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    Efficiency and Sustainability of Bangkok Port Barge Transport: A Comparative Analysis with Feeder Vessels Under Thailand's Logistics Strategy
    (2025-06-01)
    Nakchatree, Kanokporn
    ;
    Prabnasak, Jaruwit
    This study assessed the effectiveness and sustainability of using barge versus feeder vessels to transport containerized cargo to Bangkok Port, Thailand. A survey of 387 stakeholders in marine logistics was conducted from October to December 2024. Multiple regression analysis (MRA) showed that cost-effectiveness, environmental impact, and operational flexibility primarily influenced transport mode choice, explaining 56.2% of the variance. Cost-effectiveness emerged as the key factor, while environmental impact was the strongest predictor of perceived sustainability. While operators favored feeders due to cost and time efficiency, barges scored higher due to environmental friendliness and operational flexibility. Notably, 68% of respondents preferred barges for short routes under 100 km due to their role in reducing road congestion and pollution. Furthermore, 73% expected greater barge use over the next five years, driven by technology and environmental policies. Improved waterway infrastructure would lead 82% to use barges more frequently, and 76% believed better intermodal integration would enhance logistics efficiency. This study is limited to the context of Thailand’s domestic maritime logistics and stakeholder perceptions, which may not be fully generalizable to other ASEAN or global port systems. Future research should explore multi-country comparative studies and assess longitudinal trends as green port policies evolve across Southeast Asia.
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    Efficiency improvement of a dual-active-bridge isolated bidirectional DC-DC converter
    (2019-07-01)
    Pruengprach, Nisakorn
    ;
    Suwan-Ngam, Warachart
    The aim of this paper is to present the efficiency improvement of a dual-active-bridge isolated bidirectional DC-DC converter. The converter is designed by considering the type of switching devices and design of a high frequency transformer. The designed 2 kW converter is simulated using PSIM. The prototype is constructed and implemented by using TMS320f28335 DSP. The experimental results show that 96.25% efficiency is achieved at the designed frequency.
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    Harvesting energy from a rotating gear using an AFM-Like MEMS piezoelectric frequency up-converting energy harvester
    (2015-06-01)
    Janphuang, Pattanaphong
    ;
    Lockhart, Robert A.
    ;
    Isarakorn, Don
    ;
    Henein, Simon
    ;
    Briand, Danick
    This paper presents an analytical and experimental study of a compact configuration to harvest energy from a rotating gear using piezoelectric microelectromechanical system harvesters. The reported configuration realizes a contact-Type frequency up-conversion mechanism in order to generate useful electrical energy. The up-conversion mechanism was achieved using an atomic force microscope (AFM)-like piezoelectric cantilever plucked by the teeth of the rotating gear that could be eventually driven by an oscillating mass. This paper describes relevant design guidelines for harvesting energy from the low-frequency mechanical movement of a rotating gear through analytical modeling and finite element method (FEM) simulation followed by experimental validation. Different harvester configurations are investigated to identify the optimal configuration in terms of the output energy and energy conversion efficiency. The latter results are reported for the first time because of the implementation of an original concept based on the coupling of the harvester with a rotational flywheel. The experimental results reveal that free vibrations of the harvester after plucking contribute significantly to the output energy and efficiency. By adding a proof mass, the efficiency of the system can be greatly improved. For plucking speeds between 3 and 19 r/s, average output powers in the order of tens of microwatts were obtained for continuous plucking. By combining interaction energy, friction, and energy absorption, between the harvester and inertial mass, the maximum efficiency of the impact piezoelectric harvesters was found to be 1.4%. The efficiency results obtained were compared with the noncontact magnetic plucking approach further demonstrating the potential of our concept. Finally, different tip-gear materials combinations were evaluated showing the importance of their nature on the reliability of the presented configuration.