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Search Results (816)

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21 pages, 2522 KB  
Article
A Reinforcement Learning-Based Adaptive Grey Wolf Optimizer for Simultaneous Arrival in Manned/Unmanned Aerial Vehicle Dynamic Cooperative Trajectory Planning
by Wei Jia, Lei Lv, Ruizhi Duan, Tianye Sun and Wei Sun
Drones 2025, 9(10), 723; https://doi.org/10.3390/drones9100723 - 17 Oct 2025
Abstract
Addressing the challenge of high-precision time-coordinated path planning for manned and unmanned aerial vehicle (UAV) clusters operating in complex dynamic environments during missions like high-level autonomous coordination, this paper proposes a reinforcement learning-based Adaptive Grey Wolf Optimizer (RL-GWO) method. We formulate a comprehensive [...] Read more.
Addressing the challenge of high-precision time-coordinated path planning for manned and unmanned aerial vehicle (UAV) clusters operating in complex dynamic environments during missions like high-level autonomous coordination, this paper proposes a reinforcement learning-based Adaptive Grey Wolf Optimizer (RL-GWO) method. We formulate a comprehensive multi-objective cost function integrating total flight distance, mission time, time synchronization error, and collision penalties. To solve this model, we design multiple improved GWO strategies and employ a Q-Learning framework for adaptive strategy selection. The RL-GWO algorithm is embedded within a dual-layer “global planning + dynamic replanning” framework. Simulation results demonstrate excellent convergence and robustness, achieving second-level time synchronization accuracy while satisfying complex constraints. In dynamic scenarios, the method rapidly generates safe evasion paths while maintaining cluster coordination, validating its practical value for heterogeneous UAV operations. Full article
(This article belongs to the Special Issue Path Planning, Trajectory Tracking and Guidance for UAVs: 3rd Edition)
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14 pages, 3946 KB  
Article
A Kinematics-Constrained Grid-Based Path Planning Algorithm for Autonomous Parking
by Kyungsub Sim, Junho Kim and Juhui Gim
Appl. Sci. 2025, 15(20), 11138; https://doi.org/10.3390/app152011138 - 17 Oct 2025
Viewed by 19
Abstract
This paper presents a kinematics-constrained grid-based path planning algorithm that generates real-time, safe, and executable trajectories, thereby enhancing the performance and reliability of autonomous vehicle parking systems. The grid resolution adapts to the minimum turning radius and steering limits, ensuring feasible motion primitives. [...] Read more.
This paper presents a kinematics-constrained grid-based path planning algorithm that generates real-time, safe, and executable trajectories, thereby enhancing the performance and reliability of autonomous vehicle parking systems. The grid resolution adapts to the minimum turning radius and steering limits, ensuring feasible motion primitives. The cost function integrates path efficiency, direction-switching penalties, and collision risk to ensure smooth and feasible maneuvers. A cubic spline refinement produces curvature-continuous trajectories suitable for vehicle execution. Simulation and experimental results demonstrate that the proposed method achieves collision-free and curvature-bounded paths with significantly reduced computation time and improved maneuver smoothness compared with conventional A* and Hybrid A*. In both structured and dynamic parking environments, the planner consistently maintained safe clearance and stable tracking performance under variations in vehicle geometry and velocity. These results confirm the robustness and real-time feasibility of the proposed approach, effectively unifying kinematic feasibility, safety, and computational efficiency for practical autonomous parking systems. Full article
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30 pages, 46947 KB  
Article
Safety-Aware Pre-Flight Trajectory Planning for Urban UAVs with Contingency Plans for Mechanical and GPS Failure Scenarios
by Amin Almozel, Ania Adil and Eric Feron
Drones 2025, 9(10), 708; https://doi.org/10.3390/drones9100708 - 14 Oct 2025
Viewed by 224
Abstract
Urban drone operations are exposed to unpredictable risks, including engine failure and deliberate signal interference. A recent and ongoing disruption in Jeddah, Saudi Arabia, has seen widespread GPS spoofing that misleads devices by hundreds of kilometers, illustrating how fragile unmanned aerial vehicle (UAV) [...] Read more.
Urban drone operations are exposed to unpredictable risks, including engine failure and deliberate signal interference. A recent and ongoing disruption in Jeddah, Saudi Arabia, has seen widespread GPS spoofing that misleads devices by hundreds of kilometers, illustrating how fragile unmanned aerial vehicle (UAV) operations can become when over-reliant on GNSS-based navigation. Such disruptions highlight the urgent need for contingency planning in drone traffic management systems. This study introduces a safety-aware pre-flight path planning framework that proactively integrates emergency landing and GPS fallback options into UAV trajectory pre-flight planning. The planner considers proximity to predesignated emergency landing zones, communication coverage, and airspace restrictions, enabling UAVs to safely complete their operations. The approach is evaluated across realistic mission profiles such as delivery, inspection, and surveillance. Results show that the planner successfully maintains mission feasibility while embedding emergency readiness throughout each flight. This work contributes toward safer, failure-resilient drone integration in urban airspace, ensuring that contingency plans are proactively incorporated into path planning before the failure even occurs. Full article
(This article belongs to the Section Innovative Urban Mobility)
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26 pages, 6270 KB  
Article
Autonomous Navigation Approach for Complex Scenarios Based on Layered Terrain Analysis and Nonlinear Model
by Wenhe Chen, Leer Hua, Shuonan Shen, Yue Wang, Qi Pu and Xundiao Ma
Information 2025, 16(10), 896; https://doi.org/10.3390/info16100896 - 14 Oct 2025
Viewed by 254
Abstract
In complex scenarios, such as industrial parks and underground parking lots, efficient and safe autonomous navigation is essential for driverless operation and automatic parking. However, conventional modular navigation methods, especially the A* algorithm, suffer from excessive node traversal and short paths that bring [...] Read more.
In complex scenarios, such as industrial parks and underground parking lots, efficient and safe autonomous navigation is essential for driverless operation and automatic parking. However, conventional modular navigation methods, especially the A* algorithm, suffer from excessive node traversal and short paths that bring vehicles dangerously close to obstacles. To address these issues, we propose an autonomous navigation approach based on a layered terrain cost map and a nonlinear predictive control model, which ensures real-time performance, safety, and reduced computational cost. The global planner applies a two-stage A* strategy guided by the hierarchical terrain cost map, improving efficiency and obstacle avoidance, while the local planner combines linear interpolation with nonlinear model predictive control to adaptively adjust the vehicle speed under varying terrain conditions. Experiments conducted in simulated and real underground parking scenarios demonstrate that the proposed method significantly improves the computational efficiency and navigation safety, outperforming the traditional A* algorithm and other baseline approaches in overall performance. Full article
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20 pages, 7865 KB  
Article
Study on Development of Hydrogen Peroxide Generation Reactor with Pin-to-Water Atmospheric Discharges
by Sung-Young Yoon, Eun Jeong Hong, Junghyun Lim, Seungil Park, Sangheum Eom, Seong Bong Kim and Seungmin Ryu
Plasma 2025, 8(4), 41; https://doi.org/10.3390/plasma8040041 - 14 Oct 2025
Viewed by 169
Abstract
We present an experimentally validated, engineering-oriented framework for the design and operation of pin-to-water (PTW) atmospheric discharges to produce hydrogen peroxide (H2O2) on demand. Motivated by industrial needs for safe, point-of-use oxidant supply, we combine time-resolved diagnostics (FTIR, OES), [...] Read more.
We present an experimentally validated, engineering-oriented framework for the design and operation of pin-to-water (PTW) atmospheric discharges to produce hydrogen peroxide (H2O2) on demand. Motivated by industrial needs for safe, point-of-use oxidant supply, we combine time-resolved diagnostics (FTIR, OES), liquid-phase analysis (ion chromatography, pH, conductivity), and coupled plasma-chemistry/fluid simulations to link plasma state to aqueous H2O2 yield. Under the tested conditions (14.3 kHz, 0.2 kW; electrode to quartz wall distance 12–14 mm; coolant setpoints 0–40 °C), H2O2 concentration follows a reproducible non-monotonic trajectory: rapid accumulation during the early treatment (typical peak at ~15–25 min), followed by decline with continued operation. The decline coincides with a robust vibrational-temperature (Tvib) threshold near ~4900 K measured from N2 emission, and with concurrent NOX accumulation and bulk acidification. Global chemistry modeling and Fluent flow fields reproduce the observed trend and show that both vibrational excitation (kinetics) and convective transport (mass/heat transfer) determine the productive time window. Based on these results, we formulate practical design rules—electrode gap (power density), discharge current control, thermal/flow management, water quality, and OES-based Tvib monitoring with an automated stop rule—that maximize H2O2 yield while avoiding NOX-dominated suppression. The study provides a clear path for transforming mechanistic plasma insights into deployable, industrial H2O2 generator designs. Full article
(This article belongs to the Special Issue Feature Papers in Plasma Sciences 2025)
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17 pages, 2195 KB  
Article
Collision-Free Robot Path Planning by Integrating DRL with Noise Layers and MPC
by Xinzhan Hong, Qieshi Zhang, Yexing Yang, Tianqi Zhao, Zhenyu Xu, Tichao Wang and Jing Ji
Sensors 2025, 25(20), 6263; https://doi.org/10.3390/s25206263 - 10 Oct 2025
Viewed by 423
Abstract
With the rapid advancement of Autonomous Mobile Robots (AMRs) in industrial automation and intelligent logistics, achieving efficient and safe path planning in dynamic environments has become a critical challenge. These environments require robots to perceive complex scenarios and adapt their motion strategies accordingly, [...] Read more.
With the rapid advancement of Autonomous Mobile Robots (AMRs) in industrial automation and intelligent logistics, achieving efficient and safe path planning in dynamic environments has become a critical challenge. These environments require robots to perceive complex scenarios and adapt their motion strategies accordingly, often under real-time constraints. Existing methods frequently struggle to balance efficiency, responsiveness, and safety, especially in the presence of continuously changing dynamic obstacles. While Model Predictive Control (MPC) and Deep Reinforcement Learning (DRL) have each shown promise in this domain, they also face limitations when applied individually—such as high computational demands or insufficient environmental exploration. To address these challenges, we propose a hybrid path planning framework that integrates an optimized DRL algorithm with MPC. We replace the Actor’s output with a learnable noisy linear layer whose mean and scale parameters are optimized jointly with the policy via backpropagation, thereby enhancing exploration while preserving training stability. TD3 produces stepwise control commands that evolve into a short-horizon reference trajectory, while MPC refines this trajectory through constraint-aware optimization to ensure timely obstacle avoidance. This complementary process combines TD3′s learning-based adaptability with MPC’s reliable local feasibility. Extensive experiments conducted in environments with varying obstacle dynamics and densities demonstrate that the proposed method significantly improves obstacle avoidance success rate, trajectory smoothness, and path accuracy compared to traditional MPC, standalone DRL, and other hybrid approaches, offering a robust and efficient solution for autonomous navigation in complex scenarios. Full article
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24 pages, 1582 KB  
Article
Future Internet Applications in Healthcare: Big Data-Driven Fraud Detection with Machine Learning
by Konstantinos P. Fourkiotis and Athanasios Tsadiras
Future Internet 2025, 17(10), 460; https://doi.org/10.3390/fi17100460 - 8 Oct 2025
Viewed by 377
Abstract
Hospital fraud detection has often relied on periodic audits that miss evolving, internet-mediated patterns in electronic claims. An artificial intelligence and machine learning pipeline is being developed that is leakage-safe, imbalance aware, and aligned with operational capacity for large healthcare datasets. The preprocessing [...] Read more.
Hospital fraud detection has often relied on periodic audits that miss evolving, internet-mediated patterns in electronic claims. An artificial intelligence and machine learning pipeline is being developed that is leakage-safe, imbalance aware, and aligned with operational capacity for large healthcare datasets. The preprocessing stack integrates four tables, engineers 13 features, applies imputation, categorical encoding, Power transformation, Boruta selection, and denoising autoencoder representations, with class balancing via SMOTE-ENN evaluated inside cross-validation folds. Eight algorithms are compared under a fraud-oriented composite productivity index that weighs recall, precision, MCC, F1, ROC-AUC, and G-Mean, with per-fold threshold calibration and explicit reporting of Type I and Type II errors. Multilayer perceptron attains the highest composite index, while CatBoost offers the strongest control of false positives with high accuracy. SMOTE-ENN provides limited gains once representations regularize class geometry. The calibrated scores support prepayment triage, postpayment audit, and provider-level profiling, linking alert volume to expected recovery and protecting investigator workload. Situated in the Future Internet context, this work targets internet-mediated claim flows and web-accessible provider registries. Governance procedures for drift monitoring, fairness assessment, and change control complete an internet-ready deployment path. The results indicate that disciplined preprocessing and evaluation, more than classifier choice alone, translate AI improvements into measurable economic value and sustainable fraud prevention in digital health ecosystems. Full article
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15 pages, 1323 KB  
Article
A Hybrid Ant Colony Optimization and Dynamic Window Method for Real-Time Navigation of USVs
by Yuquan Xue, Liming Wang, Bi He, Shuo Yang, Yonghui Zhao, Xing Xu, Jiaxin Hou and Longmei Li
Sensors 2025, 25(19), 6181; https://doi.org/10.3390/s25196181 - 6 Oct 2025
Viewed by 396
Abstract
Unmanned surface vehicles (USVs) rely on multi-sensor perception, such as radar, LiDAR, GPS, and vision, to ensure safe and efficient navigation in complex maritime environments. Traditional ant colony optimization (ACO) for path planning, however, suffers from premature convergence, slow adaptation, and poor smoothness [...] Read more.
Unmanned surface vehicles (USVs) rely on multi-sensor perception, such as radar, LiDAR, GPS, and vision, to ensure safe and efficient navigation in complex maritime environments. Traditional ant colony optimization (ACO) for path planning, however, suffers from premature convergence, slow adaptation, and poor smoothness in cluttered waters, while the dynamic window approach (DWA) without global guidance can become trapped in local obstacle configurations. This paper presents a sensor-oriented hybrid method that couples an improved ACO for global route planning with an enhanced DWA for local, real-time obstacle avoidance. In the global stage, the ACO state–transition rule integrates path length, obstacle clearance, and trajectory smoothness heuristics, while a cosine-annealed schedule adaptively balances exploration and exploitation. Pheromone updating combines local and global mechanisms under bounded limits, with a stagnation detector to restore diversity. In the local stage, the DWA cost function is redesigned under USV kinematics to integrate velocity adaptability, trajectory smoothness, and goal-deviation, using obstacle data that would typically originate from onboard sensors. Simulation studies, where obstacle maps emulate sensor-detected environments, show that the proposed method achieves shorter paths, faster convergence, smoother trajectories, larger safety margins, and higher success rates against dynamic obstacles compared with standalone ACO or DWA. These results demonstrate the method’s potential for sensor-based, real-time USV navigation and collision avoidance in complex maritime scenarios. Full article
(This article belongs to the Section Sensors and Robotics)
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17 pages, 286 KB  
Review
Deep Learning Image Processing Models in Dermatopathology
by Apoorva Mehta, Mateen Motavaf, Danyal Raza, Neil Jairath, Akshay Pulavarty, Ziyang Xu, Michael A. Occidental, Alejandro A. Gru and Alexandra Flamm
Diagnostics 2025, 15(19), 2517; https://doi.org/10.3390/diagnostics15192517 - 4 Oct 2025
Viewed by 452
Abstract
Dermatopathology has rapidly advanced due to the implementation of deep learning models and artificial intelligence (AI). From convolutional neural networks (CNNs) to transformer-based foundation models, these systems are now capable of accurate whole-slide analysis and multimodal integration. This review synthesizes the most recent [...] Read more.
Dermatopathology has rapidly advanced due to the implementation of deep learning models and artificial intelligence (AI). From convolutional neural networks (CNNs) to transformer-based foundation models, these systems are now capable of accurate whole-slide analysis and multimodal integration. This review synthesizes the most recent advents of deep-learning architecture and synthesizes its evolution from first-generation CNNs to hybrid CNN-transformer systems to large-scale foundational models such as Paige’s PanDerm AI and Virchow. Herein, we examine performance benchmarks from real-world deployments of major dermatopathology deep learning models (DermAI, PathAssist Derm), as well as emerging next-generation models still under research and development. We assess barriers to clinical workflow adoption such as dataset bias, AI interpretability, and government regulation. Further, we discuss potential future research directions and emphasize the need for diverse, prospectively curated datasets, explainability frameworks for trust in AI, and rigorous compliance to Good Machine-Learning-Practice (GMLP) to achieve safe and scalable deep learning dermatopathology models that can fully integrate into clinical workflows. Full article
(This article belongs to the Special Issue Artificial Intelligence in Skin Disorders 2025)
16 pages, 2918 KB  
Article
Surface Engineering of Natural Killer Cells with Lipid-Based Antibody Capture Platform for Targeted Chemoimmunotherapy
by Su Yeon Lim, Yeongbeom Kim, Hongbin Kim, Seungmin Han, Jina Yun, Hyun-Ouk Kim, Suk-Jin Ha, Sehyun Chae, Young-Wook Won and Kwang Suk Lim
Pharmaceutics 2025, 17(10), 1285; https://doi.org/10.3390/pharmaceutics17101285 - 1 Oct 2025
Viewed by 469
Abstract
Next-generation cancer immunotherapy increasingly combines tumor-targeting antibodies or antibody–drug conjugates (ADCs) with immune effector cells to enhance therapeutic precision. However, many existing approaches rely on genetic modification or complex manufacturing, limiting their clinical scalability and rapid deployment. To address this issue, we developed [...] Read more.
Next-generation cancer immunotherapy increasingly combines tumor-targeting antibodies or antibody–drug conjugates (ADCs) with immune effector cells to enhance therapeutic precision. However, many existing approaches rely on genetic modification or complex manufacturing, limiting their clinical scalability and rapid deployment. To address this issue, we developed an antibody capture protein (ACP)-based surface engineering platform that enables the rapid, reversible, and non-genetic functionalization of NK cells with therapeutic antibodies or ADCs. This approach uses a DMPE-PEG-lipid conjugate to anchor thiolated protein A (ACP) to the NK cell membrane via hydrophobic insertion, thereby stably and selectively binding to the Fc region of IgG molecules. Using this strategy, we developed ACP-modified NK cells (AC-NKs) that can selectively capture therapeutic antibodies (trastuzumab (TZ), trastuzumab-emtansine (T-DM1), and sacituzumab (SZ)) pre-bound to each target antigen on tumor cells and induce antigen-specific cytotoxic responses. The resulting AC-NKs exhibited enhanced tumor recognition and cytotoxicity against HER2-positive and Trop-2-positive cancer cells in vitro. Compared with conventional combination therapies, AC-NKs enhanced immune activation, as demonstrated by effective delivery of cytotoxic agents, enhanced cancer cell engagement, and upregulation of CD107a expression. Notably, the system supports multiple antigen targeting and tunable antibody loading, enabling adaptation to tumor heterogeneity and resistant phenotypes. This platform might also provide a simple, scalable, and safe method for rapidly developing programmable immune cell therapies without genetic modification. Its versatility supports multi-antigen targeting and broad applicability across NK and T cell therapies, offering a promising path toward personalized, off-the-shelf chemoimmunotherapy. Full article
(This article belongs to the Special Issue Advanced Drug Delivery Systems for Targeted Immunotherapy)
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32 pages, 2032 KB  
Article
Stochastic Path Planning with Obstacle Avoidance for UAVs Using Covariance Control
by Alessandro Garzelli, Boris Benedikter, Alessandro Zavoli, José Ramiro Martínez de Dios, Alejandro Suarez and Anibal Ollero
Appl. Sci. 2025, 15(19), 10469; https://doi.org/10.3390/app151910469 - 27 Sep 2025
Viewed by 378
Abstract
Unmanned aerial vehicles (UAVs) operating in uncertain environments must plan safe and efficient trajectories while avoiding obstacles. This work addresses this challenge by formulating UAV path planning as a stochastic optimal control problem using covariance control. The objective is to generate a closed-loop [...] Read more.
Unmanned aerial vehicles (UAVs) operating in uncertain environments must plan safe and efficient trajectories while avoiding obstacles. This work addresses this challenge by formulating UAV path planning as a stochastic optimal control problem using covariance control. The objective is to generate a closed-loop guidance policy that steers both the mean and covariance of the UAV’s state toward a desired target distribution while ensuring probabilistic collision avoidance with ellipsoidal obstacles. The stochastic problem is convexified and reformulated as a sequence of deterministic optimization problems, enabling efficient computation even from coarse initial guesses. Simulation results demonstrate that the proposed method successfully produces robust trajectories and feedback policies that satisfy chance constraints on obstacle avoidance and reach the target with prescribed statistical characteristics. Full article
(This article belongs to the Special Issue Novel Approaches and Trends in Aerospace Control Systems)
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11 pages, 2318 KB  
Brief Report
A Dual-Purpose Approach for an Anti-Emetic NK1R Antagonist as a Chemosensitizer and Cardioprotectant in a Preclinical Model of Triple-Negative Breast Cancer
by Miguel Muñoz, Rafael Coveñas, Younus Zuberi, Zara Italia, Tan Hoang, Zal Italia and Prema Robinson
Int. J. Mol. Sci. 2025, 26(19), 9353; https://doi.org/10.3390/ijms26199353 - 25 Sep 2025
Viewed by 374
Abstract
Doxorubicin (Dox) is considered one of the most effective treatments for triple-negative breast cancer (TNBC); however, it can cause limited efficacy, recurrence/chemoresistance, and cardiotoxicity. Using a murine preclinical MDA-MB-231 TNBC model, we determined that targeting the substance P/neurokinin-1 receptor signaling axis can increase [...] Read more.
Doxorubicin (Dox) is considered one of the most effective treatments for triple-negative breast cancer (TNBC); however, it can cause limited efficacy, recurrence/chemoresistance, and cardiotoxicity. Using a murine preclinical MDA-MB-231 TNBC model, we determined that targeting the substance P/neurokinin-1 receptor signaling axis can increase efficacy of the standard-of-care treatment currently used for TNBC, i.e., doxorubicin (Dox), while also attenuating Dox-induced, cardiotoxicity in TNBC. The in vivo studies outlined in this manuscript validate aprepitant (AP), a neurokinin-1 receptor antagonist, as a safe, dual-purpose chemosensitizer and cardioprotectant. These studies provide preclinical evidence supporting further evaluation of a continuous daily AP regimen in TNBC models in combination with Dox, laying the groundwork for future investigations into its safety, dosing, and potential clinical application. Because AP is already FDA-approved for single-dose anti-emetic use, repurposing it for chronic administration offers a rapid path to clinical translation, with the potential to redefine chemotherapy paradigms and tangibly improve survival and quality of life in TNBC. Full article
(This article belongs to the Section Molecular Oncology)
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28 pages, 20909 KB  
Article
UAV Path Planning in Threat Environment: A*-APF Algorithm for Spatio-Temporal Grid Optimization
by Longhao Liu, Le Ru, Wenfei Wang, Hailong Xi, Rui Zhu, Shiliang Li and Zhenghao Zhang
Drones 2025, 9(9), 661; https://doi.org/10.3390/drones9090661 - 22 Sep 2025
Cited by 1 | Viewed by 586 | Correction
Abstract
To address low threat avoidance efficiency and poor global path adaptability in UAV path planning under threatening environments, this paper proposes a hybrid A*-Artificial Potential Field (APF) path planning method based on spatio-temporal grid optimization. First, a new global fine-grained spatio-temporal grid system [...] Read more.
To address low threat avoidance efficiency and poor global path adaptability in UAV path planning under threatening environments, this paper proposes a hybrid A*-Artificial Potential Field (APF) path planning method based on spatio-temporal grid optimization. First, a new global fine-grained spatio-temporal grid system is developed by integrating advantages of GeoSOT binary encoding and BeiDou grid location code subdivision rules, enabling unified modeling of complex spatio-temporal environments. Ground threat and maze scenarios are constructed for verification. Second, traditional A* and APF algorithms are improved: the A* algorithm is enhanced with threat costs, dynamic neighborhood search, and local backtrack mechanisms to address low efficiency and incompatibility with threat avoidance; the APF algorithm is optimized with a dual gravitational field collaboration mechanism and distance-parameter-based repulsive field model to overcome local minima and unreachable goals. Finally, a sliding window-driven path association model achieves seamless collaboration between global and local planning. Experimental results show the proposed method outperforms traditional algorithms in comprehensive performance, with the improved A* algorithm excelling in path length, computation time, threat value, and search nodes, and the improved APF algorithm achieving complete safe obstacle avoidance in dynamic environments. The collaborative mechanism effectively handles complex scenarios. Full article
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33 pages, 7053 KB  
Article
Simulation Study of Gas Cooling for Aero-Engine Borescope Probes
by Lu Jia, Hao Zeng, Rui Xi, Jingbo Peng and Xinyao Hou
Aerospace 2025, 12(9), 852; https://doi.org/10.3390/aerospace12090852 - 21 Sep 2025
Viewed by 399
Abstract
After an aero-engine shuts down, the high temperature within the core flow path prevents conventional borescope probes from performing immediate internal inspections due to their limited thermal resistance, thereby constraining rapid turnaround capabilities for aircraft. To address this challenge, this study proposes an [...] Read more.
After an aero-engine shuts down, the high temperature within the core flow path prevents conventional borescope probes from performing immediate internal inspections due to their limited thermal resistance, thereby constraining rapid turnaround capabilities for aircraft. To address this challenge, this study proposes an active cooling strategy using coolant flow to keep the probe within a safe temperature range. Three cooling structures incorporating pressure-drop modules—annular, annular-slit, and round-hole configurations—were designed and numerically investigated to assess the effects of geometric parameters and coolant properties (temperature, pressure, nitrogen mixing ratio) on cooling performance. The results demonstrate that the round-hole structure with a 1.0 mm diameter achieves optimal cooling, maintaining an average probe mirror temperature of 286.2 K under coolant conditions of 285 K and 0.5 MPa. Cooling efficiency exhibits a strong linear negative correlation with coolant temperature, while its relationship with pressure is highly structure-dependent. Nitrogen doping significantly improves the heat transfer capacity of the coolant. The implemented three-stage pressure-drop module performs consistently, with the pressure loss per stage determined solely by the inlet pressure. This study provides valuable insights and a theoretical foundation for the design of high-temperature-resistant borescope equipment capable of operating in the harsh environments of aero-engines. Full article
(This article belongs to the Section Aeronautics)
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40 pages, 1778 KB  
Review
Smart Routing for Sustainable Shipping: A Review of Trajectory Optimization Approaches in Waterborne Transport
by Yevgeniy Kalinichenko, Sergey Rudenko, Andrii Holovan, Nadiia Vasalatii, Anastasiia Zaiets, Oleksandr Koliesnik, Leonid Oberto Santana and Nataliia Dolynska
Sustainability 2025, 17(18), 8466; https://doi.org/10.3390/su17188466 - 21 Sep 2025
Viewed by 998
Abstract
Smart routing has emerged as a critical enabler of sustainable shipping, addressing the growing demand for energy-efficient, safe, and adaptive vessel navigation in both maritime and inland waterborne transport. This review examines the current landscape of trajectory optimization approaches by analyzing selected peer-reviewed [...] Read more.
Smart routing has emerged as a critical enabler of sustainable shipping, addressing the growing demand for energy-efficient, safe, and adaptive vessel navigation in both maritime and inland waterborne transport. This review examines the current landscape of trajectory optimization approaches by analyzing selected peer-reviewed studies and categorizing them into six thematic areas: AI/ML-based prediction, optimization and path planning algorithms, data-driven methods using AIS and GIS, weather routing and environmental modeling, digital platforms and decision support systems, and hybrid or rule-based frameworks for autonomous navigation. The analysis highlights recent advances in deep learning for trajectory forecasting, multi-objective and heuristic optimization techniques, and the use of real-time environmental data in routing decisions. Supplemental review using Scopus-based topic mapping confirms the centrality of integrated digital strategies, high-performance computing, and physics-informed modeling in emerging research. Despite notable progress, the field remains fragmented, with limited real-time integration, underexplored regulatory alignment, and a lack of explainable AI applications. The review concludes by outlining future directions, including the development of hybrid and interpretable optimization frameworks, and expanding research tailored to inland navigation with its distinct operational challenges. These insights aim to support the design of next-generation navigation systems that are robust, intelligent, and environmentally compliant. Full article
(This article belongs to the Section Sustainable Transportation)
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