https://tcsj.utc.edu.vn/index.php/tcgtvt vi-VN tcsj@utc.edu.vn (Tạp chí Khoa học Giao thông vận tải) hoapt@utc.edu.vn (Pham Thi Thanh Hoa) Fri, 15 May 2026 00:00:00 +0700 OJS 3.1.1.4 http://blogs.law.harvard.edu/tech/rss 60 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/3009 Giáp Trần Văn ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/3009 Fri, 15 May 2026 14:01:02 +0700 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2813 The transportation sector is a key pillar of economic activity, both supporting broader development and remaining highly responsive to shifts in the macroeconomic environment and the pressures associated with deeper international integration. Examining the relationship between debt structure and financial performance in transportation firms is essential in understanding the challenges and guiding financial management in the context of an emerging economy. This study focuses on analyzing the impact of key indicators related to debt structure, including the ratio of short-term debt to total debt (SDR), the ratio of long-term debt to total debt (LDR), and the total debt to total assets ratio (TDR), on financial performance metrics such as earnings per share (EPS), return on equity, and return on assets. The research data was collected from 99 listed transportation firms between 2019 and 2023 and analyzed using fuzzy-set Qualitative Comparative Analysis. The findings indicate that higher levels of SDR are associated with configurations linked to stronger financial performance, suggesting that the use of short-term debt may be conducive to improved performance in the short run. However, the simultaneous presence of LDR and TDR shows varying impacts, indicating that when the ratio of long-term debt or total debt exceeds a reasonable threshold, it can lead to increased financial costs and risks, ultimately degrading financial performance. Therefore, this study offers practical implications for developing appropriate debt management strategies to ensure sustainable growth and financial stability for Vietnamese listed transportation firms. Do Thi Hai Yen ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2813 Fri, 15 May 2026 00:00:00 +0700 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2678 Laminated composite plates are widely used in lightweight structures owing to their high stiffness-to-weight ratio and flexible design capability. However, uncertainties in loads, material properties, and design parameters may significantly affect their mechanical performance and are often not fully addressed in deterministic optimization. This study presents a reliability-based multi-objective optimization framework for the bending design of laminated composite plates under uncertainty. The structural response is evaluated using Isogeometric Analysis combined with the First-order Shear Deformation Theory, allowing geometry and transverse shear deformation to be represented in a unified numerical model. Ply thicknesses are design variables, while maximum transverse deflection and structural mass are minimized as conflicting objectives. The First-order Reliability Method is used to evaluate the reliability index, and the Generalized Differential Evolution 3 algorithm is used to obtain Pareto-optimal solutions. Numerical results show that uncertainties affect the feasible design region and the trade-off between mass, deflection, and reliability. The framework supports reliability-informed design of lightweight composite plate structures. Le Kha Quyen, Khuc Thien Thanh, Nguyen Thoi Trung, Nguyen Trang Thao, Vu Ho Nam ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2678 Fri, 15 May 2026 00:00:00 +0700 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2786 In nature, many swarms of organisms may encounter one another while moving in search of food, which can lead to conflicts between groups. In the field of transportation, there are flows of unmanned vehicles traveling from different directions on the roads; when they reach intersections, the challenge is how these vehicles can pass one another without collisions and then continue toward their destinations as originally planned. Groups of drones fly in the sky, controlled to form various shapes. So how do these drone swarms move past each other without colliding while forming the desired shape? This paper proposes a solution based on the use of Takagi–Sugeno and Mamdani SISO fuzzy structures to compute internal forces within a swarm, target-directed forces, and forces for avoiding other swarms. The proposals above will be validated through MATLAB simulations under different scenarios involving varying numbers of swarms and different numbers of individuals in each swarm. Le Thi Thuy Nga, Nguyen Manh Dung ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2786 Fri, 15 May 2026 00:00:00 +0700 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2799 Early-age temperature development of concrete is governed by the balance between hydration heat generation and heat dissipation to the surrounding environment. Adiabatic calorimetry is commonly regarded as the most accurate experimental method for determining hydration-related thermal parameters of concrete; however, it requires complex equipment and is relatively costly. In contrast, semi-adiabatic calorimetry offers a simpler and more economical alternative. This study experimentally investigates the semi-adiabatic temperature development of concrete mixtures with different fly ash replacement levels. Four mixtures containing 0%, 10%, 20%, and 30% fly ash by mass of cementitious materials were tested using a laboratory calorimeter operated under semi-adiabatic mode. Concrete and chamber air temperatures were continuously monitored, and key thermal indicators were evaluated. The results show that increasing fly ash replacement reduces both the peak temperature and the overall temperature rise under consistent testing conditions. The temperature rise (ΔT) decreased from 23.9 °C to 17.5 °C as fly ash replacement increased from 0% to 30%. The reduction in temperature rise does not follow a strictly linear trend, and no clear monotonic relationship was observed for the time to peak temperature. Semi-adiabatic calorimetry is shown to provide reliable comparative indicators for preliminary assessment of early-age thermal behavior of concrete mixtures. Ngo Duc Chinh, Do Anh Tu, Hoang Thi Tuyet, Do Van Thang, Do Trong Nguyen, Ho Quang Huy ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2799 Fri, 15 May 2026 00:00:00 +0700 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2826 Linear functionals on finite-dimensional polynomial spaces generate fundamental algebraic and analytic structures, including moment sequences, moment matrices, and functional inequalities. Associated with a linear functional on polynomials of bounded degree is a moment matrix whose entries are given by the values of the functional on products of monomials and naturally exhibit a Hankel structure. Adopting an intrinsic functional-analytic viewpoint, this paper studies linear functionals on polynomial spaces without invoking any external representation framework. We develop a unified algebraic setting in which linearity, positivity-type conditions, moment matrices, and a functional inequality are examined simultaneously. We distinguish properties arising purely from linearity from those requiring additional structural assumptions. In particular, we establish a Cauchy-type inequality for linear functionals under mild algebraic conditions, independent of any a priori inner product structure. Under stronger positivity assumptions, the linear functional induces an inner product on polynomial spaces, with the associated moment matrix reflecting this structure precisely. Moreover, the Hankel structure of moment matrices is clarified as an intrinsic consequence of polynomial multiplication. Nguyen Ha Trang ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2826 Fri, 15 May 2026 00:00:00 +0700 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2440 Understanding the dynamic stability behaviour of functionally graded microstructures is of great importance for the development of advanced micro-electromechanical systems, aerospace components, and high-performance smart structures. Accurate prediction of instability regions and vibration characteristics can significantly improve structural reliability, safety, and lightweight design efficiency in modern engineering applications. This study presents an analytical method for analysing the dynamic stability of FG variable thickness microplate based on Mindlin plate theory, modified couple stress theory and the Bolotin method. The microplate thickness is assumed to vary along the length and width with a non-linear variation. The isogeometric analysis method is used to derive the pulse frequency and dynamic stability region of the plate under different boundary conditions. The accuracy of the model and calculation method is verified through numerical comparison with reliable publications. A set of numerical results is collected to evaluate the influence of input parameters; these results are crucial for the optimal calculation and design of variable thickness structures in practice. Nguyen Thao Hoa ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2440 Fri, 15 May 2026 00:00:00 +0700 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2989 Public transport systems in major urban areas of Vietnam have experienced significant growth in recent years, however, the application of information technology in their management and operation remains limited. In cities such as Hanoi and Ho Chi Minh City, fare collection on bus networks is still predominantly conducted manually, with ticket counting and data recording also performed using traditional methods. This approach not only leads to high labor costs but also reduces efficiency in data management and service planning. These limitations hinder the implementation of advanced operational and policy mechanisms, including integrated fare systems, direct passenger-based subsidy schemes, and data-driven service planning that can adapt to fluctuations in travel demand. This study examines the technical, technological, and socio-economic prerequisites for implementing automated fare collection (AFC) systems in Vietnam. Based on this analysis, it proposes a set of solutions aimed at enhancing the operational efficiency and overall performance of urban public transport through the automation and digitalization of fare collection processes. Nguyen Thi Bich Hang ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2989 Fri, 15 May 2026 00:00:00 +0700 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2754 Nowadays, with the development of material science, nano- or microstructures are increasingly of interest in research because of their applications in micro-electromechanical technology, semiconductor chips, or sensors. In this study, the isogeometric approach (IGA) method combining the Mindlin plate hypothesis and the modified couple stress hypothesis is used to analyse the forced vibration of a micro-plate with variable thickness made of materials with variable mechanical characteristics subjected to the effect of different types of dynamic loads. The thickness change of the microplate is considered in two directions with a nonlinear law, while the material characteristics vary with the plate thickness. The model's and method's accuracy are validated by comparing it with results from published studies. Then, the paper surveys the impact of geometric and material coefficient on the transient responses of FG microplate. The research results provide important bases in the design and optimization calculation of micro-electromechanical systems serving the chip and sensor industries. Dam Vu Son Quyen ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2754 Fri, 15 May 2026 00:00:00 +0700 https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2761 Uneven pavement surfaces increase the dynamic loads generated by moving vehicles. However, stability analyses of road embankments often neglect the influence of vehicle vibrations on slope stability. Therefore, considering the interaction between vehicles, pavement conditions, and slope response provides a more realistic evaluation of embankment stability. In this study, vehicle dynamics are simulated using a quarter-car model (QCM), pavement roughness is represented by the International Roughness Index (IRI), and slope stability is evaluated using the Fellenius method. Numerical simulations were conducted for an 8-m-high, 1:1 cut slope in homogeneous saturated cohesive soil under vehicle speeds of 20, 40, and 60 km/h. Four pavement roughness levels with IRI values of 2, 3, 5, and 7 were considered. Dynamic wheel loads for car and truck models were simulated in MATLAB-Simulink over 150 s using the Runge-Kutta integration method. The results show that the static factor of safety (FoS) is 2.05 for the car and 2.03 for the truck. Under dynamic loading with IRI=7, the FoS decreases to 1.96-2.00 for cars and 1.92-1.96 for trucks, depending on vehicle speed. The findings indicate that increasing pavement roughness and vehicle loads reduce slope stability and should be considered in road embankment design and assessment. Huynh Van Quan ##submission.copyrightStatement## https://tcsj.utc.edu.vn/index.php/tcgtvt/article/view/2761 Fri, 15 May 2026 00:00:00 +0700