Journal of Marine Science and Technology

APPLYING ERROR ASSESSMENT CRITERIA TO IMPROVE THE ACCURACY OF HYDRODYNAMIC CALCULATION MODELS OF HAI PHONG SEA AREA

KIEN DO TRUNG — 2025-08-19

The precision of the hydrodynamic model is crucial for the input data utilized in oil spill models. There are two primary approaches to enhance the model's output: Modifying the coefficients and equations within the calculation framework or refining the initial conditions, which include factors such as topography, temperature, convergence, and meshing. The first approach, while theoretically beneficial, poses significant challenges; despite the availability of open-source simulation software, users must possess extensive scientific expertise and undergo systematic training. Consequently, the second approach is more frequently employed to enhance the accuracy of the hydraulic model. This article presents the criteria for error assessment used to calibrate the initial conditions of the hydrodynamic model developed with MIKE software. Following calibration, an accuracy assessment conducted with data from the Hon Dau station reveals a high degree of similarity, thereby validating the effectiveness of the oil spill simulation program created by the author.

RESEARCH AND DEVELOP OF A COMPUTATIONAL MODEL FOR DETERMINING CROSS TRACK LIMIT XTL SET IN ELECTRONIC NAUTICAL CHARTS

SON LE TUAN — 2025-08-19

According to the International Convention for the Safety of Life at Sea (SOLAS-74), ships must be equipped with Electronic Chart Display and Information System (ECDIS). This equipment is designed to improve the safety of maritime operations and certainly has some undeniable advantages over the use of paper charts. At the same time, the use of ECDIS requires navigators to have a sufficiently high level of expertise to operate professionally. Inadequate setting of safety parameters as well as incorrect interpretation of information from the display can lead to accidents. The study considers the determination of the diagonal (cross track) limit value (cross track) XTL as one of the route safety parameters in ECDIS.

The objective of this work is based on the requirements of the work for the minimum depth of the UKC standard combining information on the size of the ship, the size of the waterway, to build a calculation model that calculates the entire XTL value for input into ECDIS.

APPLYING RANDOM FOREST CLASSIFICATION ALGORITHM TO PREDICT FAUL OF THE MARINE DIESEL ENGINES DUE TO WEAR OF PISTON RINGS

HA TRAN HONG — 2025-08-19

The wear of piston rings in diesel engines is a critical factor affecting engine performance and longevity. This study proposes a method utilizing the Random Forest (RF) algorithm to predict piston ring wear based on engine operating parameters, such as combustion chamber pressure, exhaust gas temperature, fuel injection rate, and torsional vibration. The dataset was collected from engines operating under various conditions and analyzed to identify the relationship between operating parameters and wear. The results demonstrate that the RF model achieves high accuracy, effectively supporting predictive maintenance and optimizing diesel engine performance.

RESEARCH ON THE USE OF VARIABLE FREQUENCY DRIVE (VFD) FOR SEAWATER PUMPS IN COOLING SYSTEM ON BOARD TO REDUCE FUEL CONSUMPTION AND CO2 EMISSIONS FOR VIETNAMESE SHIP FLEET

LAN NGO NGOC — 2025-08-19

Currently, reducing carbon dioxide (CO₂) emissions is a top concern in the maritime transportation sector. To achieve the International Maritime Organization's (IMO) emission reduction target by 2050, numerous solutions have been researched and implemented, these include the use of new fuels, design modifications, efficient ship management and operation, as well as technological solutions for both newbuilds and existing vessels.

In this study, the authors introduce a technological solution: using a variable frequency drive (VFD) to control the seawater pump motor in the ship’s cooling system, aiming to reduce fuel consumption, which directly correlates to lower CO₂ emissions. This technological solution offers high economic efficiency while requiring minimal structural modifications to the system.

STUDY ON THE PERFORMANCE EVALUATION OF SHIP PROPELLER AT DIFFERENT TIMES DURING ITS OPERATION

DIEM LE VAN — 2025-08-19

Maintaining design characteristics of ship propeller plays an important role in ensuring its working efficiency. In practice, technical characteristics of the propeller is downgraded with time, leading to its efficiency reduction. This paper presents the results of a study evaluating the working efficiency of the propeller on the Container ship 566TEU at different times during its operation, including the time of new building and the time after docking for repairs.

STUDY EFFECT OF HULL AND PROPELLER CONDITIONS ON USING ENERGY EFICIENCY

TU TRAN NGOC — 2025-08-19

The paper presents the research results on the effect of hull and propeller conditions at different times of operation, including: New construction, present, after docking to learn the hull and propeller surfaces on using energy efficiency of Fortune Navigator containership. The research results indicate that the condition of the ship's hull and propeller greatly affects the relationship between the power- revolution- speed, which in turn greatly affects the efficiency of energy use on the ship.

STRESS - STRAIN AND MICROSTRUCTURAL EVOLUTION UNDER THE OXY-ACETYLENE TORCH

NHUNG LE THI — 2025-08-19

Ansys software was used to simulate the temperature field on carbon steel plates, stress - strain formation on the entire plate surface. The size of sample was 1000x1000x10mm, the heat source was oxy-acetylene with a heating temperature of about 600⁰C, and moving at a speed of 5mm/s on the plate surface. The simulation results show the positions of tensile and compressive stress on the surface, thereby predicting the deformation trend of the material. In addition, the microstructural evolution and hardness of the material before and after heating were studied. Although there was a change in grain size between different areas, the properties and hardness of the material change slighty compared to the original plate.

RESEARCH ON GRA, PSI AND MOORA METHODS FOR OPTIMAL 3D PRINTER SELECTION

DUONG NGUYEN BINH — 2025-08-19

Bài báo trình bày ứng dụng các phương pháp MCDM để tối ưu lựa chọn máy in 3D dựa trên 8 tiêu chí kỹ thuật và giá cả của 7 mẫu máy in cá nhân. Ba phương pháp được sử dụng gồm GRA (Grey Relational Analysis), PSI (Preference Selection Index) và MOORA (Multi Objective Optimization on the Basis of Ratio Analysis) nhằm so sánh và xác định lựa chọn tối ưu. Kết quả cho thấy cả ba phương pháp đều xác định Ender 3 V3 (P3) là phương án tối ưu nhất, mặc dù có sự khác biệt trong thứ tự xếp hạng các phương án còn lại. Sự khác biệt này chủ yếu do sự khác nhau trong quá trình chuẩn hóa dữ liệu và xác định trọng số của từng phương pháp. MOORA sử dụng chuẩn hóa vector, trong khi PSI và GRA sử dụng chuẩn hóa max - min. Ngoài ra, GRA và MOORA còn xem xét các tiêu chí theo hướng tích cực, tiêu cực và danh nghĩa, trong khi PSI không thực hiện điều này. Nghiên cứu khẳng định tính khả dụng của các phương pháp MCDM trong bài toán lựa chọn tối ưu máy móc.

DESIGN OF CENTRODES OF NON-CIRCULAR PLANETARY GEAR TRAIN THAT MEETS CO-AXIAL CONDITIONS

VIET NGUYEN HOANG — 2025-08-19

The study presents a method for designing the centrodes of planetary non-circular gear. The mathematical model, together with the algorithm for determining the parameters of the gear centrodes, is analyzed and presented through examples to clarify the method's design steps. A numerical calculation program is written in Matlab software to verify the theory's correctness. The results show the correctness of the theoretical basis and algorithm and demonstrate the proposed method's applicability in research and practice.

RESEARCH ON THE INFLUENCE OF FIN SHAPE ON HEAT STORAGE RATE OF CYLINDRICAL THERMAL BATTERIES USING THE NUMERICAL METHOD

NAM TRAN THE — 2025-08-19

This study investigates the optimization of heat transfer in a thermal battery system using phase change material (PCM) to enhance energy storage efficiency. A 2D model with 28,500 elements is developed, utilizing paraffin wax as the PCM and polystyrene (EPS) for insulation. Four fin configurations are analyzed: Case 1 features straight fins; Case 2 incorporates 30° inclined branches; Case 3 includes a top branch; and Case 4 combines two branches at the body and top. Compared to the baseline (Case 1), fin-enhanced designs - particularly Cases 3 and 4 -significantly accelerate PCM melting, reduce thermal equilibrium time, and increase total heat absorption by 16% to 20%. These configurations also achieve a higher average PCM temperature, improving overall heat transfer efficiency. The findings provide valuable insights for advancing thermal storage systems in solar energy and HVAC applications while highlighting opportunities for further optimization through dynamic temperature control strategies.

INFLUENCE OF COLD ROLLING AND QUENCHING TEMPERATURE ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF LOW Mn STEEL

TUAN HOANG ANH — 2025-08-19

This paper presents the results of research on the influence of cold rolling and quenching temperature on microstructure and mechanical properties of low Mn steel. The microstructure of the samples after deformation at different levels: 20%; 50% and 80% shows that the sample after cold rolling at 50% has a grain size of level 10 (8.1µm) ensuring the subsequent heat treatment process. The quenching temperature was investigated at 740^oC; 815^oC and 890^oC; the sample after quenching was tempered at 400 ^oC with a holding time of 11 minutes. Analysis of the microstructure of the steel after heat treatment shows that the structure includes ferrite phases; martensite and residual austenite. After heat treatment, the structure has plate-shaped grains and small spherical grains. The mechanical test results show that after heat treatment, the sample after quenching at 815^oC; The tempering at 400^oC with a holding time of 11 minutes gave a tensile strength value of 1148,8N/mm2 and a maximum elongation of 68.3%. The Rm*A value achieved was 78463,04Mpa*%

STUDYING ABOUT OPTIMIZING HEAT TREATMENT PROCESS OF TiAl6V4 AND Ti-CP WELD JOINTS

XUAN NGUYEN ANH — 2025-08-19

This paper presents the results of research on optimizing the heat treatment process and microstructures of Ti and TiAl6V4 welds after heat treatment. The results of optimization analysis have determined the optimal heat treatment process to ensure optimal results in terms of hardness, strength and relative elongation. The optimal value results at the quenching temperature of 930^oC, the aging temperature of 518^oC and the aging time of 2 hours. With these results, the model predicts the weld hardness is 54,4HRC, the tensile strength is 453,9N/mm² and the relative elongation is 19,3%. The analysis results of the microstructures of the weld after aging at 525^oC for 4 hours have determined the phase decomposition process of the weld after heat treatment. The aging process according to temperature and time decomposes the α' martensite phase after cooling into αm and βr phases, transforms the β phase into α, and changes the shape and distribution of the α and β phases after quenching.

STUDYING ABOUT OPTIMIZATION OF AGING PROCESS FOR HIGH STRENGTH COPPER ALLOY

MAI BUI THI NGOC — 2025-08-19

This work presents the results of optimizing the aging process of Cu-9Ni-3Sn alloy to achieve high strength and ductility. By regression analysis, the experimental results showed that the optimal aging treatment was 354^oC for 2.5 hours, the alloy achieved tensile strength value of 1032.8Mpa and elongation of 8.39% with the difference from the model is less than 10%. By the results of optical microstructure the changing of structure’s this alloy before and after aging are explained; the cause of the increase in strength and ductility of the alloy is analyzed thanks to the mechanism of creating small grains and having defect of crystal structure.

VIBRATION ANALYSIS OF THE OPERATOR WHILE OPERATING A STEEL TWO-WHEEL VIBRATORY ROLLER

CUONG HOANG MANH — 2025-08-19

This paper presents the construction of dynamic modeling and oscillation calculation of steel two-wheel vibratory rollers during operation. Firstly, a vibration model of the vibrating roller was proposed, based on which, a system of differential equations was established. Finding the solution of the above system of differential equations by numerical method gives us graphs describing the oscillation of the roller and the vibration of the operator while operating the vibrating roller.

RESEARCH ON EFFECTS OF WAVES ON STRAIGHT-LINE SWIMMING DYNAMICS OF THE PT-76 TANK

THANH TO VIET — 2025-08-19

The PT-76 tank is an amphibious combat vehicle whose motion dynamics are influenced by environmental conditions both on land and in water. When operating in aquatic environments, surface waves play a critical role in modifying the dynamic characteristics of the vehicle, particularly its drag force, which is a key determinant of swimming efficiency. Understanding the impact of wave-induced disturbances on the vehicle motion is essential for assessing its operational performance and maneuverability. This study systematically examines the influence of surface waves on the dynamic parameters governing the straight-line swimming motion of the PT-76. The findings contribute to a more comprehensive understanding of the vehicle dynamic behavior and serve as a theoretical basis for optimizing its performance in amphibious operations, particularly in overcoming water obstacles.

ANALYSIS OF FACTORS INFLUENCING ON RESISTIVE AND DIGGING FORCES OF EXCAVATORS IN SMALL-SECTION TUNNELS

SANG NGUYEN QUOC — 2025-08-19

To discover the factors influencing on resistive and digging forces of excavators, we develop a mathematical model describing the interaction between excavator bucket and post-blast material in small-section tunnels. We analyze the partially resistive forces and total resistance acting on the excavator bucket in granular environment. Based on this, we select the key parameters to evaluate their influences to excavation resistance. The results show the effectiveness in design and manufacturing of the excavators working in constructional small-section tunnels.

RESEARCH AND TESTING OF POLLUTION FLASHOVER CHARACTERISTICS OF COATED INSULATORS OF HIGH VOLTAGE ELECTRICAL EQUIPMENT ON SHIPS

HUNG NGUYEN VAN — 2025-08-19

Nowadays, high-voltage (HV) electrical systems are increasingly widely used in the maritime field. Ships are now equipped with high-voltage devices to increase capacity and efficiency. However, in harsh working environments, high-voltage electrical safety must meet strict requirements according to regulations. This article presents a method for testing the discharge phenomenon in a working environment similar to that on ships with TERCO equipment. The results show that working environments with different levels of impurities will give different discharge voltage values.

DESIGN OF ADAPTIVE SLIDING FUZZY CONTROLLER BASED ON DISTURBANCE OBSERVER FOR STABLE DEPTH CONTROL OF UNDERWATER AUTONOMOUS VEHICLE

TIEP DO KHAC — 2025-08-19

This paper presents a new method for autonomous underwater vehicle (AUV) navigation control based on the combination of sliding fuzzy control and disturbance observer. The proposed sliding fuzzy controller takes advantage of the strengths of both fuzzy logic control and sliding mode control, enabling stable depth control for the autonomous underwater vehicle. The studied sliding fuzzy control method based on disturbance observer plays the role of estimating the position, velocity and total nonlinear disturbance, thereby resisting the total uncertainty disturbance and increasing the robustness of the control system. The simulation results show that the proposed controller has good anti-disturbance ability, fast response time and high stability. The results demonstrate the ability of the sliding fuzzy controller based on disturbance observer in achieving accurate and robust depth stabilization for the autonomous underwater vehicle, even when subjected to disturbances and environmental changes. This study contributes to improving the control performance of AUV and opens up many further research directions.

DESIGN OF AN ADAPTIVE PID CONTROLLER FOR A CABLE-DRIVEN PARALLEL ROBOT BASED ON NEURAL NETWORKS

BA PHAM DINH — 2025-08-19

The purpose of this research is to improve the controller performance of a cable-driven parallel robot (CDPR) using a nonlinear PID controller. By combining a linear PID controller with a neural network, which has strong learning, adaptation, and nonlinear problem-solving capabilities, a novel adaptive PID controller is developed. Supervised learning of the neural network is used to minimize a cost function. The proposed controller is suitable for cable-driven parallel robots with nonlinearities and uncertainties. Detailed specifications of the control structure, design process, and experimental results are presented. The experimental results show that the proposed control method achieves higher performance for CDPR in joint space.

RESEARCH ON THE DESIGN AND FABRICATION OF LEAN MATERIAL SUPPLY STATIONS FOR PRODUCTIVITY IMPROVEMENT IN INDUSTRIAL MANUFACTURING

TRIEU PHAM VAN — 2025-08-19

In industrial factories, labor productivity and workers' health are becoming significant challenges, particularly at material supply stations. Workers often have to perform manual tasks such as pulling, pushing into, pushing, and carrying, which lead to a high risk of musculoskeletal issues and declining health. Additionally, the current material supply process frequently experiences errors, instability, and requires a large workforce, causing production interruptions and increasing operational costs. To address these issues, this paper focuses on the research, design, and development of a lean material supply station aimed at improving productivity in industrial manufacturing.

DEVELOPING SOLUTIONS TO MONITOR INLAND WATERWAY VESSEL ON COASTAL ROUTES BASING ON RADAR/AIS DATA PROCESSING

VAN NGUYEN THANH — 2025-08-19

Currently, according to regulations, inland waterway vessels are only allowed to operate on coastal routes issued by the Ministry of Transport of Vietnam. However, most of these vessels often operate outside the permitted routes to save time and fuel,... and in order to avoid detection, these vessels often turn off the AIS device (AIS - Automatic Indentification system), move into the blind zone of radar,… The article proposes a solution to monitor inland waterway vessel operating on coastal routes basing on Radar/AIS data to enhance marine safety on Vietnam's coastal shipping route.

EVALUATE BENEFITS OF VESSEL TRAFFIC SERVICE SYSTEM IN HAI PHONG PORT AREA

HUNG PHAN VAN — 2025-08-19

The Vessel traffic service (VTS) system plays an increasingly important role in ensuring traffic safety, improving efficiency and protecting the maritime environment. However, the benefits of VTS have not been fully recognized. In addition, previous assessments often have problems such as: difficulty in collecting data for the parameters of the assessment model; those models do not take into account factors such as reducing the frequency of patrols by channel clearing canoes and saving manpower; it is difficult to distinguish clear benefits when using VTS or not using VTS. In this paper, the benefits of VTS in Hai Phong will be calculated according to the main indicators (safety, traffic efficiency, environmental protection and reducing monitoring costs) applying quantitative methods. When calculating the benefits, the base point is taken as the time before the operation of the Hai Phong VTS system with data from the period 2017-2024. According to the results, the greatest contribution is the environmental protection benefit including the reduction of emissions. Through the cost-benefit analysis, the benefit/cost ratio of VTS is up to 4.832, indicating the great benefits from VTS. This result is evidence for the best reference to evaluate the benefits of VTS system and optimize investment in VTS system for seaport areas.

OVERVIEW RESEARCH ON HUMAN FACTORS IN MARITIME SAFETY

THAI VU DANG — 2025-08-19

Research on maritime accident data has shown that about 80% the causes of maritime accidents are related to human factors, including errors in the work process, subjectivity, lack of knowledge, training and poor management. In addition, human structure, awareness and safety culture in the organization also play an important role. Therefore, a complete assessment of human factors in the maritime field will provide a clear and basic source of knowledge before implementing measures to improve, enhance efficiency and ensure subsequent safety more easily. In this paper, we focus on clarifying issues related to human factors in ensuring maritime safety, explaining terms, assessing the impact of maritime accidents and analyzing published research data to provide an overview of this issue.

RESEARCH ON THE EFFICIENCY OF CARGO TRANSPORTATION AND EMISSIONS OF VESSELS AT MPC HAI PHONG PORT

TAI NGO NHU — 2025-08-19

The Paris Agreement reached at COP26 is carbon neutrality by 2050. In particular, the maritime industry has also made efforts to reduce emissions. The IMO's 2023 strategy for reducing greenhouse gas emissions from ships sets the target: Reduce at least 20% of total annual greenhouse gas emissions from international shipping Reduce at least 70% of total annual greenhouse gas emissions from international shipping, striving to reach 80% by 2040 compared to 2008 and almost zero by 2050. In that context, the requirement for Vietnamese seaports to implement the Prime Minister's commitment to be carbon neutral by 2050. Therefore, research on managing emissions from ships operating at MPC seaports is an urgent requirement. The research results show that the amount of emissions from ships at seaports is very large, 183,948.29 kg in November 2024, the ratio between emissions and cargo circulation efficiency through the port has a very large difference (13.31 times). Therefore, this result is the basis for developing policies and solutions to control emissions of ships operating at seaports, contributing to the implementation of the green port development project in Vietnam.

EFFECTS OF CURING TEMPERATURE ON THE MECHANICAL PROPERTIES OF NATURAL POZZOLAN - CONCRETE

TOAN PHAM VAN — 2025-08-19

The effects of curing temperature on the mechanical properties of concrete using natural pozzolan as cement replacement with the ratio of 20% by mass was investigated. Samples was cured at various temperatures of 10^oC, 20^oC, 30^oC and 50^oC until testing days. It is reported that for normal concrete without pozzolan cured at high temperature 50^oC will have higher early age compressive strength (1, 3 and 7 days) than concrete cured at temperature of 10^oC to 30^oC but the late age of 28 days compressive strength is lower. However, for concrete using pozzolan as a partial replacement for cement, concrete cured at a high temperature of 50^oC has a higher strength than that of other concrete cured at a temperature of 10^oC to 30^oC at ages from 1 to 28 days. It is possible that the pozzolanic reaction rate of natural pozzolan is usually slower than the hydration reaction of cement, so the negative effect of temperature on the strength development of cement was compensated by the strength development of natural pozzolan after 28 days of curing. Although the elastic modulus of concrete has the same trend as the compressive strength, the variation of elastic modulus is not as clear as the compressive strength.

CALCULATION OF CRITICAL FLUTTER WIND SPEED OF LONG-SPAN BRIDGES WITH FLAPS FIXED TO THE HANGERS BY USING REVISED STEP-BY-STEP METHOD

AN TRAN NGOC — 2025-08-19

Long-span bridge decks are very sensitive to the effects of wind. One of the methods to increase the critical wind speed is to install flaps to create additional aerodynamic forces. This paper presents the calculation of the critical flutter wind of a bridge deck section model with flaps fixed to the hanger by using Revised Step-by-Step method. The Logarithmic resistance and flutter frequency are investigated over the entire wind speed range. The calculation results in the paper are the fundamental for further studies on improving the installation of aerodynamic control method.

SAFETY MANNING OF VESSELS IN THE CONTEXT OF DIGITAL TRANSFORMATION AND APPLICATION OF NEW TECHNOLOGY

CUONG NGUYEN MANH — 2025-08-19

The maritime industry is undergoing profound transformation with the rapid integration of digitalization and ship automation. While digitalization promises to bring greater safety, efficiency and sustainability, it also poses new challenges in ensuring safe manning of vessels. This study analyses the impact of increased digitalization on safe manning of ships focusing on seafarer job security, occupational safety and health, and the changing digital operational skills and duties of seafarers. It also examines the role of regulatory bodies and maritime industry stakeholders in revising policies and training models to ensure seafarers are well prepared for the future. The study finds that future commercial ships will be heavily digitalized, especially in the bridge and engine control room, which will significantly change the competencies and responsibilities of seafarers. Therefore, advanced training in digital technology, cybersecurity and seafarer welfare is needed to ensure that seafarers are adequately prepared for the increasing demands of modern ships. Regulators, industry stakeholders and training institutions need to work together to overcome the challenges of digital transformation and maintain a focus on maritime safety.

RESEARCH ON REDUCING PITCHING MOTION FOR FLOATING STRUCTURES USING ECCENTRIC MASSES

GIANG LE THI HUONG — 2025-08-19

Floating structures have been applied in many fields such as housing, ports, wind turbines,... Under the action of wave and wind loads, the floating structure will have pitching motion. This can cause danger to the structure or discomfort to the user. Therefore, it is necessary to study suitable devices to reduce pitching motion of floating structures. This paper introduces the application of eccentric mass device to suppress pitching motion of a rectangular box structure. The equations of motion of the floating structure-eccentric mass system are established. The system is assumed to be subject to harmonic excitation. The effectiveness of the device is demonstrated through numerical simulation results. The Pareto front with different masses of the device has also been investigated.

STUDY ON THE CALCULATION OF THE LOAD-BEARING CAPACITY OF PRESTRESSED REINFORCED CONCRETE SHEET PILES IN RETAINING WALL STRUCTURES USING FRACTURE MECHANICS THEORY

GIANG TRAN LONG — 2025-08-19

The use of fracture mechanics theory in the design of reinforced concrete retaining walls is an advanced method that helps to more accurately assess the load-bearing capacity and durability of the structure, especially when considering the formation and propagation of cracks in the material.

In this paper, the author analyzes the structural components of a revetment constructed from prestressed reinforced concrete piles and introduces a calculation method based on fracture mechanics theory. Through the comparison of calculation results from a specific example, the author evaluates the advantages and limitations of applying fracture mechanics theory and TCVN 5574:2018 in the design of retaining structures using prestressed reinforced concrete piles. The results of crack width calculations according to Eurocode 2-2004 are significantly smaller than those according to TCVN 5574:2018. Based on this, the author proposes applying crack width calculations based on Eurocode 2-2004, which utilizes the Linear Elastic Fracture Mechanics (LEFM) model. This model aligns with the assumptions of elastic behavior in concrete and reinforcement under normal loading conditions, simplifying the calculation process while ensuring the necessary accuracy. It is well-suited for the design of revetment structure using prestressed reinforced concrete sheet piles in Vietnam.

RESEARCH ON PARAMETER OPTIMIZATION FOR PID CONTROLLER TO STABILIZE SHIP TRAJECTOR USING GENETIC ALGORITHM

TIEN NGUYEN VAN — 2025-08-19

Accurate and stable ship heading control is crucial for ensuring maritime safety and operational efficiency. PID controllers have been widely used in ship autopilot systems, however, fine-tuning the PID controller parameters to achieve optimal performance in complex and constantly changing operating conditions is a major challenge. To overcome the above limitations, this paper proposes the use of a Genetic Algorithm (GA) to optimize the parameters of the PID controller, forming a GA-PID controller to improve the quality of the controller. Thereby, this study contributes to improving the performance and reliability of the ship's autopilot system.

FIXED-TIME SLIDING MODE CONTROL OF RUBBER-TIRED GANTRY CRANES

TRIEU PHAM VAN — 2025-08-20

In this paper, a fixed-time robust control algorithm is developed to minimize the tracking trajectory error of the rubber-tired gantry crane system. Firstly, a robust controller is designed based on sliding mode control theory to ensure the output of this system reaches the desired value. Then, the stability analysis of the proposed method based on Lyapunov stability theory, and the calculation of the convergence time are presented, which enables the operator to control the convergence time of the system through the control parameters. Finally, numerical simulation is implemented to verify the effectiveness of the proposed controller in tracking the desired trajectory and having a fixed convergence time.

AN OPTIMIZATION-BASED APPROACH FOR CALCULATION OF FLOATING STRUCTURES’ MOORING LINES

HOAN PHAM QUOC — 2025-08-20

This paper proposes a new method of calculating mooring lines by using the particle swarm optimization algorithm (PSO) to solve the analytical equations describing the mooring line trajectory. The equations of water depth and mooring line length are applied to establish the objective function of the PSO algorithm. The unknowns are the mooring line tilt angle at the bottom and the drift of the floating object are solved automatically by this algorithm. Thereby, the parameters to determine the trajectory and tension of the mooring line are also determined. This calculation method opens up a new approach for calculating this type of structure besides the popular methods today such as the analytical method, the finite element method, etc..

RESEARCH ON APPLYING DEEP LEARNING NETWORKS IN LANE DETECTION FOR SELF-DRIVING VEHICLE SYSTEMS

TIEN LE QUYET — 2025-08-20

Automatic lane detection technology plays a crucial role in enabling self-driving cars to accurately position themselves in multi-lane urban traffic environments. However, recognizing lane markings under different weather conditions remains a significant challenge for traditional image processing methods and computer vision techniques. This study makes a substantial contribution by applying deep learning networks to address the problem of lane detection in autonomous vehicle systems. Specifically, the authors employed an Encoder-Decoder model with a fully convolutional network to effectively detect lanes. The research and experimental processes were conducted rigorously, yielding impressive results with an accuracy of up to 97.82%.

RESEARCH ON GREEN PORT STRATEGY IN THE WORLD AS A USEFUL LESSON FOR THE SUSTAINABLE DEVELOPMENT OF VIETNAM'S SEAPORTS

DUC NGUYEN MINH — 2025-08-14

Vietnam, with its extensive coastline and growing maritime activity, is strategically positioned to benefit from the global shift toward sustainable port development. The implementation of green port strategies worldwide offers valuable lessons as Vietnam charts its own path toward port sustainability. This article examines global green port initiatives and their applicability to Vietnam's context, analyzing current developments, challenges, and opportunities for the future. The findings suggest that Vietnam has made significant progress in adopting green port practices but requires continued investment and policy support to fully realize the environmental and economic benefits of sustainable port development.

THE BLUE ECONOMY: A COMPREHENSIVE ANALYSIS OF ITS NECESSITY AND THE CHALLENGES FACED IN VIETNAM'S GULF OF TONKIN REGION

HA NGUYEN NGOC — 2025-08-14

This research contributes to the development of Vietnam's blue economy by providing an in-depth analysis of the challenges in state management of the maritime sector in the Gulf of Tonkin. The study identifies three main groups of challenges: (1) The legal framework for controlling pollution from ships is incomplete; (2) Inter-regional coordination in port management is limited; (3) The enforcement and monitoring capacity of state agencies needs to be enhanced. The research proposes specific solutions, including the development and improvement of legal documents on the marine environment, the establishment of effective cooperation mechanisms between localities, and increased investment in human resource training and equipment for management agencies. The research findings provide a scientific basis for policy making and the implementation of effective management measures, contributing to the sustainable development of the maritime industry and the blue economy in the Gulf of Tonkin.

ACCESS CONCENTRATION AND COMPETITION IN THE CONTAINER SHIPPING MARKET

HANG NGUYEN THI LE — 2025-08-14

Container shipping is the backbone of the logistics system and the main mode of transportation in global trade. Currently, the container shipping market share tends to be dominated by a few large container shipping companies. In addition, the merge and acquisition of container shipping companies occurring frequently in recent years have caused many changes in this market. Its concentration and competitiveness shape the market structure and have a profound impact on the development of the glabal trade. Understanding the development of large shipping companies, its the concentration and competitiveness helps policy makers formulate appropriate policies. Therefore, the purpose of this study is to measure the concentration and competitiveness of the container shipping market in the period 2018-2024 through the concentration ratio (CR) and Herfindahl-Hirschman Index (HHI). The research results show that 0.1 ≤ HHI ≤ 0.18 and 40%≤CR4≤60%, therefor the container shipping market is average concentration level or monopoly competition.

EXPLORING FACTORS INFLUENCING MULTI-STAKEHOLDERS’ CONTAINER ROUND-USE PLATFORM ADOPTION IN VIETNAM

HONG NGUYEN DUY — 2025-08-15

Voyages of empty containers incur high expenses for the entire supply chain. Several container round-use platforms have been introduced as innovative solutions to better pool these empty boxes. This quantitative study aims to identify factors influencing the adoption of container round-use platforms in Vietnam. Employing the Technology-Organization-Environment (TOE) framework, the research explores contextual factors at the firm level that influence technological innovation adoption. 349 valid responses were collected through an online survey from 1st to 25th July 2023. The data are analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). The findings indicated factors significantly influencing the adoption of container round-use platforms including cost, ease of use, usefulness, relative advantage, firm size, top management support, and workforce. By exploring these factors comprehensively, this research not only validates established adoption drivers but also unveils novel insights into enhancing platform adoption strategies in Vietnam. This study contributes uniquely to the literature by bridging theoretical gaps and offering practical implications for stakeholders seeking to enhance logistical efficiency and sustainability through advanced technological solutions in container logistics.

RESEARCH ON FACTORS INFLUENCING THE CONTAINER SHIPPING THROUGH INLAND WATERWAYS IN NORTHERN VIETNAM

MAI PHAM THI QUYNH — 2025-08-15

Container shipping via inland waterways plays an important role in alleviating pressure on other transport modes, serving as a vital link for maritime transport and promoting sustainable development in the transport industry. Although the North of Vietnam having numerous advantages, such as an extensive network of rivers, which creates significant potential, container shipping via inland waterways has not yet achieved the expected results. Therefore, this study aims to rank the importance of the factors affecting the development of container shipping via inland waterway in the northern region of Vietnam, employing the Fuzzy Analytic Hierarchy Process (FAHP) for assessment. Based on the importance ranking of these factors, critical solutions will be suggested to address this issue.

THE ROLE OF DIGITAL TRANSFORMATION IN ENHANCING OPERATIONAL EFFICIENCY AND MARKET SHARE COMPETITIVENESS OF MAJOR CONTAINER PORTS IN SOUTHEAST ASIA (2019-2023)

GIANG NGUYEN THI HUONG — 2025-08-15

This study analyzes the relationship between digital transformation, operational efficiency, and market share competitiveness of major container ports in Southeast Asia during the period 2019-2023. By utilizing indicators such as growth rate, actual throughput, shift-share analysis, and operational efficiency (DEA), the study clarifies the role of digital transformation in enhancing the competitive capacity of ports. The study emphasizes that digital transformation is not only a key factor in optimizing operational efficiency but also plays a crucial role in maintaining and increasing market share. Specifically, digital transformation helps ports improve productivity, reduce operating costs, and enhance logistics connectivity in the global supply chain. The findings of this study provide important insights for container ports in Southeast Asia to develop sustainable strategies, contributing to strengthening the region's position in international maritime trade.

RESEARCH ON THE INFLUENCE OF THE PORT CITY ECONOMIC FACTORS ON THE THROUGHPUT OF HAI PHONG SEAPORT

GIANG VUONG THU — 2025-08-15

Hai Phong Port is the largest general port in the North, an international gate to Vietnam with a long tradition associated with the development of the city and the region. In recent years, Hai Phong‘s seaport throughput has grown strongly, accounting for 13% of Vietnam's total throughput (Vietnam Maritime Administration). Playing a key role in this achievement must be the role of the city's economic factors that provide resources and great advantages for the growth in Hai Phong’s seaport throughput. This study aims to investigate the impact of Hai Phong’s economic factors on Hai Phong’s seaport throughput using the error correction vector model (VECM). The results indicate that Gross regional Domestic Product (GRDP), Foreign Direct Investment (FDI) and Import-Export Turnover have positive impact on Hai Phong’s seaport throughput. This study’s findings contribute significantly to both the academic and practical aspects of studying the relationship between port cities and seaports.

RESEARCH ON FACTORS AFFECTING THE EFFICIENCY OF THE COLD SUPPLY CHAIN FOR FRESH AGRICULTURAL PRODUCTS IN VIETNAM

HUNG LE MANH — 2025-08-15

The cold chain has the capability to maintain and control humidity, temperature, and other storage conditions for specific types of goods. Its primary objective is to ensure proper storage requirements and extend the shelf life of products before they are distributed to the market. The cold chain provides businesses with additional time for distribution and product delivery to consumers, thereby enhancing customer satisfaction. This study aims to identify the factors influencing the performance of the cold chain for fresh agricultural products in Vietnam. By surveying 117 enterprises, including cooperatives, logistics companies, processing enterprises, and product distributors, and analyzing data using statistical methods such as Cronbach’s Alpha, exploratory factor analysis (EFA), and linear regression, the study identifies three key factors that significantly impact cold chain efficiency: logistics infrastructure, market demand, and government policies and regulations. The findings provide valuable insights to support businesses in developing long-term and appropriate strategies to enhance cold chain efficiency and optimize costs.

RESEARCH ON THE ROLE OF BLOCKCHAIN TECHNOLOGY IN GREEN SHIPPING

TUNG LE SON — 2025-08-15

The shipping industry, with its important role in the global supply chain and being one of the major greenhouse gas emitters, is facing an urgent need to transition to sustainable development. This study investigates the role of Blockchain technology in supporting green shipping, focusing on its ability to enhance transparency, efficient supply chain management, and emission reduction. Through structural equation modeling (SEM), the study results have shown the positive impact of blockchain technology on both the operational efficiency and environmental performance of shipping enterprises. The study has important implications for promoting the development of green shipping, contributing to the goal of sustainable development.

FACTORS OBSTRUCTING THE APPLICATION OF BLOCKCHAIN TECHNOLOGY AT LOGISTICS SERVICE PROVIDING COMPANIES IN HAI PHONG

NAM DINH DUC — 2025-08-15

Blockchain technology has been around for quite some time since the inception of Bitcoin in 2008, but it has only recently been expanded to various other fields, including Logistics. Blockchain is believed to be a breakthrough for the development of the logistics industry [1]. However, in Vietnam, especially in Hai Phong city, the application of this technology is still very limited due to various reasons. The objective of this study is to use methods such as Cronbach’s Alpha reliability analysis, regression analysis, and exploratory factor analysis (EFA) to identify and rank the factors hindering the application of Blockchain. The authors' group identified 6 influencing factor groups, among which the "Environmental Influence" group has the greatest impact. This will help businesses make appropriate strategies and decisions. The research findings provide a reference foundation for logistics enterprises in Hai Phong to formulate strategies aimed at mitigating barriers and enhancing the adoption of Blockchain technology.

APPLICATION OF GREEN BLOCKCHAIN AND ALGORAND ALGORITHM IN AGRICULTURAL PRODUCT TRACEABILITY: THE CASE STUDY OF COFFEE SUPPLY CHAIN IN VIETNAM

ANH VU KIM — 2025-08-15

Truy xuất nguồn gốc ngày càng trở thành một yêu cầu bắt buộc trong hoạt động xuất khẩu nông sản. Tuy nhiên các nỗ lực trong phát triển IoT và các phần mềm truyền thống chưa đáp ứng được yêu cầu ngày càng tăng về tính minh bạch và bền vững của chuỗi. Nghiên cứu này đề xuất ứng dụng công nghệ Green Blockchain để truy xuất nguồn gốc nông sản với trường hợp ứng dụng điển hình trong chuỗi cung ứng cà phê Việt Nam. Bằng việc sử dụng cơ chế đồng thuận PoS cùng thuật toán Algorand, mô hình đề xuất cho phép thu thập dữ liệu theo thời gian thực, đảm bảo tính bất biến của dữ liệu, đồng thời cải thiện tính minh bạch và hiệu quả trong trao đổi thông tin giữa các bên liên quan. Bên cạnh đó, giải pháp này còn góp phần số hóa toàn bộ chuỗi cung ứng nông sản với tác động tối thiểu đến môi trường, là một bước tiến quan trọng trong việc thúc đẩy tính bền vững và khả năng cạnh tranh của nông sản Việt Nam trên thị trường quốc tế.

A STUDY ON INTRA-INDUSTRY TRADE IN THE VIETNAM-CHINA TEXTILE AND GARMENT SECTOR AND STRATEGIC INTERNATIONAL BUSINESS DIRECTIONS FOR ENTERPRISES

MAI PHAM THI PHUONG — 2025-08-15

This study evaluates the current state of intra-industry trade in the textile and apparel sector between Vietnam and China using the gravity model to identify the factors influencing bilateral trade flows. First, the study synthesizes and systematizes the theoretical foundations of intra-industry trade and the gravity model, establishing a basis for analysis. Next, it develops a measurement model for intra-industry trade in textiles and apparel between Vietnam and China. Based on the obtained results, the study assesses the impact of factors such as economic size, per capita income, geographical distance, and agreements on intra-industry trade in this sector. The findings clarify the influence of variables in the model on intra-industry trade between the two countries, providing a foundation for proposing specific solutions to promote textile and apparel trade. These solutions not only aim to enhance the competitiveness of Vietnamese textile and apparel enterprises but also focus on developing appropriate international business strategies to help firms expand their market share and strengthen their position in the Chinese market.

APPLICATION THE FUZZY AHP-TOPSIS METHOD IN SELECTING SOFTWARE PROVIDERS FOR CONTAINER INSPECTION AT DEPOTS, HAIPHONG SEAPORT

NGA PHAM THI HANG — 2025-08-15

With the rapid development of technology and the trend of digital transformation in port operations, warehousing, and depots, container depot operators have shifted towards attracting customers and competing based on the level of technology application in depot operations. Therefore, businesses providing container depot services need to focus on selecting suitable suppliers and operational software to optimize operational efficiency and improve service quality for their enterprises. In this study, the integrated Fuzzy AHP-TOPSIS model is proposed to evaluate and select software providers for container depot operations. Firstly, the Fuzzy AHP hierarchical analysis method is used to build the weight set for evaluation criteria, consisting of eight criteria: service quality, cost, reliability, company reputation in the industry, level of information sharing, system customization flexibility, quality of warranty and maintenance management, and geographical location. Next, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) ranking model is used to evaluate and rank suppliers, selecting the best supplier for the enterprise.

DIGITAL TRANSFORMATION AND SEAPORT LABOUR CHALLENGES IN THE HAIPHONG PORT

DUONG NGUYEN DAI — 2025-08-15

Digital technologies such as Big Data, the Internet of Things (IoT), and Blockchain, when applied in conjunction with the increasing prevalence of digitization and automation, are posing certain challenges to modern ports. The potential stemming from the application of these technologies has been evident in enhancing port operation efficiency, while labor productivity has also been improved through the restructuring of workflows. The subsequent sections of the article will discuss related trends and the development of seaports in the digital era, along with their impact on new skill requirements for workers. This development aligns with the stages of port evolution, namely digitization and automation, as well as the cultivation of new hard and soft skills in port operations, which are said to be shaped by technology-driven trends.

GREEN PORT DEVELOPMENT IN HAI PHONG PORT

YEN NGUYEN THI — 2025-08-15

The paper examines the current situation of green port development in Hai Phong port - what measures are being implemented - how they are benefiting the port and how the port is still lagging behind. The ports included are managed by Hai Phong port Joint Stock Company. The criteria applied are drawn from Vietnam National Green Port Criteria, which will be compulsory in 2030, and international sets of standards from ASEAN, Europe and America. Based on such reviews and practical analysis drawn from the compilation of secondary data, this thesis will identify the possible barriers and challenges, and then provide actionable recommendations suitable for Hai Phong port’s future development plan.