Dr. Zarko is a Professor at the Maritime Faculty, University of Dubrovnik, CROATIA. Dr. Zarko spent several years as a field engineer and Marine engineer. He is Establishing a cruise management company from the beginning til full certification (Document of Compliance, ISO 9001, establishing technical dep; purchasing dep; HR dep). Managed planned maintenance system of the ships, implemented planned maintenance system -AMOS, organized shore support, purchased certifications from flag state and classification society. Planning and supervising dry docking. Managing vendors and services. Planning, organizing, and supervising refit and rebuilding of ship interiors, new cabins, restaurants, and other public spaces on the cruise ships. Chief Engineer of Cruise Ships. Dr. Zarko has authored over 50 journal articles and conference papers in high-quality engineering and scientific journals such as the NAŠE MORE, Promet-Traffic & Transportation, and Transactions on Maritime Science. Dr. Zarko is a member and a certified engineer of the Croatian Chamber of Engineers of Transport and Transportation Technology - a professional class of marine engineers and traffic engineers on inland waterways, a Junior Editor of the international scientific journal for the sea and seafaring Naše more; and of the Journal of Environmental Science and Engineering Technology. A member of the examination committee at the Ministry of Maritime Affairs of Transport and Infrastructure - Harbour Master's Office in Dubrovnik for taking state professional examinations of a ship's engineer, Chief engineer, and ship's electro-technical officer, He is also actively involved in the international exchange of teaching staff of the Erasmus+ program.

Speech title "Sensors for Current Measurement in Maritime Safety Warning"

Abstract-Maritime safety warning systems rely on sensors that continuously measure the environment around ships and port infrastructure, including wind, waves, water levels, and currents. Among these parameters, currents directly affect vessel maneuvering during berthing. So, accurate current measurements are key for pilots, vessel traffic services, and early-warning systems for maritime management. Several types of sensors are used to measure currents. Mechanical current meters measure flow at a single point using a rotor or propeller. They are simple but prone to fouling and wear. Electromagnetic current meters provide robust point measurements without moving parts. Acoustic Doppler sensors transmit sound pulses and estimate velocity to provide current direction and water level. Doppler velocity logs apply the same principle on ships and underwater vehicles to measure speed relative to the water or the seabed. In addition, radar sensors offer another approach to measuring surface currents over wide areas. Each technology involves trade-offs between spatial coverage, resolution, cost, and robustness. In port environments, acoustic Doppler sensors offer a practical balance between accuracy, depth coverage, and installation flexibility. However, their measurements are affected by missing beam data, acoustic noise, outliers, and device motion. Our research proposes a sensor module consisting of three devices spaced 120° apart in the horizontal plane. Each device measures the component of water velocity along its beam direction. These measurements are then combined to determine the current speed and direction, and the reliability of the resulting estimates under degraded measurement conditions.

Dr.Moon is a tenured professor in the Department of Environmental Engineering at Chosun University in Gwangju, Republic of Korea. He also serves as an associate editor for the Springer journal Environmental Geochemistry and Health. He received both his M.S. and Ph.D. in Environmental Engineering from Stevens Institute of Technology in Hoboken, New Jersey, USA. His research focuses primarily on the remediation of arsenic- and heavy metal-contaminated soils and solid wastes; the characterization of metal-contaminated soils and solid media; the fate and transport of heavy metals in soils; and the remediation of chromite ore processing residue (COPR). Dr. Moon is particularly recognized for his expertise in the stabilization/solidification (S/S) of heavy metal-contaminated soils and solid wastes. With more than 25 years of research experience, he has conducted extensive research on S/S processes for contaminated soils, solid wastes, and dredged materials. He has authored more than 140 peer-reviewed journal articles in the fields of soil remediation and solid waste treatment.

Speech title "Simultaneous Stabilization of Arsenic and Lead in Contaminated Soil Using a Composite Amendment of Fishery By-Product-Derived Partially Calcined Oyster Shell and Biochar"

Abstract-In the Republic of Korea, the enactment of the Act on the Promotion of Recycling of Fishery By-products has established a legislative framework for promoting the recycling of shell waste as a substitute for industrial limestone. However, conventional in situ stabilization/solidification (S/S) using quicklime (CaO) derived from limestone is associated with substantial CO₂emissions during high-temperature calcination and may adversely affect soil health by excessively increasing soil pH. Therefore, the development of low-carbon amendments that support the circular use of fishery by-products while minimizing adverse effects on soil ecosystems is needed. In this study, discarded oyster shells were converted into partially calcined oyster shells (PCOS) and combined with rice husk biochar (RHB) to stabilize soil co-contaminated with arsenic (As) and lead (Pb). This approach was designed to address the potential limitation of pristine biochar, which may promote As mobilization under alkaline conditions. PCOS, calcined at 750 °C for 2 h, and RHB, pyrolyzed at 750 °C for 2 h, were mixed at mass ratios of 1:0.5, 1:1, and 1:2. The resulting amendments were applied to the contaminated soil at rates of 5 and 10 wt%. Following moist curing for 1 week at a moisture content of 35 wt%, the environmental availability of As and Pb was evaluated using 0.1 M HCl extraction. Increasing the PCOS mixing ratio and amendment application rate consistently increased soil pH from 8.37 to 9.34 and improved the stabilization performance. Among the tested treatments, the 10 wt% RHB–PCOS amendment with a mixing ratio of 1:2 exhibited the highest stabilization efficiency, reducing the HCl-extractable concentrations of As and Pb by 37.3% and 43.4%, respectively. These results indicate that PCOS derived from fishery by-products can supply Ca²⁺ and moderate the increase in soil alkalinity, thereby mitigating biochar-associated As mobilization while maintaining effective Pb immobilization. The combined use of PCOS and RHB provides a promising strategy for the valorization of marine waste and the development of low-carbon remediation technologies for As/Pb co-contaminated soils.

Dr. Juan Carlos Astudillo is an Assistant Professor at the Metropolitan University of Hong Kong and a member of the State Key Laboratory of Marine Environmental Health at the City University of Hong Kong (SKLMEH-CityU). He is a marine ecologist specializing in marine biodiversity assessment and ecological engineering for habitat rehabilitation. His research integrates ecological and engineering principles to enhance biodiversity and ecosystem services in degraded coastal environments. These services include biofiltration, carbon storage, nursery habitats, and coastal protection. His work investigates environmental and biological factors influencing biodiversity, including habitat complexity, surface temperature, desiccation, pH, seasonality, competition, and predation. On the engineering side, he develops eco-friendly materials, including a patent-pending eco-concrete made from local waste materials, and designs habitat-enhancing structures that promote species recruitment and survival on artificial shorelines. Dr. Astudillo's research aims to develop innovative and cost-effective ecological restoration technologies that support sustainable coastal development in Hong Kong, the South China Sea region, and beyond. He has an established publication record in marine ecology, biodiversity conservation, and ecological engineering, with numerous studies on benthic communities and invasive species. Currently, he currently serves as Principal Investigator on nine research grants and Co-Investigator on seven additional projects focused on ecological engineering and biodiversity assessment of urban shorelines. He also co-founded afterNATURE, a start-up developing eco-engineering solutions for biodiversity rehabilitation on artificial coastlines. In addition, he is a founding member of the Hong Kong Marine Ecological Association and serves as Thematic Editor for the Hong Kong Register of Marine Species (HKRMS), contributing to ecosystem restoration, environmental education, and marine biodiversity documentation.

Speech title "Eco-Engineered Coastal Infrastructure for Marine Biodiversity Enhancement: Insights from Hong Kong"

Abstract-Rapid coastal urbanization has resulted in widespread shoreline hardening, replacing natural habitats with artificial coastal infrastructure. In Hong Kong, seawalls constructed from concrete and granite are common but typically provide limited structural complexity, reducing the availability of suitable habitats for intertidal marine organisms and contributing to biodiversity loss. To address this issue, a range of eco-engineered panels, tiles, and armour units were developed and tested on existing seawalls over periods of up to two years. These innovations incorporated habitat-enhancing features and environmentally friendly construction materials to increase ecological value while maintaining engineering performance. The results demonstrated that eco-engineered additions can significantly improve intertidal biodiversity by creating diverse microhabitats that help organisms withstand extreme environmental conditions, particularly heat and desiccation stress during the summer. The study also found that sustainable concrete mixtures containing locally sourced waste materials, including incineration ash and dredged marine sediments, are suitable for producing these eco-engineered structures. By combining habitat enhancement with resource recycling, these approaches support both biodiversity conservation and sustainable coastal development. The findings provide valuable guidance for the future planning, design, and implementation of eco-engineered shorelines in Hong Kong and other rapidly urbanizing coastal regions across Asia.

Dr.Li has been committed for an extended period to conducting seismic research on low-reinforcement concrete gravity piers, exploring intelligent compaction techniques for subgrade, and investigating the influence of water content on unsaturated soil. In the field of seismic research, Mr.Li has proposed novel arrangements of longitudinal reinforcement of gravity railway bridge pier, which has been verified by shaking table tests. In the field of intelligent compaction, Mr.Li has proposed 3 fields coupling model to research the influence of water content in the subgrade compaction. Additionally, Mr.Li has been involved in four projects funded by the National Natural Science Foundation of China (NSFC) and published four high-level papers as the sole first author.

Speech title "Intelligent compaction on detecting dam construction defect beneath the surface"

Abstract-The objective of this study was to analyze and percieve the dam compaction defects relying on the intelligent compaction (IC) technology during the construction process. The dynamic response of a vibratory roller was investigated under different depth defects in the dam-subgrade. Four vibratory roller compaction models were created using the finite element method (FEM) to compare their dynamic responses. The results revealed that when the drum-soil interaction was in full contact, the dynamic response could be approximated as a harmonic excitation with a damped system. However, once the interaction was lost, the dynamic response became more complex. Deeper defects exhibited dynamic responses that closely resembled those of an intact dam-subgrade. The time required for the transition from transient to steady state depended on the soil stiffness. The harmonic ratio index Compaction Meter Value (CMV) was found to be closely related to the drum-soil interaction. Additionally, a novel method for assessing acceleration attenuation from the drum to a specified region was proposed and validated. These findings provide valuable references for the application of dectecting defects beneath the surface by IC methods.