Cyber-resilience is an increasing concern for autonomous navigation of marine vessels. This paper scrutinizes cyber-resilience properties of marine navigation through a prism with three edges: multiple sensor information fusion, diagnosis of not-normal behaviours, and change detection. It proposes a two-stage estimator for diagnosis and mitigation of sensor signals used for coastal navigation. Developing a Likelihood Field approach, the first stage extracts shoreline features from radar and matches them to the electronic navigation chart. The second stage associates buoy and beacon features from the radar with chart information. Using real data logged at sea tests combined with simulated spoofing, the paper verifies the ability to timely diagnose and isolate an attempt to compromise position measurements. A new approach is suggested for high level processing of received data to evaluate their consistency, which is agnostic to the underlying technology of the individual sensory input. A combined generalized likelihood ratio test using both parametric Gaussian modelling and Kernel Density Estimation is suggested and compared with a detector using only either of two. The paper shows how the detection of deviations from nominal behaviour is possible when the navigation sensor is under attack or defects occur.
Acknowledgments: I thank Amanda Bille, Anna Land, Attila Marton, Britta Gammelgaard, Carl Marcus Wallenburg, Christian Durach, Christian Hendriksen, Christian Huber, Dane Pflueger, Elise Berlinski, Florian Kock, Frank Fürstenberg, Helen Peck, Ida Schrøder, Ingo Zettler, Jan Mouritsen, Jane Lister, Jennifer Rogan, Johan Lundin, Kamilla Barat, Lisa Paulsen, Lorraine van Halewijn, Marin Jovanovic, Michael Herburger, Paola Trevisan, Philip Beske-Janssen, Regina Brogna, Stefano Ponte, and Thomas Johnsen for their helpful suggestions and comments. I also thank Journal of Supply Chain Management’s editorial team, especially Mark Pagell and the anonymous associate editor, for their exceptionally constructive and thoughtful guidance. In particular, I thank Günther Metzger and Jean François Bianco, who have been very inspirational throughout my thought process. This research resulted from a collaboration between Copenhagen Business School and Nordakademie.
The costs of buying tonnage – whether new built or second hand – are so high that most Owners will need the assistance of Financers in order to be able to make the purchase. This raises several legal questions regarding ship’s finance. This article will provide a discussion of certain aspects of ships’ finance under Danish Law relevant to the charterparty trade.
The factual starting point for the paper is that a vessel is working in or intended to work in the charterparty trade, most particularly under long term time charterparties or Contracts of Affreightment. In such a situation, we find a tri-party relationship between the Financers, the Owners and the Charterers. When things are well, the interests of these three parties are on a par. The Charterers wish to use the vessel in order to make a profit, enabling them to pay the Owners. The Owners, receiving the hire or freight, are able to pay the crew, maintain the vessel and pay the Financers. However, the moment the financial stability of the Owner or the Charterer is threatened, the three parties will tend to have conflicting interests. The Financers, if unpaid, may wish to sell the vessel in order to cover at least some of their losses. The Charterers may wish to continue the use of the vessel, which may be inconsistent with a (forced) sale. Alternatively, the Charterers may wish to be freed of their obligations under the charterparty if the Owner enters into receivership or other types of insolvency proceedings. They may not be comfortable with e.g. having the Owners estate in bankruptcy running the vessel. And ultimately the Owners estate may wish to reconstruct the company in order to stay in business, for which end keeping the vessel as an asset and the income flowing from a (continued) charterparty may be a precondition.
The paper will discuss the problem with the starting point in Danish law on the subject, and investigate whether Danish law is apt to protect the conflicting interests of the three parties. However, the paper will make comparisons to other laws, mainly English law and Norwegian law. Also, the paper will discuss the general problems with the definitions of how a working vessel should generally be considered in the eyes of the law (is it simply any piece of chattels or is it more akin to a whole production facility?) and as well as whether the service provided by both owners and charterers under a charterparty should be considered personal or generic. Thus, although the paper uses Danish law as a starting point, it provides points of discussion of more general interest.
The paper ultimately concludes that Danish law does provide an adequate protection and balancing of the interest of the parties, but that uncertainties and the general inaccessibility of the law must be considered to restrict its use to the full – to the detriment of market interests.
The shipping industry is associated with approximately three quarters of all world trade. In recent years, the sustainability of shipping has become a public concern, and various emissions control regulations to reduce pollutants and greenhouse gas (GHG) emissions from ships have been proposed and implemented globally. These regulations aim to drive the shipping industry in a low-carbon and low-pollutant direction by motivating it to switch to more efficient fuel types and reduce energy consumption. At the same time, the cyclical downturn of the world economy and high bunker prices make it necessary and urgent for the shipping industry to operate in a more costeffective way while still satisfying global trade demand. As bunker fuel bunker (e.g., heavy fuel oil (HFO), liquified natural gas (LNG)) consumption is the main source of emissions and bunker fuel costs account for a large proportion of operating costs, shipping companies are making unprecedented efforts to optimize ship energy efficiency. It is widely accepted that the key to improving the energy efficiency of ships is the development of accurate models to predict ship fuel consumption rates under different scenarios. In this study, the ship fuel consumption prediction models presented in the literature (including the academic literature and technical reports, which are a typical type of “grey literature”) are reviewed and compared, and models that optimize ship operations based on fuel consumption prediction results are also presented and discussed. Current research challenges and promising research questions on ship performance monitoring and operational optimization are identified.
Maintaining the condition of a vessel and its equipment guarantees the scheduled completion of voyages and the safety of the crew.
This paper presents condition monitoring techniques for early detection of faults related to piston rings in remote cylinders of two-stroke marine diesel engines. Operational sensor data from the main engine of a container ship are provided by a shipping company.
A graphical approach complimented by correlation heatmaps and feature importance from gradient boosting trees are used for feature selection. Support Vector Machine, Random Forest and Extreme Gradient Boosting Trees are tested for residual generation from the nominal behavior.
The residual time series gives a good indication of the degradation of the system and can be used for alarm raising under strict rules. It is proven that the proposed method could alert the engine crew of a change in the condition of the piston rings much earlier than existing methods.
Unmanned surface vehicles (USVs) are increasingly appealing for gathering metocean data, including directional sea spectra. This paper presents new developments towards estimating the response amplitude operators (RAOs) of surface vehicles equipped with inertial sensors. The novel approach undertakes the data-driven estimation of vehicle models of the wave-induced heave, roll, and pitch motion dynamics, as required to perform subsequent seakeeping computations. Specifically, a genetic algorithm executes the calibration of available closed-form RAOs for a simplified geometry. The algorithm makes a population of model-fitting parameters evolve towards minimising discrepancies between the predicted and measured response spectra in stationary operational conditions. Trust in the model is eventually increased by screening and merging the best-fitting solutions. Resulting response predictions using high-resolution spectral wave data for the AutoNaut USV demonstrate satisfactory accuracy and robustness in heave and pitch but a worse fidelity in roll, thereby motivating follow-up studies to improve the estimation of roll RAOs.
Hydrogen is believed as a promising energy carrier that contributes to deep decarbonization, especially for the sectors hard to be directly electrified. A grid-connected wind/hydrogen system is a typical configuration for hydrogen production. For such a system, a critical barrier lies in the poor cost-competitiveness of the produced hydrogen. Researchers have found that flexible operation of a wind/hydrogen system is possible thanks to the excellent dynamic properties of electrolysis. This finding implies the system owner can strategically participate in day-ahead power markets to reduce the hydrogen production cost. However, the uncertainties from imperfect prediction of the fluctuating market price and wind power reduce the effectiveness of the offering strategy in the market. In this paper, we proposed a decision-making framework, which is based on data-driven robust chance constrained programming (DRCCP). This framework also includes multi-layer perception neural network (MLPNN) for wind power and spot electricity price prediction. Such a DRCCP-based decision framework (DDF) is then applied to make the day-ahead decision for a wind/hydrogen system. It can effectively handle the uncertainties, manage the risks and reduce the operation cost. The results show that, for the daily operation in the selected 30 days, offering strategy based on the framework reduces the overall operation cost by 24.36%, compared to the strategy based on imperfect prediction. Besides, we elaborate the parameter selections of the DRCCP to reveal the best parameter combination to obtain better optimization performance. The efficacy of the DRCCP method is also highlighted by the comparison with the chance-constrained programming method.
The Ghana National Single Window has become the focus of attention over its potential to move goods swiftly. However, since its inception in 2002, the controversies surrounding the implementation suggest issues beyond trade facilitation. The Information Systems literature primarily ascribes the controversies to resistance to technology. By adopting the Soft Systems Methodology (SSM) as a learning process for understanding port stakeholders' relations and attitudes, we explore the controversies to determine the meanings port stakeholders attribute to them. We combined SSM with interviews, media content analysis and focus groups made possible by snowballing. The responses were analyzed using rich pictures and validated through a conceptual model. The results reveal a fragmented government where ministries, agencies, and personalities assert power in single window implementation through I.T. vendor contracts. The situation results in a high cost of doing business at the port for shippers due to non-transparent and questionable contracts. The public's attitude towards the controversies reflects fears, hopes and expectations and legitimate concerns about important political and social goals. Using SSMs focus on relations and attitudes, we can document how controversies attributed to new technology is not a question of technology but of perceived political interference.
The purpose of this paper is to assess the status and prospects of the decarbonization of maritime transport. Already more than two years have passed since the landmark decision of the International Maritime Organization (IMO) in April 2018, which entailed ambitious targets to reduce greenhouse gas (GHG) emissions from ships. The paper attempts to address the following three questions: (a) where do we stand with respect to GHG emissions from ships, (b) how is the Initial IMO Strategy progressing, and (c) what should be done to move ahead? To that effect, our methodology includes commenting on some of the key issues addressed by the recently released 4th IMO GHG study, assessing progress at the IMO since 2018, and finally identifying other issues that we consider relevant and important as regards maritime GHG emissions, such as for instance the role of the European Green Deal and how this may interact with the IMO process. Even though the approach of the paper is to a significant extent qualitative, some key quantitative and modelling aspects are considered as well. On the basis of our analysis, our main conjecture is that there is not yet light at the end of the tunnel with respect to decarbonizing maritime transport.
The purpose of this paper is to assess the status and prospects of the decarbonization of maritime transport. Already more than two years have passed since the landmark decision of the International Maritime Organization (IMO) in April 2018, which entailed ambitious targets to reduce greenhouse gas (GHG) emissions from ships. The paper attempts to address the following three questions: (a) where do we stand with respect to GHG emissions from ships, (b) how is the Initial IMO Strategy progressing, and (c) what should be done to move ahead? To that effect, our methodology includes commenting on some of the key issues addressed by the recently released 4th IMO GHG study, assessing progress at the IMO since 2018, and finally identifying other issues that we consider relevant and important as regards maritime GHG emissions, such as for instance the role of the European Green Deal and how this may interact with the IMO process. Even though the approach of the paper is to a significant extent qualitative, some key quantitative and modelling aspects are considered as well. On the basis of our analysis, our main conjecture is that there is not yet light at the end of the tunnel with respect to decarbonizing maritime transport.