M. Dale Stokes, David R. Nadeau, James J. Leichter
An ongoing challenge in pelagic oceanography and limnology is to quantify and understand the distribution of suspended particles and particle aggregates with sufficient temporal and spatial fidelity to understand their dynamics. These particles include biotic (mesoplankton, organic fragments, fecal pellets, etc.) and abiotic (dusts, precipitates, sediments and flocks, anthropogenic materials, etc.) matter and their aggregates (i.e., marine snow), which form a large part of the total particulate matter > 200 μm in size in the ocean. The transport of organic material from surface waters to the deep-sea floor is of particular interest, as it is recognized as a key factor controlling the global carbon cycle and hence, a critical process influencing the sequestration of carbon dioxide from the atmosphere. Here we describe the development of an oceanographic instrument, the Pelagic Laser Tomographer (PLT), that uses high-resolution optical technology, coupled with post-processing analysis, to scan the 3D content of the water column to detect and quantify 3D distributions of small particles. Existing optical instruments typically trade sampling volume for spatial resolution or require large, complex platforms. The PLT addresses this gap by combining high-resolution laser-sheet imaging with large effective sampling volumes in a compact, deployable system. The PLT can generate spatial distributions of small particles (~100 µm and larger) across large water volumes (order 100–1000 m<sup>3</sup>) during a typical deployment, and allow measurements of particle patchiness over spatial scales to less than 1 mm. The instrument’s small size (6 kg), high resolution (~100 µm in each 3000 cm<sup>2</sup> tomographic image slice), and analysis software provide a tool for pelagic studies that have typically been limited by high cost, data storage, resolution, and mechanical constraints, all usually necessitating bulky instrumentation and infrequent deployment, typically requiring a large research vessel.
This case study presents state‐of‐the‐art, multimodal structural reliability and risk evaluation methodology, particularly suitable for naval architecture, transportation and marine engineering applications.Existing reliability methods do not easily tackle systems with a number of critical components higher than 2, while the advocated multimodal reliability and risk evaluation methodology has no limitations on the system's number of dimensions, parts or components. The 4400 TEU container vessel's onboard measured deck panel stresses raw data, collected during numerous vessel's trans‐Atlantic crossings, was analysed. Risk of ship hull and panel structural damage caused by excessive whipping (slamming and springing) wave loads, representing types of highly nonlinear wave‐induced vibrations, are among primary safety concerns for the contemporary marine transportation industry. It is often challenging to accurately forecast excessive vessel's deck panel hot‐spot stresses, possessing complex nonlinear, nonstationary properties. The proposed multimodal hypersurface reliability method fully accounts for a large number of structural components, as well as dynamic nonlinearities. Lab testing may often be disputed, as obtained measurements will depend on biased incident wave properties and model scales. As a result, the onboard dataset, obtained from a particular cargo ship, operating in the North Atlantic provides especially valuable insights into an overall dynamic vessel hull system's durability and reliability.This investigation aimed at providing generic state‐of‐the‐art reliability methodology, enabling accurate extraction of pertinent information about vessel hull system's dynamics, e.g., deck panel hot‐spot stresses, derived from the onboard sensor‐recorded time histories. Utilising proposed hypersurface reliability methodology, structural failure, hazard or damage risks may be effectively yet accurately forecasted, based on spatially distributed vessel deck panel stresses. The presented multimodal state‐of‐the‐art reliability methodology may be particularly suitable for the evaluation of structural hazards of large dynamic systems, having virtually unlimited numbers of principal/key components. The presented study made use of the full scale onboard measured dataset, kindly provided by Det Norske Veritas, Oslo, Norway (DNV), which is commercially valuable on its own.
High-resolution and high-precision marine gravity reference maps are core prerequisites for the practical application of gravity-assisted inertial navigation algorithms, and their accuracy directly determines the performance of the navigation system. In view of the problems existing in the current geographic rectangular grid gravity reference map, such as severe polar deformation, poor adjacent consistency, and low positioning accuracy in high latitudes, this study introduces a hexagonal grid system to construct a gravity reference map. It systematically analyzes its compatibility and accuracy in navigation applications. A multi-resolution hexagonal grid scheme with a 7-aperture structure is further proposed to meet the characterization requirements of gravitational fields with different complexities. Experimental verification shows that the accuracy of the gravity-assisted inertial navigation algorithm improved by 0.4%, while that of gravity sequence matching improved by 50%. The proposed hybrid resolution grid can achieve a maximum gravity data compression rate of 68% while ensuring navigation accuracy, especially with regard to the computational efficiency and accuracy requirements of gravity-assisted inertial navigation.
Recently, the IMO has completed the guidelines on the life cycle greenhouse gas intensity of marine fuels to accelerate the application of alternative fuels. Low-carbon fuels may persist for decades and have become a key transitional phase in replacing marine fuels. A more comprehensive methodology for evaluating the carbon emission levels of marine fuels was explored, and the carbon emissions and environmental impacts of a 150,000-ton shuttle tanker under 19 dual-fuel power scenarios were evaluated using the Energy Efficiency Design Index (EEDI) and life cycle assessment (LCA) method. The results show that liquefied natural gas (LNG) has a higher carbon control potential level compared to liquefied petroleum gas (LPG) and methanol (MeOH), while LPG is superior to MeOH based on EEDI evaluation. LCA analysis results show that MeOH (biomass) has the best carbon control potential considering the carbon emissions of the well-to-tank phase of the fuel, followed by LNG, LPG, MeOH (natural gas, NG), and MeOH (coal). However, MeOH (NG) and MeOH (coal) had greater negative environmental impacts. This study provides method support and a direction toward improvement for revising related technical specifications and regulations for dual-fuel vessel performance evaluation, considering the limitations of various maritime regulations.
Active helidecks systems (AHS) provide an effective solution scheme for the safe landing of helicopters on ships. This article proposes a novel adaptive antidisturbance prescribed performance control law of AHS subject to input saturation, ship motion-induced external disturbances. Specifically, we develop novel saturation-triggered boundaries to guarantee prescribed tracking error constraints under input saturation. This effectively addresses the control singularity issue inherent in traditional prescribed performance control, which occurs when input saturation causes the control error to exceed prescribed constraint boundaries. Subsequently, we design a continuous auxiliary dynamic system to further mitigate the effects of input saturation. Furthermore, leveraging the internal model principle and the periodic nature of ship motion, external disturbances are treated as the outputs of a linear exosystem with known structure but unknown parameters. These unknown parameters are then estimated using adaptive techniques, enabling asymptotic estimation of external disturbances. Building upon these developments and employing the backstepping design tool, we achieve adaptive antidisturbance stabilization of AHS. Both theoretical analysis and comparative simulations validate the proposed control law.
Jonathan Wuntu, Muhamad Dwisnanto Putro, Rendy Syahputra
Indonesia's marine ecosystems, part of the globally recognized Coral Triangle, are among the richest in biodiversity, requiring efficient monitoring tools to support conservation. Traditional fish detection methods are time-consuming and demand expert knowledge, prompting the need for automated solutions. This study explores the implementation of YOLOv10-nano, a state-of-the-art deep learning model, for real-time marine fish detection in Indonesian waters, using test data from Bunaken National Marine Park. YOLOv10's architecture, featuring improvements like the CSPNet backbone, PAN for feature fusion, and Pyramid Spatial Attention Block, enables efficient and accurate object detection even in complex environments. The model was evaluated on the DeepFish and OpenImages V7-Fish datasets. Results show that YOLOv10-nano achieves a high detection accuracy with mAP50 of 0.966 and mAP50:95 of 0.606 while maintaining low computational demand (2.7M parameters, 8.4 GFLOPs). It also delivered an average inference speed of 29.29 FPS on the CPU, making it suitable for real-time deployment. Although OpenImages V7-Fish alone provided lower accuracy, it complemented DeepFish in enhancing model robustness. Overall, this study demonstrates YOLOv10-nano's potential for efficient, scalable marine fish monitoring and conservation applications in data-limited environments.
Timo Kehrer, Robert Haines, Guido Juckeland
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Anecdotal evidence suggests that Research Software Engineers (RSEs) and Software Engineering Researchers (SERs) often use different terminologies for similar concepts, creating communication challenges. To better understand these divergences, we have started investigating how SE fundamentals from the SER community are interpreted within the RSE community, identifying aligned concepts, knowledge gaps, and areas for potential adaptation. Our preliminary findings reveal opportunities for mutual learning and collaboration, and our systematic methodology for terminology mapping provides a foundation for a crowd-sourced extension and validation in the future.
The Southeast Asia maritime architectural practice characteristic of its geopolitical configuration is an ancient-and- modern palimpsest of maritime genius made of incremental revisionist and intersecting premodern technocultural paradigms before and after transforming into contemporary industrial modes in ship-construction. In this essay, I seek to map the longue durée of the shipbuilding sector in Southeast Asia focusing on an evolutionary chain that connects autochthonous waterborne conveyances, the balangay and jong that epitomize native epistemologies mobility with highly mechanised infrastructures in urban-industrial combined centre specific to Singapore, Ho Chi Minh as well as Subic Bay. Triangulating material culture studies, historiographical inquest, and econometric datasets at method level the inquiry deconstructs the dialect of endogenous innovation and exogenous imposition through which has enacted the ontogenesis of maritime shipbuilding practices from below. Local craftsmen and transoceanic mercantile circuits as antagonistic imbrications, the socio-technological sedimentations resulting from instances of colonial entanglement will be central to the examination. Through this lens, the paper problematizes maritime engineering's tradition-bound teleologies of progress and presents instead a heterochronic model of precolonial, colonial and postcolonial in iterative reinvention and syncretic accretion. Moreover, the investigation traces epistemic infrastructures underpinning maritime archives and representations engaging with the epistemological work made possible in erecting archaeological objects, ethnographic narratives and macroeconomic indicators on shore. Via this analytical lens, the study places Southeast Asia not as a just-peripheral or derivative site of shipbuilding breakthroughs but rather for epistemic node in the capitalist maritime-industrial complex: a nexus where geostrategic urgencies come into convergence with tech-cultural hybridity. This means that the paper sets regaining its status in global supply chains and oceanographic geopolitical configurations in its regionally enduring but also contemporary renaissance as a node for naval architectural production, questioning both the historical base and current triumph. Constructing premodern heritage of maritime with the vamp of late-capitalist industrial rationality in Southeast Asia shipbuilding seems as a necessary vector, if we want to ask broader questions about technological sovereignty; regional integration or the material infrastructures of transnational capitalism.
Marine vessel design plays a key role in optimizing global trade, environmental sustainability, and technological advancements in naval architecture. However, a comprehensive review of research trends, key advancements, and future directions in sustainable marine vessel design has been lacking. This study addresses this gap by conducting a bibliometric analysis of 1701 publications from the Web of Science Core Collection database from 2000 to 2024. Using CiteSpace and VOSviewer, this research explores global research patterns, key institutions, and the evolution of thematic areas in sustainable marine vessel design over the last 24 years. The results reveal significant contributions from countries such as China, the USA, and South Korea, emphasizing sustainable technologies, safety, structural integrity, and intelligent systems in vessel design. Key research hotspots include “optimization”, “modeling”, “simulation”, and “computational fluid dynamics (CFD)”, reflecting the growing use of advanced technologies to improve vessel efficiency, environmental sustainability, and safety. This study also highlights the importance of interdisciplinary collaboration involving structural engineering, fluid mechanics, materials science, and environmental science. By mapping the historical landscape, current dynamics, and future directions of sustainable marine vessel design, this study aims to provide a foundation for advancing scientific discourse and practical applications in this field.