Search Results (488)

In this paper, we propose a novel concept of a modular, multiport, single-stage, bidirectional, isolated, three-phase AC-DC converter system. This new system is realized using add-ons to a standard voltage source inverter, including both grid-connected AC-DC converters, like PWM rectifiers, and AC-drive DC-AC inverters. The proposed add-on converters provide isolated DC ports and can be installed into existing inverters of the abovementioned types, with no need for any modification of their topology or control system. Moreover, the add-on converters provide a minimum transistor count and high efficiency. The efficiency of the proposed add-on converters can be further improved by switching the type of pulse width modulation (PWM) scheme based on their operating point. The proposed converter system is validated for a power of 20 kW, an output voltage of 500–800 V DC, and a 40 kHz PWM frequency. Full article

In this work, a dual-band, dual-mode, circularly polarized fully woven textile antenna with capability for Simultaneous Wireless Information and Power Transfer (SWIPT) in wearable applications is presented. The power and the data transfer modes work at 2.4 and 5.4 GHz, respectively. The radiating element is based on a square patch with an asymmetrical U-shaped slot and a chamfered corner. A single-diode rectifier, required for the power transfer mode, is mounted on a carrier thread and then connected to the antenna through a T-match network located at one of the patch corners. This feeding technique simultaneously provides complex conjugate matching to the rectifier and circular polarization. On the other hand, a coaxial probe port is used for the data transfer mode. A prototype was implemented and experimentally characterized. Regarding the power transfer mode, the measured RF-DC conversion efficiency is about 50% when the available power at the rectifier input is −10 dBm, and the axial ratio is smaller than 3 dB. In the data transfer mode, the antenna gain and the axial ratio are 0 and 2 dB, respectively. The experimental results are in good agreement with simulations, validating the proposed structure and design methods, and they are comparable to the state of the art for textile antennas/rectennas. Furthermore, the combination of the fully woven technology and the proposed single-layer layout provides a large degree of integration and robustness, which are valuable characteristics for wearable devices. Full article

Ports are vital components of global and regional supply chains, supporting trade, transport connectivity, and socio-economic development. However, their functionality is increasingly threatened by climatic hazards such as sea-level rise and heat stress, both of which are projected to intensify under future climate change. This study presents a comprehensive framework for assessing the criticality of ports within a national network, demonstrated through its application to the Greek port system, which encompasses a multitude of ports of all types from large international hubs to small island ones. The framework combines openly accessible geospatial and socio-economic data with projections of exposure to sea-level rise and extreme heat within a structured multi-criteria decision-making (MCDM) approach, enabling the identification of critical ports and the prioritization of adaptation needs. Results show that large mainland ports dominate in socio-economic importance and network centrality, while smaller island ports are vital locally due to limited redundancy and high exposure to climatic hazards. By 2100, nearly all ports are projected to experience freeboard reductions below operational thresholds and increased heat-related stress. These results highlight the need for targeted adaptation measures, including engineering interventions for mainland ports and redundancy-enhancing actions for island ports. The proposed framework provides a replicable, data-driven tool to guide evidence-based prioritization of adaptation investments and strengthen climate-resilient maritime transport and coastal management, thereby contributing to the achievement of Sustainable Development Goals (SDGs) 1.5, 9 and 13. Full article

Mangrove forests are biodiverse and highly productive coastal ecosystems, fundamental to fisheries and tourism. However, they are severely threatened by human activities and invasive species, particularly in port areas such as the Port of Santos, necessitating effective environmental management. This study aimed to analyze the risks of biological invasion in mangrove ecosystems stemming from port activities, with a focus on the Port of Santos (PS), Brazil. To achieve this, we conducted a bibliometric review using the Web of Science and Scopus databases, analyzed vessel traffic flows arriving at the PS over 14 years (from 2010 to 2024), and discussed alternatives to address the challenge of biological invasion. The review revealed a significant gap in the scientific literature, as few studies (9.9%, n = 71) address the intersection of maritime transport, invasive species, and mangroves in Latin American contexts. The intense and constant flow of international vessels into the Port of Santos, totaling 15,193 arrivals from more than 200 ports worldwide between 2010 and 2024, poses a persistent threat of biological invasion. This high-volume connectivity, with several foreign hubs exceeding 300 departures in the period, reinforces the role of ships as vectors transporting exotic species in ballast water and through hull fouling. This can destabilize local ecosystems and cause significant socioeconomic losses unless control measures, mediated by effective policies, regulations, and technologies, are implemented in the short term. A spatiotemporal analysis of vessel traffic flows over a 14-year period revealed persistent high-risk corridors for bioinvasion, directly linking maritime activity patterns to the threat level for adjacent mangrove ecosystems. The data indicate a substantial challenge for the PS, yet one with a high potential for resolution in the medium term, contingent upon investment in technology and regulation. Full article

Digital transformation (DT) has become a strategic priority for global ports; however, many in developing countries, including Indonesia, face challenges in translating digital initiatives into measurable business performance (BP). This study examines the impact of DT on BP through the mediating roles of supply chain integration (SCI) and operational performance (OP) within Indonesian ports, using the Dynamic Capabilities Theory (DCT) framework. A quantitative survey of 128 operational managers from state-owned ports was analyzed using partial least squares structural equation modeling. The findings reveal that DT significantly improves SCI and OP, both of which positively influence BP. Moreover, SCI and OP jointly mediate the DT–BP relationship, highlighting that digital technologies create value only when integrated into coordinated processes and operational routines. The study underscores that DT should be managed as a strategic transformation aligning technology, operations, and interorganizational collaboration. For port managers, strengthening digital connectivity across internal and external networks, supported by governance and incentive mechanisms, is essential to enhance visibility, responsiveness, and resilience. Theoretically, this research advances DCT by demonstrating how DT functions as a reconfiguring capability realized through SCI and OP, providing empirical insights from developing-country port contexts. Full article

Accurate water-level prediction is a critical component for ensuring safe maritime navigation, optimizing port operations, and mitigating coastal flooding risks. However, the complex, non-linear spatiotemporal dynamics of water systems pose significant challenges for current forecasting models. The proposed framework introduces three key innovations. First, a dual-weight graph construction mechanism integrates geographical proximity with Dynamic Time Warping (DTW)-derived temporal similarity to better represent hydrodynamic connectivity in coastal and estuarine environments. Second, a state-aware weighted loss function is designed to enhance predictive accuracy during critical hydrological events, such as storm surges and extreme tides, by prioritizing the reduction in errors in these high-risk periods. Third, the WS-STGTN architecture combines graph attention with temporal self-attention to capture long-range dependencies in both space and time. Extensive experiments are conducted using water-level data from five stations in the tidal-influenced lower Yangtze River, a vital artery for shipping and a region susceptible to coastal hydrological extremes. The results demonstrate that the model consistently surpasses a range of baseline methods. Notably, the WS-STGTN achieves an average reduction in Mean Squared Error (MSE) of 27.6% compared to the standard Transformer model, along with the highest coefficient of determination ($R^2\approx 0.96$) across all datasets, indicating its stronger explanatory power for observed water-level variability. This work provides a powerful tool that can be directly applied to improve coastal risk management, marine navigation safety, and the operational planning of port and coastal engineering projects. Full article

Efficient coordination among software modules is essential for biomimetic robotic systems, much like the interaction among organs in a biological organism. However, implementing inter-process or inter-module communication in autonomous systems remains a complex and time-consuming task, particularly for new researchers. Simplifying inter-module communication is the central focus of this study. To address this challenge, we propose the DigitalTwinPort framework, a novel communication abstraction inspired by the port-based connectivity of embedded hardware systems. Unlike middleware-dependent solutions such as ROS, the proposed framework provides a lightweight, object-oriented structure that enables unified and scalable communication between software modules and networked devices. The concept is implemented in C++ and validated through an autonomous surface vehicle (ASV) developed for the RobotX Challenge. Results demonstrate that the DigitalTwinPort simplifies the development of distributed systems, reduces configuration overhead, and enhances synchronization between digital and physical components. This work lays the foundation for future digital twin architectures in embodied Internet systems, where software and hardware can interact seamlessly through standardized digital ports. Full article

With the development and widespread application of information technology, cybersecurity has become a focal point in all industry sectors. The maritime sector is no exception, with both physical and cyber threats. This survey first highlights, from a system engineering and information technology perspective, the specific architectures of on-vessel and in-port systems, as well as the communication equipment connecting them. Subsequently, cyber attacks in maritime and port domains and their potential consequences are described from various angles. Examples of real cases of cyber attacks are also reported. An overview of current key techniques used in vulnerability analysis, attack detection, and security protection is proposed before discussing cybersecurity issues in the maritime and port sectors from the particular perspective of discrete event systems. Various systems used in maritime and port domains are modeled as automata or Petri nets. Some analysis, detection, and protection approaches are then proposed to illustrate the potential of discrete event systems in this domain. Full article

This study examines the evolving relationship between the Port of Motril and the adjacent fishing community of El Varadero. The reduction in fishing quotas and the port’s transformation into a maritime transport hub have not only reshaped the connection between the area and the port but have also contributed to the gradual decline of the local community. Through a community survey conducted among residents of the fishing neighborhood and the urban center (n = 65), we assessed community assets, psychological sense of community, and collective self-efficacy in this coastal area in southern Granada. The survey findings were supplemented with interviews with key informants from the local fishing sector (n = 5). The results indicate that residents of the fishing neighborhood perceive a higher prevalence of social problems and report a diminished sense of belonging. The community’s historical ties to the port have progressively weakened, exposing residents to ongoing socio-economic decline. This study explores the potential of fishing cultural heritage as a resource for local development and highlights the need for integrated governance between the fishing sector and the local authorities. Full article

This study aims to provide a detailed analysis of the design choices and economic sustainability aspects associated with the implementation of shore-to-ship electrification, commonly known as “cold ironing”, in port docks, pertaining to the Italian context. This innovative technological solution aims to reduce the environmental impact of port operations by allowing docked ships to turn off their engines and connect directly to the shore-side power supply. A detailed analysis of present standards and applicable legislation is presented and implemented. Therefore, the objective of this work is to determine the conditions that make shore-side power supply economically sustainable and to study the most plausible future scenarios of greatest interest through the definition of possible management models integrated into the national and EU fiscal system. This enables a quantitative and reliable assessment of the current cold ironing incentive policies in promoting this technology, with some guidelines provided for the future promotion of this sector. Full article

Maritime transportation plays a vital role in international trade and commerce, with ports serving as critical points of connection between land and sea transportation systems. The operational efficiency of port facilities is essential to ensure the uninterrupted flow of goods and services, making port safety a top priority for governments, authorities, and shipping companies. Due to the importance of Occupational Health and Safety (OHS) within port environments, it is crucial to develop a structured framework in order to collect and analyze port accidents data. Today there are several different national agencies, private organizations, and/or local regulatory bodies taking charge of these data over different areas, each with variations in how they document and classify the events; in addition these are frequently limited to only major disasters and/or summary statistics. This paper aims to create a general framework to collect and fuse open-source port accident data from different sources in a structured way and to analyze the safety conditions of port facilities by conducting a comparative evaluation based on design of experiment (DoE). Through this analysis, we identify common causes of accidents and injuries in port facilities, as well as any differences in safety conditions across regions, types of port facilities, and other relevant factors. This information can be used to inform policies and practices aimed at improving port safety, reducing accidents and injuries, and ultimately enhancing the efficiency and sustainability of maritime transportation systems. The motivation to develop this research relies on the necessity to define requirements for the development of innovative solutions to be developed by the authors using modeling and simulation (M&S) and XR (extended reality) in order to increase safety in these contexts. Full article

The inland canal environment is highly complex, and effective management of vessel traffic necessitates accurate forecasting. However, pronounced fluctuations in vessel traffic flow make reliable prediction particularly challenging in traffic-intensive areas, including ports and lock regions. Furthermore, strong nonlinearities in vessel traffic dynamics—exacerbated by factors such as lock operations and adverse weather conditions—further exacerbate the difficulty of accurate forecasting. To address these challenges, this paper proposes a WVMA-LSTM prediction framework that decomposes vessel traffic flow series prior to forecasting. The proposed model consists of three main components. First, vessel traffic data are decomposed using variational mode decomposition (VMD), while the parameters of VMD are simultaneously optimized via the whale optimization algorithm (WOA). Second, the Pearson correlation coefficient (PCC) is employed to select highly correlated components for input into the processing layer, thereby mitigating the impact of noise on prediction accuracy. Finally, the LSTM module combined with a multi-head attention mechanism is utilized to extract both trend information and local fluctuations from the sequences, after which a fully connected layer integrates the prediction outputs to obtain the final result. Experimental results demonstrate that the proposed model achieves an R² exceeding 0.89 when predicting vessel traffic at locks and other complex environments, indicating high forecasting accuracy and robustness and offering valuable support for smart canal traffic management. Full article

Ports often act as bottlenecks in import cycles. Yet feasibility assessments of port–dry port systems still privilege distance/location over the process dynamics that generate time and cost. This paper proposes a process-centred feasibility method that links process analysis and reengineering, operational cycle design, and economics. We map AS-IS/TO-BE activities, design shuttle-train operations between port and dry port, and estimate costs via a time-driven approach aligned with TDABC. The method is applied to the Port of Genoa—Rivalta Scrivia dry port. Consolidating containers to a single inland destination and relocating customs clearance to the dry port via Fast Corridor stabilises yard operations, removes re-handling in the port-to-dry-port cycle, reduces dwell, and improves train formation and reliability. Under these conditions, the process-based configuration becomes time- and cost-competitive vis-à-vis all-road and conventional block-train baselines for relevant inland destinations. This paper reframes feasibility from a distance-based view to a process, cycle, and economics logic, offering managerial guidance and policy implications on regulatory enablers that unlock dry-port benefits. Full article

Background/Objectives: Peripheral intravenous catheters are commonly employed to administer intravenous therapy to hospitalized patients. However, their use can result in complications, with phlebitis occurring in approximately 11% of cases and bloodstream infections in about 0.18%. This study aimed to enhance PIVC management in a local hospital by implementing a comprehensive care bundle to mitigate these complications. Methods: This quality improvement study involved the collection of data from 1330 PIVCs in adult patients, both prior to and following the implementation of the intervention. Data collection occurred between June 2022 and November 2023, employing the validated Peripheral Intravenous Catheter-Mini Questionnaire (PIVC-miniQ). This instrument comprises 16 observation points that assess phlebitis-related signs and symptoms, the integrity of PIVC dressings and IV connections, and the adequacy of documentation. Results: The prevalence of phlebitis decreased from 15.1% at baseline to 9.4% post-intervention (p = 0.018). Significant predictors of phlebitis included the intervention, ward, gender, and PIVC gauge. Improvements were also noted in PIVC dressing and IV connection practices, as well as documentation standards (p < 0.001). Closed integrated PIVCs outperformed ported PIVCs in the PIVC-miniQ scores after the intervention (p < 0.001). A statistically significant difference was observed in the mean PIVC-miniQ sum score post-intervention compared to baseline (p < 0.001). Conclusions: This study indicates that implementing a care bundle can enhance the quality of PIVCs and reduce the prevalence of phlebitis. Further high-quality research is needed to identify the most effective care bundles for preventing PIVC-related complications. Full article

Echocardiography remains a vital part of the initial assessment and monitoring of oncological patients. It allows for proper treatment selection but can also reveal life-threatening complications, including impaired left ventricular function or thromboembolism. It can rarely detect intracardiac masses that require further investigation. In the presented case, a 51-year-old female patient with left-sided breast cancer, who had undergone neoadjuvant chemotherapy, was hospitalised due to a right atrial mass identified via routine transthoracic echocardiography (TTE). Initial anticoagulation therapy showed no clinical improvement. Follow-up TTE revealed a 12 × 19 mm hyperechogenic, mobile mass in the right atrium (RA). Computed tomography angiography (CTA) ruled out pulmonary embolism and revealed that the mass was located close to the tip of the vascular access port. Transoesophageal echocardiography showed that the lesion was not connected to the vascular port. Based on location and mobility, the lesion was most consistent with a cardiac myxoma. After the Heart Team made a decision, endovascular intervention using a vacuum-assisted device was performed without complications. Histopathological examination excluded thrombosis and myxoma, revealing a fibro-inflammatory lesion. A multimodality approach is necessary to assess RA masses. However, even an extensive evaluation could be misleading, so treatment options should always be subject to the Heart Team’s decision. Full article