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PurposeThe purpose of this study is to investigate how transformational leadership influences firm performance through the sequential mediating roles of dynamic capabilities and frugal innovation. It also examines the moderating effects of entrepreneurial bricolage and environmental turbulence on these relationships.Design/methodology/approachDrawing on data from 412 Vietnamese small and medium-sized enterprises, this study applies a two-stage partial least squares structural equation modeling approach to test the proposed moderated serial mediation model.FindingsThe results reveal that transformational leadership significantly enhances dynamic capabilities, which in turn promote frugal innovation and ultimately improve firm performance. Dynamic capabilities partially mediate the relationship between transformational leadership and firm performance, while frugal innovation partially mediates the link between dynamic capabilities and performance. Moreover, entrepreneurial bricolage strengthens the positive effect of transformational leadership on frugal innovation and environmental turbulence amplifies the impact of dynamic capabilities on firm performance.Research limitations/implicationsThe study offers practical guidance for small and medium-sized enterprises operating in dynamic and resource-constrained environments by highlighting the roles of transformational leadership, dynamic capabilities and frugal innovation as critical drivers of adaptability and performance. It suggests that managers should foster leadership practices, encourage resource recombination and build capability portfolios to enhance strategic agility and innovation in turbulent markets.Originality/valueThis research extends the literature by introducing and empirically testing a novel moderated serial mediation model, linking transformational leadership to performance outcomes. It is among the first studies to examine the joint moderating effects of entrepreneurial bricolage and environmental turbulence, offering new insights into how leadership and organizational capabilities interact to drive resource-efficient innovation and performance in emerging markets.
PurposeThe study aimed to determine the compliance cost by comparing the net present value (NPV) of two sulphur abatement options, scrubber installation and very low sulphur oil (VLSFO) switching, with the case study of 907 TEUs and 3,000 TEU feeder container vessels while operating on distinct liner shipping routes.Design/methodology/approachThis study adopted quantitative methodology to compare the NPV associated with utilizing VLSFO vs. installing scrubbers to comply with IMO sulphur requirements on two case study feeder vessel scenarios. Besides, sensitivity assessment of the findings was performed under volatile fuel prices, loading factors, freight rates and scrubber costs.FindingsThe study outcome reveals that retrofitting the 907 TEU container vessel with a scrubber is more financially advantageous when the economic lifespan of the vessel is above 9.5 years. In contrast, VLSFO is the most economically viable option for 3,000 TEU vessels in its entire lifespan. Besides, fuel switching is a cost-effective alternative for 907 TEU vessels while the price spread between VLSFO and high sulphur fuel oil is 147 dollars or less.Research limitations/implicationsThis study primarily evaluated shipowners' compliance costs between fuel switching and scrubber installation. Alternative options - such as wind, solar, fuel cells, battery charging and alternative fuels - were excluded due to barriers including limited infrastructure, technological maturity, availability and high retrofitting costs.Practical implicationsThe outcomes will enhance the shipping industry's economic performance and competitiveness, reducing costs and risks and identifying opportunities for increased efficiency, innovation and market differentiation while preparing for future regulatory requirements.Originality/valueThe study's novelty lies in its quantitative assessment of sulphur abatement techniques tailored to feeder container vessels, with a focus on NPV under varied operational and market scenarios. Additionally, it provides actionable insights for ship owners ahead of the Mediterranean Sea emission control area enforcement, emphasizing mixed compliance strategies.
Decarbonization is an urgent global priority for the shipping sector, necessitating an inclusive transition in technology development, infrastructure investment, policy and regulatory reform, and stakeholders' engagement. While policy and legal frameworks play a critical role in this transition, policy barriers remain the most significant challenge, particularly for developing countries, as they can delay progress and increase costs. Vietnam, a coastal developing nation, is undergoing a green shipping transformation but faces multiple policy challenges. This study examines Vietnam's current policy and legal framework for shipping decarbonization, in the line with the International Maritime Organization's (IMO) policy approach. It employs normative legal and policy analysis, together with case study and comparative methods, to identify key deficiencies and barriers. To address these challenges, the study proposes an integrated strategy that incorporates four key perspectives - technical, operational, economic measures, and energy solutions - supported by economic instruments. It outlines three core policies and several tasks to drive decarbonization, focusing on enhancing energy efficiency, restructuring the national fleet, and transitioning to low- or zero-carbon fuels. These policies are tailored to Vietnam's small-scale shipping sector, providing clear implementation pathways and ensuring stakeholders' engagement. Additionally, this study serves as a model for developing countries undergoing decarbonization transitions toward a sustainable maritime industry.
Integrating switchable and multifunctional capabilities into metasurface structures has become a key area of research, particularly for terahertz (THz) frequencies, which pose significant challenges. In this work, we propose switchable wideband THz metasurfaces with versatile functionalities, including absorption, reflective polarization conversion, and transmissive polarization conversion, utilizing the phase-change material of vanadium dioxide (VO2). Simulations show that the proposed metasurface can dynamically switch from a broadband absorber and reflective cross-polarization conversion to a transmissive cross-polarization converter by controlling the phase of VO2. When VO2 is in its metallic state, the metasurface achieves efficient wideband absorption for backward incident waves in the range of 1.63 to 4.55 THz with absorption exceeding 0.9. It also exhibits reflective polarization conversion for forward linearly polarized waves over a broad frequency range of 1.8-4.65 THz, with a polarization conversion ratio (PCR) greater than 0.9. Switching VO2 to its insulating state enables a broadband transmissive polarization converter for forward y-polarized incidence in the 1.0-5.5 THz range, achieving PCR > 0.99 and asymmetric transmission efficiency > 0.45 within a 2.3 THz bandwidth. Wideband performance is maintained over a broad range of incident angles. The proposed switchable metasurface offers potential for advanced smart THz applications with diverse functionalities.
Electroencephalography (EEG) underpins neuroscience, clinical neurophysiology, and brain-computer interfaces (BCIs), yet pronounced inter- and intra-subject variability limits reliability, reproducibility, and translation. This systematic review studies that quantified or modeled EEG variability across resting-state, event-related potentials (ERPs), and task-related/BCI paradigms (including motor imagery and SSVEP) in healthy and clinical cohorts. Across paradigms, inter-subject differences are typically larger than within-subject fluctuations, but both affect inference and model generalization. Stability is feature-dependent: alpha-band measures and individual alpha peak frequency are often relatively reliable, whereas higher-frequency and many connectivity-derived metrics show more heterogeneous reliability; ERP reliability varies by component, with P300 measures frequently showing moderate-to-good stability. We summarize major sources of variability (biological, state-related, technical, and analytical), review common quantification and modeling approaches (e.g., ICC, CV, SNR, generalizability theory, and multivariate/learning-based methods), and provide recommendations for study design, reporting, and harmonization. Overall, EEG variability should be treated as both a practical constraint to manage and a meaningful signal to leverage for precision neuroscience and robust neurotechnology.
