Knowledge

Media: Paper

paper

Adaptive Observer for Nonlinearly Parameterized Hammerstein System With Sensor Delay—Applied to Ship Emissions Reduction

Nielsen, Kræn Vodder; Blanke, Mogens; Eriksson, Lars

Taking offspring in a problem of ship emission reduction by exhaust gas recirculation control for large diesel engines, an underlying generic estimation challenge is formulated as a problem of joint state and parameter estimation for a class of multiple-input single-output Hammerstein systems with first-order dynamics, sensor delay, and a bounded time-varying parameter in the nonlinear part. This brief suggests a novel scheme for this estimation problem that guarantees exponential convergence to an interval that depends on the sensitivity of the system. The system is allowed to be nonlinear, parameterized, and time dependent, which are characteristics of the industrial problem we study. The approach requires the input nonlinearity to be a sector nonlinearity in the time-varying parameter. Salient features of the approach include simplicity of design and implementation. The efficacy of the adaptive observer is shown on simulated cases, on tests with a large diesel engine on test bed, and on tests with a container vessel.

IEEE Transactions on Control Systems Technology ( Volume: 26, Issue: 4, July 2018) / 2017
Go to paper
paper

Adopting a Quadruple Bottom Line approach for assessing offshore energy hubs: A proposal based on industrial insights and expert reviews

Marianne Petersen, Shi You, Aidan Cronin & Henrik Bach Mortensen

This study investigates the critical parameters necessary for evaluating large-scale renewable offshore energy hubs, based on insights from industry experts. Using a Multi-Criteria Decision Analysis methodology, the experts emphasized that, in their view, technical and economic parameters rank higher than environmental and societal considerations when evaluating large-scale renewable offshore projects, including green hydrogen production. Environmental and societal parameters should not be neglected, but they ought to be evaluated outside this assessment framework. This could refer to the environmental impact assessment already in use. These findings provide a foundation for evolving the traditional Triple Bottom Line theory into a Quadruple Bottom Line approach by incorporating technical parameters alongside economic, social, and environmental factors, while addressing the specific challenges of offshore energy hubs. Among all the parameters ranked across the four domains, the top 15 were exclusively techno-economic, with technical and economic scores averaging 4.5 and 4.3 out of 5, respectively. In contrast, societal and environmental scores averaged below 3.0. To ensure the successful deployment of offshore energy hubs, a stepwise approach is recommended to manage complexity, reduce risks, and support scalable solutions. This approach aims to align the needed industrial parameters with the demands of the energy transition.

Energy Reports / 2025
Go to paper
paper

Adopting Ecosystem and Justice Approaches in Deep-Sea Mining as a Paradigm Shift for Sustainable Development: Norway’s Arctic Case in Multi-level Ocean Governance

Sandra Cassotta, Despoina Anastasiadou Galva & Nelson F. Coelho

This article explores how adopting a combined ecosystem and justice approach to deep-sea mining (DSM)-particularly in vulnerable regions like the Arctic-would constitute a paradigm shift in ocean environmental law and governance. Such a shift would move ocean governance beyond fragmented, technocratic, and resource-driven frameworks toward an integrated, equitable, and sustainability-centered regime grounded in ecological integrity, social justice, and respect for human rights and local traditions.

Oil, Gas and Energy Law / 2025
Go to paper
paper

Advance in wave reflection estimation for rubble mound breakwaters: The importance of the relative water depth

Pilar Díaz-Carrasco, Mads Røge Eldrup & Thomas Lykke Andersen

The main objective of this research is to present an improved and more accurate formula to estimate the reflection coefficient (K R ) for rubble mound breakwaters. Physical model tests were performed for this purpose and existing data was also considered. The evaluation of existing prediction formulas for K R based on the Iribarren number (ξ) shows that the scatter in the experimental results increases with increasing ξ. This is caused by the wavelength having greater influence on the reflection than the wave height and thus the use of the wave steepness is inappropriate. The influence of potentially dimensionless parameters on the wave reflection from literature was analyzed. The major dimensionless parameters were found to be the relative water depth (h/L) and the structure front slope angle (α). Hence, a formula to estimate wave reflection for rubble mound breakwaters based on these two parameters is proposed.

Coastal Engineering / 2021
Go to paper
paper

Advanced solid-state lithium battery and its safety

Zhaoyang Zhao, Haitao Hu, Zhengyou He, Hongyi Zhu, Pooya Davari, Frede Blaabjerg

Solid-state lithium battery (SSLB) is considered as the most potential energy storage device in the next generation energy system due to its excellent safety performance. However, there are still intimidating safety issues for the SSLB, due to it being still in the development stage. This paper gives an overview of the safety of SSLBs. First, advanced solid-state battery techniques are introduced. Second, the safety issues of SSLBs are discussed. Then, the safety enhancement techniques are provided. Finally, future research opportunities are presented. This paper aims to provide a reference for researchers in the fields of electronic and electrical engineering who want to make some efforts in SSLB safety.

CPSS Transactions on Power Electronics and Applications (CPSS TPEA) / 2023
Go to paper
paper

Advances in Thoughts and Approaches for Transport and Logistics Systems Performance Evaluation

Aseem Kinra*, Füsun Ülengin, Werner Rothengatter

Policy makers often need support for evaluating transportation and logistics system performance, and for understanding the long-term effects and relationships between transportation investments, system performance and economic growth, both at the regional and national levels (Banister and Berechman, 2001; Laird and Venables, 2017). The economic evaluation of system performance, risks and barriers come paradigmatically together during the processes of transport systems investment choice decision

Transport Policy / 2022
Go to paper
paper

Advancing coordination in critical maritime infrastructure protection: Lessons from maritime piracy and cybersecurity

Tobias Liebetrau, Christian Bueger

Critical maritime infrastructure protection has become a priority in ocean governance, particularly in Europe. Increased geopolitical tensions, regional conflicts, and the Nord Stream pipeline attacks in the Baltic Sea of September 2022 have been the main catalysts for this development. Calls for enhancing critical maritime infrastructure protection have multiplied, yet, what this implies in practice is less clear. This is partially a question of engineering and risk analysis. It also concerns how the multitude of actors involved can act concertedly. Dialogue, information sharing, and coordination are required, but there is a lack of discussion about which institutional set ups would lend themselves. In this article, we argue that the maritime counter-piracy operations off Somalia, as well as maritime cybersecurity governance hold valuable lessons to provide new answers for the institutional question in the critical maritime infrastructure protection agenda. We start by clarifying what is at stake in the CMIP agenda and why it is a major contemporary governance challenge. We then examine and assess the instruments found in maritime counter-piracy and maritime cybersecurity governance, including why and how they provide effective solutions for enhancing critical maritime infrastructure protection. Finally, we assess the ongoing institution building for CMIP in Europe. While we focus on the European experience, our discussion on designing institutions carries forward lessons for CMIP in other regions, too.

International Journal of Critical Infrastructure Protection / 2024
Go to paper
paper

ADVANTAGES AND LIMITATIONS OF USING CAMERAS ON SMALL, LOW-COST ROVS FOR SEABED MONITORING

Amanda Frederikke Irlind, Alex Jørgensen, Jonathan Eichild Schmidt, Anders Skaarup Johansen, Thomas B. Moeslund, Karen Ankersen Sønnichsen & Niels Madsen

Monitoring methods, such as seabed bottom-towed cameras, sediment grabs, and benthic sledges, have limitations in spatial coverage, cause seabed disturbance, are restricted to soft-bottom substrates, and offer low flexibility for marine seabed monitoring. In this study, we investigate the potential of a non-invasive and simple underwater remotely operated vehicle (ROV) to enhance marine seabed monitoring. A tethered ROV equipped with a GoPro camera was deployed in three areas of Skagerrak at depths from 15-34 m to assess accuracy in species identification and substrate classification identified from still frames. The quality of still frames varied between areas due to turbidity, motion blur, and marine snow, which reduced the number of high-quality frames by approximately 20%. Classification of substrates and taxa identification were possible in the remaining still frames. Two different substrates were detected: sand and stone reef. Stone reefs had a lower occurrence compared to sand. A total of 10 taxa were detected in the two substrate types. The highest abundance was observed in the stone reef substrate compared to the sand substrate. Identification at the species level was limited due to the quality of the still frames, which affected the detectability of morphological traits. This study demonstrates that a widely accessible ROV can be used for marine monitoring. The ROV can be used in different substrates, and still frames provide valuable information on species composition, which can enhance the replicability of monitoring programs.

Journal of Ocean Technology / 2024
Go to paper
paper

AEGIS: Advanced, efficient and green intermodal systems

Ornulf Jan Rodseth*, Harilaos N. Psaraftis, Stefan Krause, Jesper Raakjr, Nelson F. Coelho

The European maritime transport policy recognizes the importance of the waterborne transport systems as key elements for sustainable growth in Europe. A major goal is to transfer more than 50% of road transport to rail or waterways within 2050. However, waterways are at a disadvantage as they normally depend on transhipment and land transport to and from final destination. To meet this challenge we need a completely new approach to short sea and inland waterways shipping in Europe. This needs to include ships as well as ports and the digital information exchanges between them. A key element in this is automation of ships, ports and administrative tasks. The AEGIS project has been funded by the EU Commission to develop new knowledge and technology to address this challenge.

IOP Conference Series: Materials Science and Engineering / 2020
Go to paper
paper

Age and nationality in relation to injuries at sea among officers and non-officers: a study based on contacts from ships to Telemedical Assistance Service in Denmark.

Kimmo Herttua, Stine Gerdøe-Kristensen, Jan Vork, Jesper Bo Nielsen

Objectives Characterisation of worker injuries on board merchant ships is modest. Using telemedical service contacts in Denmark, we describe the worker injuries patterns and factors related to injury incidence. Methods The data for this study were based on contacts (n=1401) from ships to Telemedical Assistance Service (TMAS) in Denmark in 2004–2014, which were supplemented with data on the annual estimation of all seafarers from the Danish Maritime Authority (n=73 336). The final data included information on broad age groups, occupation and nationality. The outcomes were injuries from any cause and six broad categories of injuries characterised by anatomic location or type of injury. Results During the observation period of 11 years, there were 1401 contacts to TMAS due to injuries, of which 36% were in upper limb, 18% in lower limb and 13% in the head. Age-adjusted incidence rates for all injuries varied between 13.6 and 26.8 incidences per 1000 person-years in 2004–2014. In most types of injuries, younger and older seafarers had higher risk for injuries than seafarers aged 30–49 years. Depending on the type of injury, non-officers had threefold to fivefold increased odds of injuries compared with officers, the risk being highest for head injuries with an OR of 5.00 (95% CI 3.19 to 7.83). Non-officers from the European Union (EU) had higher risk in most types of injuries than non-officers from outside the EU, whereas the pattern of this risk was inverse among officers. Conclusions These findings suggest that non-officers and European seafarers have an increased risk for several types of injuries on board Danish-flagged merchant ships. Additionally, age affected risk with the younger (<30 years) and older (>50 years) seafarers having increased risk.

BMJ Open / 2019
Go to paper