns rose in the sky at once” is not [...] Read more.
The phrase shiri bing chu 十日並出 (ten suns rose in the sky at once) from the Qiwu lun 齊物論 can also be interpreted as shiri dai chu 十日代出 (ten suns alternately appearing). Here, “ten suns rose in the sky at once” is not merely a spatial concept but also a temporal one. Thus, the concept of De 德 (virtue), connected to the idea of “ten suns shining together,” is a transcendent force with its own inner sense of time. It acts as the foundation for all things to exist and grow continuously. Under the endless cycle of day and night and the nourishing power of tiande 天德 (heavenly virtue), everything flourishes according to its true nature. Here, De combines two aspects: mingde 明德 (luminous virtue) and xuande 玄德 (inconspicuous virtue). “luminous virtue” focuses on order and building, highlighting the uniqueness within human growth. “inconspicuous virtue” emphasizes harmony and equalizing with all things, revealing our shared connection with the world. These two concepts are not opposites. The highest goal of luminous virtue lies in mysterious virtue, which itself contains the roots of luminous virtue. Both work together to reflect the natural flow of the Dao 道 (the Way), thus demonstrating that Zhuangzi’s philosophy is not merely about criticism or deconstruction—it has a deeply constructive side. Virtue transcends both individuality and universality. Human nature holds both virtues. By balancing the order of growth and equalizing with all things, we can harmonize our uniqueness with our shared bonds, revealing our true value in both action and spirit. Full article
16 pages, 2562 KiB  
Article
Harmonic and Interharmonic Measurement Method Using Two-Fold Compound Convolution Windows and Zoom Fast Fourier Transform
by Xiangui Xiao, Lei Zhao, Shengjun Zhou, Haijun Liu, Zhong Fu and Dan Hu
Energies 2025, 18(15), 4047; https://doi.org/10.3390/en18154047 - 30 Jul 2025
Viewed by 162
Abstract
With the rapidly increasing penetration of new energy resources, the power grid faces significant threats from harmonics. To measure and suppress these harmonics, numerous harmonic measurement methods have been proposed. However, accurately identifying the parameters of harmonics and interharmonics remains challenging. To address [...] Read more.
With the rapidly increasing penetration of new energy resources, the power grid faces significant threats from harmonics. To measure and suppress these harmonics, numerous harmonic measurement methods have been proposed. However, accurately identifying the parameters of harmonics and interharmonics remains challenging. To address this issue, we propose a new method that combines two-fold convolution windows and ZoomFFT. This method leverages the advantages of low side lobe peaks and high side lobe attenuation rates of compound convolution windows to suppress spectral leakage. Additionally, a six-spectral-line interpolation method is employed to correct the calculation results. Furthermore, ZoomFFT is utilized to locally amplify the spectrum, enabling the distinction between interharmonics and harmonics with closely spaced frequencies. The simulation results demonstrate that the proposed algorithm effectively identifies interharmonics with similar frequencies, outperforming single-window functions and ZoomFFT in terms of accuracy. Full article
(This article belongs to the Section F: Electrical Engineering)
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17 pages, 6326 KiB  
Article
Dynamic Stress Wave Response of Thin-Walled Circular Cylindrical Shell Under Thermal Effects and Axial Harmonic Compression Boundary Condition
by Desejo Filipeson Sozinando, Patrick Nziu, Bernard Xavier Tchomeni and Alfayo Anyika Alugongo
Appl. Mech. 2025, 6(3), 55; https://doi.org/10.3390/applmech6030055 - 28 Jul 2025
Viewed by 345
Abstract
The interaction between thermal fields and mechanical loads in thin-walled cylindrical shells introduces complex dynamic behaviors relevant to aerospace and mechanical engineering applications. This study investigates the axial stress wave propagation in a circular cylindrical shell subjected to combined thermal gradients and time-dependent [...] Read more.
The interaction between thermal fields and mechanical loads in thin-walled cylindrical shells introduces complex dynamic behaviors relevant to aerospace and mechanical engineering applications. This study investigates the axial stress wave propagation in a circular cylindrical shell subjected to combined thermal gradients and time-dependent harmonic compression. A semi-analytical model based on Donnell–Mushtari–Vlasov (DMV) shells theory is developed to derive the governing equations, incorporating elastic, inertial, and thermal expansion effects. Modal solutions are obtained to evaluate displacement and stress distributions across varying thermal and mechanical excitation conditions. Empirical Mode Decomposition (EMD) and Instantaneous Frequency (IF) analysis are employed to extract time–frequency characteristics of the dynamic response. Complementary Finite Element Analysis (FEA) is conducted to assess modal deformations, stress wave amplification, and the influence of thermal softening on resonance frequencies. Results reveal that increasing thermal gradients leads to significant reductions in natural frequencies and amplifies stress responses at critical excitation frequencies. The combination of analytical and numerical approaches captures the coupled thermomechanical effects on shell dynamics, providing an understanding of resonance amplification, modal energy distribution, and thermal-induced stiffness variation under axial harmonic excitation across thin-walled cylindrical structures. Full article
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23 pages, 2002 KiB  
Article
Precision Oncology Through Dialogue: AI-HOPE-RTK-RAS Integrates Clinical and Genomic Insights into RTK-RAS Alterations in Colorectal Cancer
by Ei-Wen Yang, Brigette Waldrup and Enrique Velazquez-Villarreal
Biomedicines 2025, 13(8), 1835; https://doi.org/10.3390/biomedicines13081835 - 28 Jul 2025
Viewed by 428
Abstract
Background/Objectives: The RTK-RAS signaling cascade is a central axis in colorectal cancer (CRC) pathogenesis, governing cellular proliferation, survival, and therapeutic resistance. Somatic alterations in key pathway genes—including KRAS, NRAS, BRAF, and EGFR—are pivotal to clinical decision-making in precision oncology. However, the integration of [...] Read more.
Background/Objectives: The RTK-RAS signaling cascade is a central axis in colorectal cancer (CRC) pathogenesis, governing cellular proliferation, survival, and therapeutic resistance. Somatic alterations in key pathway genes—including KRAS, NRAS, BRAF, and EGFR—are pivotal to clinical decision-making in precision oncology. However, the integration of these genomic events with clinical and demographic data remains hindered by fragmented resources and a lack of accessible analytical frameworks. To address this challenge, we developed AI-HOPE-RTK-RAS, a domain-specialized conversational artificial intelligence (AI) system designed to enable natural language-based, integrative analysis of RTK-RAS pathway alterations in CRC. Methods: AI-HOPE-RTK-RAS employs a modular architecture combining large language models (LLMs), a natural language-to-code translation engine, and a backend analytics pipeline operating on harmonized multi-dimensional datasets from cBioPortal. Unlike general-purpose AI platforms, this system is purpose-built for real-time exploration of RTK-RAS biology within CRC cohorts. The platform supports mutation frequency profiling, odds ratio testing, survival modeling, and stratified analyses across clinical, genomic, and demographic parameters. Validation included reproduction of known mutation trends and exploratory evaluation of co-alterations, therapy response, and ancestry-specific mutation patterns. Results: AI-HOPE-RTK-RAS enabled rapid, dialogue-driven interrogation of CRC datasets, confirming established patterns and revealing novel associations with translational relevance. Among early-onset CRC (EOCRC) patients, the prevalence of RTK-RAS alterations was significantly lower compared to late-onset disease (67.97% vs. 79.9%; OR = 0.534, p = 0.014), suggesting the involvement of alternative oncogenic drivers. In KRAS-mutant patients receiving Bevacizumab, early-stage disease (Stages I–III) was associated with superior overall survival relative to Stage IV (p = 0.0004). In contrast, BRAF-mutant tumors with microsatellite-stable (MSS) status displayed poorer prognosis despite higher chemotherapy exposure (OR = 7.226, p < 0.001; p = 0.0000). Among EOCRC patients treated with FOLFOX, RTK-RAS alterations were linked to worse outcomes (p = 0.0262). The system also identified ancestry-enriched noncanonical mutations—including CBL, MAPK3, and NF1—with NF1 mutations significantly associated with improved prognosis (p = 1 × 10−5). Conclusions: AI-HOPE-RTK-RAS exemplifies a new class of conversational AI platforms tailored to precision oncology, enabling integrative, real-time analysis of clinically and biologically complex questions. Its ability to uncover both canonical and ancestry-specific patterns in RTK-RAS dysregulation—especially in EOCRC and populations with disproportionate health burdens—underscores its utility in advancing equitable, personalized cancer care. This work demonstrates the translational potential of domain-optimized AI tools to accelerate biomarker discovery, support therapeutic stratification, and democratize access to multi-omic analysis. Full article
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22 pages, 4200 KiB  
Article
Investigation of Personalized Visual Stimuli via Checkerboard Patterns Using Flickering Circles for SSVEP-Based BCI System
by Nannaphat Siribunyaphat, Natjamee Tohkhwan and Yunyong Punsawad
Sensors 2025, 25(15), 4623; https://doi.org/10.3390/s25154623 - 25 Jul 2025
Viewed by 636
Abstract
In this study, we conducted two steady-state visual evoked potential (SSVEP) studies to develop a practical brain–computer interface (BCI) system for communication and control applications. The first study introduces a novel visual stimulus paradigm that combines checkerboard patterns with flickering circles configured in [...] Read more.
In this study, we conducted two steady-state visual evoked potential (SSVEP) studies to develop a practical brain–computer interface (BCI) system for communication and control applications. The first study introduces a novel visual stimulus paradigm that combines checkerboard patterns with flickering circles configured in single-, double-, and triple-layer forms. We tested three flickering frequency conditions: a single fundamental frequency, a combination of the fundamental frequency and its harmonics, and a combination of two fundamental frequencies. The second study utilizes personalized visual stimuli to enhance SSVEP responses. SSVEP detection was performed using power spectral density (PSD) analysis by employing Welch’s method and relative PSD to extract SSVEP features. Commands classification was carried out using a proposed decision rule–based algorithm. The results were compared with those of a conventional checkerboard pattern with flickering squares. The experimental findings indicate that single-layer flickering circle patterns exhibit comparable or improved performance when compared with the conventional stimuli, particularly when customized for individual users. Conversely, the multilayer patterns tended to increase visual fatigue. Furthermore, individualized stimuli achieved a classification accuracy of 90.2% in real-time SSVEP-based BCI systems for six-command generation tasks. The personalized visual stimuli can enhance user experience and system performance, thereby supporting the development of a practical SSVEP-based BCI system. Full article
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17 pages, 2089 KiB  
Article
Analytical Periodic Solutions for Non-Homogenous Integrable Dispersionless Equations Using a Modified Harmonic Balance Method
by Muhammad Irfan Khan, Yiu-Yin Lee and Muhammad Danish Zia
Mathematics 2025, 13(15), 2386; https://doi.org/10.3390/math13152386 - 24 Jul 2025
Viewed by 256
Abstract
In this study, we outline a modified harmonic balance method for solving non-homogenous integrable dispersionless equations and obtaining the corresponding periodic solutions, a research field which shows limited investigation. This study is the first to solve this nonlinear problem, based on a recently [...] Read more.
In this study, we outline a modified harmonic balance method for solving non-homogenous integrable dispersionless equations and obtaining the corresponding periodic solutions, a research field which shows limited investigation. This study is the first to solve this nonlinear problem, based on a recently developed harmonic balance method combined with Vieta’s substitution technique. A set of analytical formulas are generated from the modified harmonic balance method and used to compute the approximate periodic solutions of the dispersionless equations. The main advantage of this method is that the computation effort required in the solution procedure can be smaller. The results of the modified harmonic balance method show reasonable agreement with those obtained using the classic harmonic balance method. Our proposed solution method can decouple the nonlinear algebraic equations generated in the harmonic balance process. We also investigated the effects of various parameters on nonlinear periodic responses and harmonic convergence. Full article
(This article belongs to the Special Issue Modeling and Control in Vibrational and Structural Dynamics)
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20 pages, 4960 KiB  
Article
A Fault Diagnosis Method for Planetary Gearboxes Using an Adaptive Multi-Bandpass Filter, RCMFE, and DOA-LSSVM
by Xin Xia, Aiguo Wang and Haoyu Sun
Symmetry 2025, 17(8), 1179; https://doi.org/10.3390/sym17081179 - 23 Jul 2025
Viewed by 162
Abstract
Effective fault feature extraction and classification methods serve as the foundation for achieving the efficient fault diagnosis of planetary gearboxes. Considering the vibration signals of planetary gearboxes that contain both symmetrical and asymmetrical components, this paper proposes a novel feature extraction method integrating [...] Read more.
Effective fault feature extraction and classification methods serve as the foundation for achieving the efficient fault diagnosis of planetary gearboxes. Considering the vibration signals of planetary gearboxes that contain both symmetrical and asymmetrical components, this paper proposes a novel feature extraction method integrating an adaptive multi-bandpass filter (AMBPF) and refined composite multi-scale fuzzy entropy (RCMFE). And a dream optimization algorithm (DOA)–least squares support vector machine (LSSVM) is also proposed for fault classification. Firstly, the AMBPF is proposed, which can effectively and adaptively separate the meshing frequencies, harmonic frequencies, and their sideband frequency information of the planetary gearbox, and is combined with RCMFE for fault feature extraction. Secondly, the DOA is employed to optimize the parameters of the LSSVM, aiming to enhance its classification efficiency. Finally, the fault diagnosis of the planetary gearbox is achieved by the AMBPF, RCMFE, and DOA-LSSVM. The experimental results demonstrate that the proposed method achieves significantly higher diagnostic efficiency and exhibits superior noise immunity in planetary gearbox fault diagnosis. Full article
(This article belongs to the Special Issue Symmetry in Fault Detection and Diagnosis for Dynamic Systems)
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26 pages, 6051 KiB  
Article
A Novel Sound Coding Strategy for Cochlear Implants Based on Spectral Feature and Temporal Event Extraction
by Behnam Molaee-Ardekani, Rafael Attili Chiea, Yue Zhang, Julian Felding, Aswin Adris Wijetillake, Peter T. Johannesen, Enrique A. Lopez-Poveda and Manuel Segovia-Martínez
Technologies 2025, 13(8), 318; https://doi.org/10.3390/technologies13080318 - 23 Jul 2025
Viewed by 329
Abstract
This paper presents a novel cochlear implant (CI) sound coding strategy called Spectral Feature Extraction (SFE). The SFE is a novel Fast Fourier Transform (FFT)-based Continuous Interleaved Sampling (CIS) strategy that provides less-smeared spectral cues to CI patients compared to Crystalis, a predecessor [...] Read more.
This paper presents a novel cochlear implant (CI) sound coding strategy called Spectral Feature Extraction (SFE). The SFE is a novel Fast Fourier Transform (FFT)-based Continuous Interleaved Sampling (CIS) strategy that provides less-smeared spectral cues to CI patients compared to Crystalis, a predecessor strategy used in Oticon Medical devices. The study also explores how the SFE can be enhanced into a Temporal Fine Structure (TFS)-based strategy named Spectral Event Extraction (SEE), combining spectral sharpness with temporal cues. Background/Objectives: Many CI recipients understand speech in quiet settings but struggle with music and complex environments, increasing cognitive effort. De-smearing the power spectrum and extracting spectral peak features can reduce this load. The SFE targets feature extraction from spectral peaks, while the SEE enhances TFS-based coding by tracking these features across frames. Methods: The SFE strategy extracts spectral peaks and models them with synthetic pure tone spectra characterized by instantaneous frequency, phase, energy, and peak resemblance. This deblurs input peaks by estimating their center frequency. In SEE, synthetic peaks are tracked across frames to yield reliable temporal cues (e.g., zero-crossings) aligned with stimulation pulses. Strategy characteristics are analyzed using electrodograms. Results: A flexible Frequency Allocation Map (FAM) can be applied to both SFE and SEE strategies without being limited by FFT bandwidth constraints. Electrodograms of Crystalis and SFE strategies showed that SFE reduces spectral blurring and provides detailed temporal information of harmonics in speech and music. Conclusions: SFE and SEE are expected to enhance speech understanding, lower listening effort, and improve temporal feature coding. These strategies could benefit CI users, especially in challenging acoustic environments. Full article
(This article belongs to the Special Issue The Challenges and Prospects in Cochlear Implantation)
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35 pages, 1752 KiB  
Review
Recent Advances in Biodegradable Magnesium Alloys for Medical Implants: Evolution, Innovations, and Clinical Translation
by Mykyta Aikin, Vadim Shalomeev, Volodymyr Kukhar, Andrii Kostryzhev, Ihor Kuziev, Viktoriia Kulynych, Oleksandr Dykha, Volodymyr Dytyniuk, Oleksandr Shapoval, Alvydas Zagorskis, Vadym Burko, Olha Khliestova, Viacheslav Titov and Oleksandr Hrushko
Crystals 2025, 15(8), 671; https://doi.org/10.3390/cryst15080671 - 23 Jul 2025
Viewed by 593
Abstract
Biodegradable magnesium alloys have emerged as promising alternatives to permanent metallic implants due to their unique combination of mechanical compatibility with bone and complete resorption, addressing the persistent issues of stress shielding and secondary removal surgeries. This review critically examines the historical development [...] Read more.
Biodegradable magnesium alloys have emerged as promising alternatives to permanent metallic implants due to their unique combination of mechanical compatibility with bone and complete resorption, addressing the persistent issues of stress shielding and secondary removal surgeries. This review critically examines the historical development of magnesium-based biomaterials, highlighting advances in alloy design, manufacturing processes, and surface engineering that now enable tailored degradation and improved clinical performance. Drawing on recent clinical and preclinical studies, we summarize improvements in corrosion resistance, mechanical properties, and biocompatibility that have supported the clinical translation of magnesium alloys across a variety of orthopedic and emerging medical applications. However, challenges remain, including unpredictable in vivo degradation kinetics, limited long-term safety data, lack of standardized testing protocols, and ongoing regulatory uncertainties. We conclude that while magnesium-based biomaterials have advanced from experimental concepts to clinically validated solutions, further progress in personalized degradation control, real-time monitoring, and harmonized regulatory frameworks is needed to fully realize their transformative clinical potential. Full article
(This article belongs to the Special Issue Development of Light Alloys and Their Applications)
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26 pages, 2204 KiB  
Article
A Qualitative Methodology for Identifying Governance Challenges and Advancements in Positive Energy District Labs
by Silvia Soutullo, Oscar Seco, María Nuria Sánchez, Ricardo Lima, Fabio Maria Montagnino, Gloria Pignatta, Ghazal Etminan, Viktor Bukovszki, Touraj Ashrafian, Maria Beatrice Andreucci and Daniele Vettorato
Urban Sci. 2025, 9(8), 288; https://doi.org/10.3390/urbansci9080288 - 23 Jul 2025
Viewed by 355
Abstract
Governance challenges, success factors, and stakeholder dynamics are central to the implementation of Positive Energy District (PED) Labs, which aim to develop energy-positive and sustainable urban areas. In this paper, a qualitative analysis combining expert surveys, participatory workshops with practitioners from the COST [...] Read more.
Governance challenges, success factors, and stakeholder dynamics are central to the implementation of Positive Energy District (PED) Labs, which aim to develop energy-positive and sustainable urban areas. In this paper, a qualitative analysis combining expert surveys, participatory workshops with practitioners from the COST Action PED-EU-NET network, and comparative case studies across Europe identifies key barriers, drivers, and stakeholder roles throughout the implementation process. Findings reveal that fragmented regulations, social inertia, and limited financial mechanisms are the main barriers to PED Lab development, while climate change mitigation goals, strong local networks, and supportive policy frameworks are critical drivers. The analysis maps stakeholder engagement across six development phases, showing how leadership shifts between governments, industry, planners, and local communities. PED Labs require intangible assets such as inclusive governance frameworks, education, and trust-building in the early phases, while tangible infrastructures become more relevant in later stages. The conclusions emphasize that robust, inclusive governance is not merely supportive but a key driver of PED Lab success. Adaptive planning, participatory decision-making, and digital coordination tools are essential for overcoming systemic barriers. Scaling PED Labs effectively requires regulatory harmonization and the integration of social and technological innovation to accelerate the transition toward energy-positive, climate-resilient cities. Full article
(This article belongs to the Collection Urban Agenda)
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22 pages, 4664 KiB  
Article
Aerial Image-Based Crop Row Detection and Weed Pressure Mapping Method
by László Moldvai, Péter Ákos Mesterházi, Gergely Teschner and Anikó Nyéki
Agronomy 2025, 15(8), 1762; https://doi.org/10.3390/agronomy15081762 - 23 Jul 2025
Viewed by 264
Abstract
Accurate crop row detection is crucial for determining weed pressure (weeds item per square meter). However, this task is complicated by the similarity between crops and weeds, the presence of missing plants within rows, and the varying growth stages of both. Our hypothesis [...] Read more.
Accurate crop row detection is crucial for determining weed pressure (weeds item per square meter). However, this task is complicated by the similarity between crops and weeds, the presence of missing plants within rows, and the varying growth stages of both. Our hypothesis was that in drone imagery captured at altitudes of 20–30 m—where individual plant details are not discernible—weed presence among crops can be statistically detected, allowing for the generation of a weed distribution map. This study proposes a computer vision detection method using images captured by unmanned aerial vehicles (UAVs) consisting of six main phases. The method was tested on 208 images. The algorithm performs well under normal conditions; however, when the weed density is too high, it fails to detect the row direction properly and begins processing misleading data. To investigate these cases, 120 artificial datasets were created with varying parameters, and the scenarios were analyzed. It was found that a rate variable—in-row concentration ratio (IRCR)—can be used to determine whether the result is valid (usable) or invalid (to be discarded). The F1 score is a metric combining precision and recall using a harmonic mean, where “1” indicates that precision and recall are equally weighted, i.e., β = 1 in the general Fβ formula. In the case of moderate weed infestation, where 678 crop plants and 600 weeds were present, the algorithm achieved an F1 score of 86.32% in plant classification, even with a 4% row disturbance level. Furthermore, IRCR also indicates the level of weed pressure in the area. The correlation between the ground truth weed-to-crop ratio and the weed/crop classification rate produced by the algorithm is 98–99%. As a result, the algorithm is capable of filtering out heavily infested areas that require full weed control and capable of generating weed density maps on other cases to support precision weed management. Full article
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26 pages, 55836 KiB  
Article
Experimental Acoustic Investigation of Rotor Noise Directivity and Decay in Multiple Configurations
by Giovanni Fasulo, Giosuè Longobardo, Fabrizio De Gregorio and Mattia Barbarino
Aerospace 2025, 12(7), 647; https://doi.org/10.3390/aerospace12070647 - 21 Jul 2025
Viewed by 235
Abstract
In the framework of the MATIM project, an acoustic test campaign was conducted on a platform derived from a commercial-class quadcopter within the CIRA semi-anechoic chamber. A dedicated rotor rig allowed systematic measurements of thrust, torque, and shaft speed together with near- and [...] Read more.
In the framework of the MATIM project, an acoustic test campaign was conducted on a platform derived from a commercial-class quadcopter within the CIRA semi-anechoic chamber. A dedicated rotor rig allowed systematic measurements of thrust, torque, and shaft speed together with near- and far-field noise using ten calibrated 1/2-inch precision microphones. Three configurations were examined: an isolated rotor, the same rotor mounted on an aluminium quadcopter plate, and the full four-rotor assembly. The resulting data set, acquired over 3000–8000 rpm, documents the azimuthal directivity and radial decay of tonal and broadband noise while separating motor, propeller, and installation contributions. Analysis shows that a nearby rigid plate scatters part of the sound field towards frontal and oblique observers and produces a shielding effect in the rotor plane. The combined operation of four rotors further redistributes energy and broadens blade-passing frequency harmonics. The database is intended as a benchmark for aeroacoustics codes and for the development of reduced-order models. Full article
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32 pages, 2529 KiB  
Article
Cloud Adoption in the Digital Era: An Interpretable Machine Learning Analysis of National Readiness and Structural Disparities Across the EU
by Cristiana Tudor, Margareta Florescu, Persefoni Polychronidou, Pavlos Stamatiou, Vasileios Vlachos and Konstadina Kasabali
Appl. Sci. 2025, 15(14), 8019; https://doi.org/10.3390/app15148019 - 18 Jul 2025
Viewed by 269
Abstract
As digital transformation accelerates across Europe, cloud computing plays an increasingly central role in modernizing public services and private enterprises. Yet adoption rates vary markedly among EU member states, reflecting deeper structural differences in digital capacity. This study employs explainable machine learning to [...] Read more.
As digital transformation accelerates across Europe, cloud computing plays an increasingly central role in modernizing public services and private enterprises. Yet adoption rates vary markedly among EU member states, reflecting deeper structural differences in digital capacity. This study employs explainable machine learning to uncover the drivers of national cloud adoption across 27 EU countries using harmonized panel datasets spanning 2014–2021 and 2014–2024. A methodological pipeline combining Random Forests (RF), XGBoost, Support Vector Machines (SVM), and Elastic Net regression is implemented, with model tuning conducted via nested cross-validation. Among individual models, Elastic Net and SVM delivered superior predictive performance, while a stacked ensemble achieved the best overall accuracy (MAE = 0.214, R2 = 0.948). The most interpretable model, a standardized RF with country fixed effects, attained MAE = 0.321, and R2 = 0.864, making it well-suited for policy analysis. Variable importance analysis reveals that the density of ICT specialists is the strongest predictor of adoption, followed by broadband access and higher education. Fixed-effect modeling confirms significant national heterogeneity, with countries like Finland and Luxembourg consistently leading adoption, while Bulgaria and Romania exhibit structural barriers. Partial dependence and SHAP analyses reveal nonlinear complementarities between digital skills and infrastructure. A hierarchical clustering of countries reveals three distinct digital maturity profiles, offering tailored policy pathways. These results directly support the EU Digital Decade’s strategic targets and provide actionable insights for advancing inclusive and resilient digital transformation across the Union. Full article
(This article belongs to the Special Issue Advanced Technologies Applied in Digital Media Era)
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