Search Results (231)

Bottom-up ship emission inventories derived from Automatic Identification System (AIS) data are normally reported on kilometre-scale grids, which merge port waters that perform very different functions. Working with an AIS-based STEAM inventory for the Yangtze River Delta (YRD), we ask a question that gridded inventories rarely separate: are the cells where ships accumulate time the same cells where they emit? To answer it, we define the Static–Dynamic Ratio (SDR), the ratio of hotelling (auxiliary-engine) to propulsion (main-engine) emissions within a cell, and use it to classify YRD waters without recourse to external port charts. Hotelling-dominated cells occupy 17.7% of the sea area and accumulate 59.3% of all ship-hours, a ship-hour density seven times that of transit-dominated fairways, yet they carry only 22.4% of NO_x. A vessel at anchor emits about one-eighth as much NO_x per hour as one under way, and the two effects nearly cancel. The cancellation is species dependent: low-load correction factors are steeper for sulfur and particulate species than for NO_x, so hotelling zones reach relative SO₂ and PM_2.5 densities of 1.21 and 1.09 against 0.89 for NO_x. Coarsening the same activity field from 100 m to 1 km drops the share held by the busiest 1% of cells from 70% to 50%, showing how kilometre grids manufacture apparent continuity along shipping lanes. Activity hotspots are therefore not emission hotspots, and anchorage-targeted measures such as shore power are best justified by particulate and sulfur exposure near populated coasts rather than by their share of the regional NO_x burden. Full article

This paper investigates a formation tracking problem for underactuated surface vessels (USVs) subject to collision avoidance and input saturation constraints. Many existing APF-based formation-control approaches formulate collision avoidance using a single reference point or an inter-center distance, which may provide insufficient geometric information during close-range maneuvers. To improve navigation safety, an elliptical disk-based collision avoidance mechanism is developed by introducing safety points at the bow, stern, port, and starboard sides of each USV, such that multiple characteristic-point distance constraints can be simultaneously enforced. To address unknown nonlinearities caused by model uncertainties and external disturbances, a neural network-based observer is designed to estimate unavailable velocity states and lumped disturbances. Distributed control laws are synthesized by integrating artificial potential functions (APFs), the observer, and a backstepping technique. Additional controllers are introduced to address the input saturation and underactuated issues while preserving the collision avoidance capability. Stability of the closed-loop system is rigorously established via Lyapunov theory. Simulation results demonstrate that the proposed approach achieves safer close-range maneuvering performance compared with conventional single-point methods. Full article

Air pollution in urban and coastal regions is increasingly shaped by interactions among port operations, freight logistics, urban mobility systems, spatial development patterns, and governance arrangements. Although emission reduction technologies and regulatory measures have advanced significantly, their implementation frequently remains distributed across sector-specific institutional and operational domains. This paper introduces the concept of Air-Aware Port–City–Logistics Systems, proposing an integrated governance framework that treats air quality as a system-level outcome of linked maritime, logistics, urban transport, spatial, technological, and adaptive processes. Drawing on a structured interdisciplinary synthesis of literature in transport planning, maritime economics, logistics, environmental governance, air-quality management, and resilience, the study identifies key gaps in cross-sectoral coordination and in the governance of interdependencies influencing air-quality outcomes. The framework maps relationships among emission sources, transport and logistics flows, spatial configurations, population exposure, institutional coordination, technological and data systems, and adaptive capacity, thereby identifying potential intervention points across the port–city–logistics system. Its distinctive contribution lies not merely in combining these dimensions, but in organising them through a governance-oriented architecture in which monitoring, operational decisions, institutional responses, and adaptive learning are treated as interconnected processes. The framework also incorporates resilience and risk perspectives, emphasising adaptive governance approaches capable of responding to disruptions, changing demand patterns, climatic pressures, and other external environmental influences. By advancing a systems-based perspective, the paper contributes to air quality management and policy development through the integration of port–city interfaces, freight distribution networks, mobility planning, exposure considerations, and institutional decision-making within a unified analytical framework. As a conceptual framework, AAPCLS provides a transferable basis for future empirical application, contextual adaptation, and policy-oriented analysis rather than a validated operational model. Full article

Subjected to high-intensity development, enclosed tropical islands frequently face severe spatial resource constraints and acute risks of ecological degradation. To seek a comprehensive solution to multidimensional spatial conflicts, this study selected Hainan Island—a region facing development pressure from the Free Trade Port construction—as the study area. By coupling the XGBoost-SHAP, NSGA-II, and PLUS models, we constructed an integrated modular spatial planning framework of “mechanism interpretation—macro optimization—micro reconstruction”. The main findings are as follows. (1) Over the past 15 years, the fragile ecosystem of the island has faced immense pressure. Lacking an external buffer hinterland, land-use transitions exhibited a distinct chain transmission characteristic of “built-up land occupying agricultural land, and agricultural land squeezing forest”. This internal spatial cascading substitution constituted the core mechanism of ESV decline. (2) The reconstruction of the spatial pattern is governed by dual thresholds of natural constraints and economic pulling. A rigid ecological defense baseline (NDVI ≥ 0.40) restricts disorderly urban sprawl, while spatial inflection points (8.46 km from the coastline and 271 m from roads) precisely delineate the coastal and traffic-oriented agglomeration boundaries for built-up land. (3) Among the predefined scenarios, the Sustainable Development (SD) scenario emerges as the optimal pathway. By proactively reducing inefficient agricultural land space at the macro level and strictly implementing identified threshold controls alongside “infill” urban agglomeration at the micro level, the SD scenario is expected to successfully achieve a Pareto-optimal synergy between socioeconomic growth and the restoration of regional ESV. This study not only establishes an objective benchmark for the refined multi-objective spatial governance of the Hainan Free Trade Port, but also provides a referential planning paradigm for vulnerable enclosed islands globally facing high-intensity anthropogenic stress. Full article

Port-related maritime emissions constitute a significant source of urban air pollution and greenhouse gas emissions, particularly in rapidly developing coastal cities. Within this context, the present study quantifies ship-related emissions at the Port of Casablanca, Morocco’s largest and most strategically important port, and evaluates their associated environmental and socio-economic impacts. A bottom-up methodology was applied to estimate emissions from vessel operations between 2017 and 2021. The inventory integrates vessel characteristics, engine specifications, operational load factors, emission factors, and the duration of maneuvering and hotelling phases to estimate emissions of CO₂, SO₂, NO_x, CO, NMVOCs, PM, PM₁₀, and PM_2.5. The emission inventory was subsequently coupled with damage cost factors to assess the external costs associated with shipping emissions. The obtained results demonstrate that CO₂ was the dominant emitted pollutant, representing approximately 97% of total emissions, whereas NO_x and SO₂ accounted for 2% and 1%, respectively. Bulk carriers emerged as the principal emission source (44%), followed by container vessels (36%), with the highest emission levels observed during 2018–2019, coinciding with increased port operations. Furthermore, the integration of emission inventories with damage cost factors demonstrated that NO_x, although emitted in much smaller quantities than CO₂, exerts a disproportionately higher environmental and societal burden due to its impacts on public health and ecosystem quality. This study provides one of the first integrated bottom-up emission inventories and external cost assessments for a Moroccan port. The proposed framework supports evidence-based decision-making for sustainable port management and demonstrates the need for emission reduction strategies that simultaneously address climate change and air quality objectives. Full article

Coastal shipping systems experience complex functional degradation and recovery under port congestion, extreme weather, channel restrictions, and environmental constraints. To support sustainable maritime governance and port management, this paper proposes an AIS–MRV consistency-enhanced dynamic network assessment framework. The framework converts vessel trajectories into a dynamic maritime traffic network composed of ports, anchorages, fairways, and traffic corridors, and it constructs normal-state baselines by region, time window, and vessel type. It jointly measures system functionality, resilience loss, recovery time, network efficiency, anchorage congestion, route deviation, and an AIS-derived green operational penalty. It also compares AIS-derived green activity proxies with MRV annual CO₂ reports to assess external consistency. The short-term real-AIS experiment identifies 70 traffic nodes and produces comparable functionality curves and Resilience–Green Index values for five representative port regions. The DGX full-year AIS baseline experiment processes 365 daily AIS files and generates 22.76 million vessel-hour records. Under network-parameter perturbations, the Spearman correlations of the $Q^{*}$ time series range from 0.900 to 1.000, and the Spearman correlation of the five-region RGI ranking remains 1.000. The Los Angeles/Long Beach event window shows a standardized functionality difference of −0.076 relative to spatial controls, with a bootstrap 95% confidence interval of [−0.090, −0.023]. The five regions show an index range of 0.3168–0.8391, and Puget Sound remains the top-ranked region in 86.27% of 10,000 random weight perturbations. The MRV consistency test indicates a moderate positive correlation between the AIS vessel-size proxy and annual CO₂ emissions, while the size-weighted AIS activity proxy is also positively correlated with reported emissions. The framework provides a reproducible basis for identifying vulnerable shipping segments, assessing traffic recovery, and supporting port management, congestion governance, and green shipping decisions. Full article

Touchless interfaces for embedded systems require models that are both compact and evaluated under protocols that reflect realistic generalization. Public low-resolution gesture datasets can obscure this requirement because repeated samples, temporal neighbors, or subject identity may leak across train and test partitions. This study presents a leakage-aware multi-corpus benchmark in which four public corpora are evaluated within their own dataset-specific partitions after conversion to a common 8 × 8 depth representation when needed: a public IEEE DataPort ToF CSV with 8400 frames from four gestures, DS.GestureRecognition_TOF.1.0 with 3109 frames extracted from 40 low-resolution ToF sequences and three gestures, the depth component of the public Kinect+Leap dataset with 1400 samples from 14 subjects and 10 gesture classes, and the public Senz3D depth archive with 1320 samples from 4 subjects and 11 gesture classes. No blurred RGB image dataset, deblurring target, or synthetic blur augmentation is produced in the experiments; the only spatial reduction applied to external depth corpora is deterministic block averaging for a shared low-resolution depth input. The term multi-corpus is used here to clarify scope: the experiments do not train on one dataset and test on another, but instead compare optimistic random splits against structure-aware alternatives matched to each corpus: chronological block-aware, sequence-aware, and subject-wise evaluation. On the original IEEE ToF benchmark, the best macro F1-score decreases from 1.0000 under random splitting to 0.8494 under block-aware evaluation. On DS.GestureRecognition_TOF.1.0, random splitting again reaches 1.0000, whereas the best sequence-aware result falls to 0.6697. On the downsampled Kinect+Leap depth benchmark, random frame classification reaches 0.7639 macro F1, while subject-wise evaluation drops to 0.0566. On Senz3D reduced to 8 × 8, random frame classification reaches 0.9068 macro F1, while subject-wise evaluation drops to 0.0717. Device-side validation on an NVIDIA Jetson Nano Developer Kit preserved a macro F1-score of 0.8667 for the selected GRU on the primary IEEE ToF dataset with 14.48 ms/window steady-state CPU latency. The results show that low-resolution gesture recognition conclusions are strongly protocol- and corpus-dependent: compact temporal models remain viable for genuine ToF streams, but naive random splitting can substantially overstate generalization, and subject-wise recognition after aggressive 8 × 8 conversion remains difficult for the evaluated datasets and architectures. Full article

The complex and nonlinear load characteristics of Hall thrusters remain a key challenge in the design of propulsion power-supply output stages. In existing power-supply simulations for electric propulsion systems, the Hall thruster is often simplified as a fixed impedance or a prescribed current source, which makes it difficult to capture the time-synchronized interaction during simulation between the power-supply output stage and the thruster discharge process. To address this issue, this study encapsulates a one-dimensional discharge model as an externally callable thruster slave and proposes a HallThruster.jl–Simulink–Saber co-simulation method. The proposed method enables synchronized bidirectional exchange between the power-port voltage $V_{cmd}$ and the thruster discharge current $I_{out}$. The results show that the discharge current under the co-simulation condition exhibits a sustained low-frequency response at approximately 15.0 kHz. Compared with a fixed-voltage standalone simulation, the co-simulation preserves the same principal oscillation band and overall internal-field structures, while small but observable differences remain in instantaneous phase, local waveform shape, harmonic amplitudes, and high-gradient regions of the internal fields. The proposed method provides a computational framework for investigating dynamically coupled port behavior between a Hall thruster and a representative power-supply output stage. Full article

Automated guided vehicles (AGVs) are key transportation resources in automated container terminals, where operational scheduling and charging decisions exhibit strong spatiotemporal coupling characteristics. When AGVs are assigned to transport “reefer” containers, interruptions in external power supply during transit may lead to temperature fluctuations, posing potential risks to cargo quality and transportation safety. To address this issue, this paper proposes a two-stage coordinated optimization framework for AGV operations and charging, considering reefer container temperature constraints. Specifically, an AGV transportation scheduling model is first developed to characterize quay-crane operations, yard allocation, AGV travel processes, battery dynamics, and reefer container transit-time limitations associated with temperature maintenance requirements. Subsequently, a port microgrid scheduling model integrating charging stations, photovoltaic generation, wind power, and energy storage systems is established to coordinate AGV charging strategies with energy system operations. Based on these models, a two-stage optimization framework is constructed, in which AGV task assignment and yard allocation are optimized in the first stage to improve operational efficiency, while energy scheduling is optimized in the second stage to minimize system operating costs under the operational decisions obtained in the first stage. Numerical results demonstrate that the proposed method effectively reduces the transportation time of reefer containers, alleviates temperature-related transportation risks, enhances the coordination between logistics operations and energy management, and improves terminal operational efficiency while ensuring the safety and quality of reefer container transportation. The proposed framework provides an effective solution for the integrated optimization of logistics and energy systems in automated container terminals. Full article

Background: Synergistic development of the coupled and coordinated relationship of medical service capacity, residents’ health level, and regional economic development (MRR) is crucial for realizing the “Healthy China 2030” strategy. This study aims to analyze the spatiotemporal features of the coupling coordination degree (CCD) of MRR. Methods: Based on panel data from 2012 to 2022, we constructed the MRR evaluation system. The entropy method was adopted to calculate the comprehensive index of each subsystem, and the coupling coordination degree model (CCDM) was used to evaluate the CCD of MRR during the study period. Furthermore, we applied exploratory spatial data analysis, the Dagum Gini coefficient decomposition, extreme gradient boosting (XGBoost) and Shapley Additive Explanations (SHAP) to explore spatiotemporal dynamic characteristics and factors associated with CCD. Results: (1) Throughout the study period, the overall value of the MRR composite system increased from 0.3798 to 0.4097, with an average annual growth rate of 0.54%. (2) CCD remained generally low, dominated by the basic coordination type. Both global and local spatial autocorrelation analyses revealed significant differentiated spatial clusters of high and low CCD, with the overall spatial distribution fitting a “high in the east, low in the west” pattern. Inter-regional gaps are the main reason for the overall differences. (3) In the full sample, Population density (PD)was the dominant external predictive contributor, with a mean absolute SHAP value of 0.028, followed by Internet broadband access ports (IBAP)and Government health expenditure (GHE). The key predictive factors differed among regions. Conclusions: This study clarifies spatiotemporal evolution and predictive contributors of CCD. These findings provide valuable insights for decision-makers to promote coordinated MRR development. Full article

Ports are increasingly required to respond to environmental regulation, digital transformation, and demands for more sustainable logistics systems. Although research on smart ports, green ports and innovation ecosystems has expanded, less attention has been given to how Open and Sustainable Innovation is enabled, constrained and institutionalised within public port authorities. This study examines this process in the Port of Sines, Portugal’s largest port and a strategic Atlantic logistics hub. A qualitative single-case study was conducted, drawing on institutional documents, nine semi-structured interviews, observational material and MAXQDA-supported qualitative coding. The analysis was structured around four interdependent dimensions: environmental, organisational, cultural and technological. The findings show that Open and Sustainable Innovation is enabled by European sustainability agendas, digitalisation initiatives, the NEXUS Agenda and multi-stakeholder collaboration. However, it remains only partially institutionalised. Organisational fragmentation, limited learning routines, uneven cultural readiness, data-sharing concerns and dependence on externally funded projects constrain long-term innovation capabilities. The study contributes by conceptualising Open and Sustainable Innovation in public port ecosystems as an institutionalisation process rather than as a set of isolated digital, environmental or collaborative initiatives. It offers practical insights for strengthening governance coordination, stakeholder trust, data-sharing arrangements and organisational learning in sustainable port transformation. Full article

In the context of rural construction, studying particle diffusion alongside residents’ satisfaction with rural external heated kangs provides important support for upgrading heating facilities and improving domestic infrastructure in the northwest arid regions of China. This study takes a single rural household equipped with an external fire kang in Baoji as the research object. From the perspectives of operational and service management in human settlements, the spatio-temporal diffusion characteristics of particulate matter in the outdoor combustion port, living room, and bedroom during the winter heating period are continuously monitored, and data on resident satisfaction are collected through a questionnaire. The results show that, during the external kang’s heating period, the spatial concentrations of particulate matter decrease in the following order: combustion port > living room > bedroom. Concentrated morning and evening kang heating creates a typical bimodal distribution of outdoor particulate matter concentration, with peaks at 8:00 am and 8:00 pm. During the ignition period, coarse particles (PM₁₀) are mostly released, while the proportion of fine particles (PM_2.5, PM_1.0) increases during the stable combustion period. During the sealing period, the concentration of fine particles doubles. After extinguishing, PM₁₀ decays rapidly due to gravity deposition, while PM_1.0 shows a longer environmental retention time due to its slow diffusion. The core diffusion process of the particulate matter mainly occurs within a distance of 5–15 m from the combustion port. The resident satisfaction survey shows moderate comprehensive satisfaction with external heated kangs, at 3.10 points on a 5-point scale. Addressing existing problems and proposing relevant strategies, this study provides a theoretical basis and technical support for the rational transformation of external heated kangs in the arid areas of Northwest China. Full article

Ports and industrial regions increasingly call clean-fuel projects “hubs,” although the market functions behind those projects are often still being developed. In Ulsan, this language has shifted from the Northeast Asian Oil Hub to an oil–gas hub and then to a hydrogen–ammonia vision. This article does not ask whether the infrastructure matters. It asks whether the “hub” label is supported by publicly visible evidence. It develops a public-evidence framework for calibrating claims against evidence and adds a public-label validation layer to sustainability-transition and port-governance analysis. The framework is applied to public documents on Ulsan’s oil, oil–gas, and hydrogen–ammonia projects. The oil-hub narrative began with the use of stockpiling assets and tankage leasing. The North Port later became an oil/LNG terminal through project vehicles, terminal-use agreements, EPC contracts, financing, and commercial operation. These records confirm terminal implementation, not the existence of a trading hub. The South Port is better understood as a low-carbon infrastructure vision, while the April 2026 ammonia-bunkering operation is treated as a port-system fuel-supply milestone. By linking public labels to evidence of implementation, recurring use, coordination routines, market institutions, and external recognition, the framework treats hub naming as a sustainability–accountability issue tied to SDG-related infrastructure claims and ESG disclosure integrity, rather than merely as project branding. Full article

Navigation lock manifolds are key components of filling-and-emptying systems, and port-flow distribution affects chamber flow stability and filling efficiency. Under unsteady filling conditions, port-flow distribution is governed by discharge variation and manifold geometry, making rapid prediction and engineering-constrained screening challenging. This study develops a surrogate-assisted prediction and Pareto-screening framework for a large-scale navigation lock manifold. Three-dimensional computational fluid dynamics (CFD) simulations were used to examine unsteady port-flow evolution. The peak-flow condition was selected as a representative control condition, and the flow non-uniformity coefficient α and system resistance coefficient ξ were used as performance indicators. Based on 243 parametric CFD samples and 144 independent external test samples, artificial neural network (ANN), Gaussian process regression (GPR), and support vector regression (SVR) models were evaluated. ANN performed best, with independent-test R² values of 0.9999 and 0.9928 for α and ξ. Feature-attribution analysis identified port width, culvert height, and port number as dominant variables. Pareto screening within a predefined engineering design space identified representative candidates with CFD verification errors below 1.1%. The TOPSIS-based candidate reduced ξ by 32.2% while maintaining α nearly unchanged. Full article

The NIS2 Directive strengthens governance and time-bound incident reporting obligations for cybersecurity in critical sectors, while Industrial Ethernet and IT/OT convergence expose deterministic shop-floor networks to broader threat propagation. This paper introduces an engineering approach to the application of the NIS2 Directive for reducing the detection latency at the OT level without excessively increasing the costs. The proposed architecture is based on an innovative complementary device, the Early Warning System (EWS), tailored for OT monitoring and designed for integration with enterprise monitoring (Security Information and Event Management—SIEM) and operational response (SOC/MDR—Security Operations Center/Managed Detection and Response). The EWS adopts a silent device paradigm: because the honeypot has no production role, any interaction becomes a high-confidence signal, minimizing false positives. The EWS is freely available open-source and, to fit heterogeneous plants, it offers two deployment modes, both with zero impact on network latency and timing: Full Mode combines passive monitoring via SPAN/port mirroring with a low-interaction honeypot, while Light Mode provides a pure decoy for resource-constrained edge hardware. The implementation is containerized (Docker) and forwards events to an external SIEM. Two validation steps are presented: the first, on a real PROFINET robotic cell using the Full-mode, demonstrates the zero false positives in normal operations, the detection of reconnaissance scans, baseline deviations, and ARP spoofing attempts; while the second, on three emulated industrial control systems using the ICS-NAD dataset, shows the effectiveness in realistic industrial applications. Full article