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Sales strategy selection for liner companies under shipping e-commerce considering canvassing ability competition

Heying Sun, Qingcheng Zeng, Jasmine Siu Lee Lam*, Shuyi Pu, Chenrui Qu

The rapid growth of e-commerce applications has promoted the establishment of shipping e-commerce channels by many liner companies in addition to their existing traditional Non-vessel operating common carrier (NVOCC) channel. Unlike NVOCC channels, shipping e-commerce channels guarantee shippers the availability of contracted container slots. However, some problems arise, including the competition with NVOCC channels, shipping slot sales’ risk, and the increasing liner companies’ costs. Therefore, this paper addresses optimal sales strategy selection in the liner transportation industry, including a single traditional NVOCC channel (TN) strategy, and a dual channel with both e-commerce and NVOCC channels (EN) strategy. Two contract scheme models are constructed considering the channel competition on canvassing ability, overselling behavior, demand fluctuation, and the limited liner vessel capacity. Findings show that the impact of overselling behavior on the profit under the EN and TN is not always negative, which is related to the shipping capacity and probability of the high canvassing ability. Comparative analyses reveal that the EN is dominant if the unit overselling compensation cost varies small. Meanwhile, the TN is profitable if the unit overselling compensation cost increases and the canvassing cost of e-commerce channel exceeds a certain value. Otherwise, the selection of sales strategy relies on the arrival rate, the canvassing cost of the e-commerce channel and shipping capacity. The results offer new insights to both theoretical research on container slot sales and the practical selection of sales strategy since shipping e-commerce has changed the slot selling mode in the container shipping industry, which could also enhance the competitiveness of liner companies in the container shipping industry.

European Journal of Operational Research / 2025
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Reliability-Oriented Control of Battery Energy Storage Systems

Tahir, Muhammad Usman (PI)Blaabjerg, Frede (Supervisor)Sangwongwanich, Ariya (Supervisor)Stroe, Daniel-Ioan (Supervisor)

The importance of reliable battery energy storage systems (BESS) is key to the sustainability of many applications such as renewable power, smart grids, and electric vehicles (EVs). Due to decreasing cost and maturing technology, the Li-ion batteries are now widely used for grid-level storage, grid support for improved power quality, integration with photovoltaic systems, and EV applications. A Li-ion battery pack typically comprises Li-ion cells connected in a suitable combination of series and parallel structure. A battery management system (BMS) is required for charging and discharging, monitoring the current and voltage of each cell or string, battery protection, and temperature control. The system's reliability depends on the BESS reliability and is affected by many factors, including temperature, C-rate, DOD. This research aims to improve BESS reliability by using accurate lifetime modelling for various BMS and converter topologies to identify real-time BESS health and ensure reliability through a suitable control strategy. In particular, the reliability of the BESS for centralized, modularised, distributed, and decentralized topology will be explored along with its cost-reliability trade-off. I will focus on control strategies for optimizing BESS reliability for different applications.

Not yet published / 2025
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Scratched surface: Quantifying the impact and evaluating underwater cleaning efficacy on fouling release coatings

Shujie Lin, Huichao Bi*, Claus Erik Weinell, Kim Dam-Johansen

Fouling release coatings (FRCs) can become damaged and diminished over exposure. Quantifying adverse effect of scratches on FRCs is crucial for damage control. This study investigated the effect of four pre-defined scratches on the re-fouling of a silicone-based FRC (SiFR) undergoing underwater cleaning utilizing a novel automated underwater cleaning system (AUCS). Moreover, barnacle adhesion and coating detachment formation of scratched SiFR were evaluated. Field testing at the CoaST Maritime Test Centre (CMTC) demonstrated that the scratches varying in depths and widths can significantly affect the biofouling behavior and cleaning efficiency of SiFR surface. For wide scratches (i.e. 3-mm-wide), hard fouling (e.g. barnacles, mussels) was more prone to accumulate, and underwater cleaning was effective in preventing hard fouling but not soft fouling on SiFR surface. Additionally, the re-fouling and cleaning difficulty of hard fouling increased with the depth of wide scratches. For narrow scratches (i.e. <50-μm-wide), SiFR was primarily attached by soft fouling (e.g. biofilm, algae), and underwater cleaning performed positive fouling resistance of algae but not biofilm on SiFR surface. Besides, algae became difficult to remove with the depth of narrow scratches. Notably, biweekly cleaning proved to be highly effective in biofouling control of SiFR with narrow and shallow scratches.

Ocean Engineering / 2025
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A critical review of challenges and opportunities for the design and operation of offshore structures supporting renewable hydrogen production, storage, and transport

Claudio Alexis Rodríguez Castillo*, Baran Yeter, Shen Li, Feargal Brennan, Maurizio Collu

The climate emergency has prompted rapid and intensive research into sustainable, reliable, and affordable energy alternatives. Offshore wind has developed and exceeded all expectations over the last 2 decades and is now a central pillar of the UK and other international strategies to decarbonise energy systems. As the dependence on variable renewable energy resources increases, so does the importance of the necessity to develop energy storage and nonelectric energy vectors to ensure a resilient whole-energy system, also enabling difficult-to-decarbonise applications, e.g. heavy industry, heat, and certain areas of transport. Offshore wind and marine renewables have enormous potential that can never be completely utilised by the electricity system, and so green hydrogen has become a topic of increasing interest. Although numerous offshore and marine technologies are possible, the most appropriate combinations of power generation, materials and supporting structures, electrolysers, and support infrastructure and equipment depend on a wide range of factors, including the potential to maximise the use of local resources. This paper presents a critical review of contemporary offshore engineering tools and methodologies developed over many years for upstream oil and gas (O&G), maritime, and more recently offshore wind and renewable energy applications and examines how these along with recent developments in modelling and digitalisation might provide a platform to optimise green hydrogen offshore infrastructure. The key drivers and characteristics of future offshore green hydrogen systems are considered, and a SWOT (strength, weakness, opportunity, and threat) analysis is provided to aid the discussion of the challenges and opportunities for the offshore green hydrogen production sector.

Wind Energy Science / 2024
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Using biophysical modelling and marine connectivity to assess the risk of natural dispersal of non-indigenous species to comply with the Ballast Water Management Convention

Flemming Thorbjørn Hansen*, Ane Pastor, Asbjørn Christensen, Frank Stuer-Lauridsen

The introduction of Marine Non-Indigenous Species (NIS) poses a significant threat to global marine biodiversity and ecosystems. To mitigate this risk, the Ballast Water Management Convention (BWMC) was adopted by the UN International Maritime Organisation (IMO), setting strict criteria for discharges of ballast water. However, the BWMC permits exemptions for shipping routes operating within a geographical area, known as a Same-Risk-Area (SRA). An SRA can be established in areas where a risk assessment (RA) can conclude that the spread of NIS via ballast water is low relative to the predicted natural dispersal. Despite the BWMC's requirement for RAs to be based on modelling of the natural dispersal of NIS, no standard procedures have been established. This paper presents a methodology utilizing biophysical modelling and marine connectivity analyses to conduct SRA RA and delineation. Focusing on the Kattegat and Øresund connecting the North Sea and Baltic Sea, we examine two SRA candidates spanning Danish and Swedish waters. We provide an example on how to conduct an RA including an RA summary, and addressing findings, challenges, and prospects. Our study aims to advance the development and adoption of consistent, transparent, and scientifically robust SRA assessments for effective ballast water management.

Biological Invasions / 2024
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Extreme nonlinear ship response estimations by active learning reliability method and dimensionality reduction for ocean wave

Tomoki Takami*, Masaru Kitahara, Jørgen Juncher Jensen, Sadaoki Matsui

An efficient extreme ship response prediction approach in a given short-term sea state is devised in the paper. The present approach employs an active learning reliability method, named as the active learning Kriging + Markov Chain Monte Carlo (AK-MCMC), to predict the exceedance probability of extreme ship response. Apart from that, the Karhunen-Loève (KL) expansion of stochastic ocean wave is adopted to reduce the number of stochastic variables and to expedite the AK-MCMC computations. Weakly and strongly nonlinear vertical bending moments (VBMs) in a container ship, where the former only accounts for the nonlinearities in the hydrostatic and Froude-Krylov forces, while the latter also accounts for the nonlinearities in the radiation and diffraction forces together with slamming and hydroelastic effects, are studied to demonstrate the efficiency and accuracy of the present approach. The nonlinear strip theory is used for time domain VBM computations. Validation and comparison against the crude Monte Carlo Simulation (MCS) and the First Order Reliability Method (FORM) are made. The present approach demonstrates superior efficiency and accuracy compared to FORM. Moreover, methods for estimating the Mean-out-crossing rate of VBM based on reliability indices derived from the present approach are proposed and are validated against long-time numerical simulations.

Marine Structures / 2024
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New framework of port logistics in the post-COVID-19 period with 6th-generation ports (6GP) model

Paul Tae Woo Lee, Zhao Yu Song, Cheng Wei Lin, Jasmine Siu Lee Lam, Jihong Chen*

Since the outbreak of COVID-19, its impacts on the maritime transportation and logistics field have been multi-dimensional. In addition to the green shipping corridor proposed by the Clydebank Declaration in the United Kingdom in 2021, port digitalisation and decarbonisation of the maritime industry have become focal issues in the field. The industry needs a new framework to offset the negative impacts of the pandemic and to accommodate integrated technologies comprising of artificial intelligence (AI), blockchain, cloud systems, internet of things (IoT) and others, which have been applied to the industry. Having considered these circumstances, this paper aims to propose the 6th-generation ports model with smart port (6GP) as a new framework for the port logistics industry in the post-COVID-19 period. The proposed 6GP contributes to providing business development strategy and port development policy for stakeholders in the industry in the post-pandemic era reflecting focal challenges such as digitalisation, decarbonisation, sustainability and smart transformation. It also contributes to expanding port devolution theory from the fifth-generation ports (5GP) to 6GP.

Transport Reviews / 2024
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Operational cycles for maritime transportation: Consolidated methodology and assessments

Amandine Godet, George Panagakos, Michael Bruhn Barfod*, Elizabeth Lindstad

Operational cycles for maritime transportation is a new concept to improve the assessment of ships’ energy efficiency and offer benchmarking options among similar ship types and sizes. This work extends previous research to consolidate the methodology, bring more comprehensiveness, and provide a more holistic assessment of these operational cycles. The cycles are designed from noon reports from a fleet of around 300 container ships divided into eight size groups. The comparison between cycles derived from speed and draft with those based on main engine power identifies that the cycles based on speed and draft are more accurate and allow for estimating the Energy Efficiency Operational Index but require more data. The main-engine-power cycles are more effective in benchmarking through the Annual Efficiency Ratio. These cycles reduce the inherent variability of the carbon intensity indicator and present good opportunities as a benchmarking tool for strengthening the regulatory framework of international shipping.

Transportation Research Part D: Transport and Environment / 2024
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Logistics, politics and Berbera in the eye of an international storm

Finn Stepputat, Jethro Norman

A recently signed memorandum of understanding (MoU) between Ethiopia and Somaliland to develop the Port of Berbera and establish a naval base has sparked tensions and fears of conflict with Somalia. The MoU grants Ethiopia commercial access to Somaliland ports and a 20-kilometer lease for a naval base in exchange for Ethiopia's recognition of Somaliland's independence, drawing strong criticism from Somalia, which considers Somaliland part of its territory.

The article, ‘Logistics, Politics and Berbera in the Eye of an International Storm’ examines how the pursuit of economic development through logistics infrastructure can exacerbate political tensions and reignite historical conflicts. The Berbera corridor, envisioned as a pathway to peace, stability, and prosperity through economic interdependence, now underscores the potential for violent conflict inherent in modern logistics and infrastructure development. The case furthermore brings out the complex interplay of local, regional, and international interests at play in the Horn of Africa. Thus, the port's upgrade, intended to attract foreign investment and transform the area into a major trade hub, has intensified competition among Somaliland's clan lineages, inflamed historical tensions between Somalia and Ethiopia, and challenged the security and logistic interests of regional and global powers in the Red Sea and Western Indian Ocean.

The article is part of a special issue of Politique Africaine about the current armed conflicts in the Horn of Africa.

Politique Africaine / 2024
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From Mitigation to Adaptation: Problematizing Climate Change in the Maritime Transport Industry

Jan Stockbruegger, Christian Bueger

The literature on climate change in the maritime transport industry has grown rapidly in the last few years. Yet as the research agenda has progressed, scientific debates have become more isolated and fragmented, making it difficult to translate new findings into broader policy debates. This article draws on problematization methodology to help organize the scientific debate on maritime emissions and to identify analytical gaps and challenges. We argue that scholars investigate shipping's emission problem from four distinct analytical perspectives— (1) international laws and regulations, (2) markets and economics, (3) engineering and technology, and (4) authority and legitimacy. Each of these perspectives problematizes maritime emissions in specific ways, leading to different policies and strategies to address the problem. We call for better integrating these four literatures and highlight three crosscutting areas and problems for future research. First, developing institutions that facilitate market and engineering solutions; second, integrating climate mitigation and adaptation research; and third, focusing on justice concerns to ensure an equitable green transition in the maritime industry.

WIREs Climate Change / 2024
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