Journal of Military Science and Technology

Mutual information optimization for mitigating catastrophic forgetting in continual learning: An information-theoretic approach

Huu Phuc Ngo — 2025-10-02

Continual learning systems encounter the critical challenge of catastrophic forgetting, where neural networks lose previously acquired knowledge when adapting to new tasks. In this paper, we propose Continual Mutual Information Preservation (CMIP), an information-theoretic approach that leverages Mutual Information (MI) optimization and entropy regularization to retain prior knowledge while learning compact and informative latent representations. CMIP uses an auxiliary network to estimate MI and a replay memory, in which each mini-batch comprises 50% current-task samples and 50% samples replayed from previous tasks. Experiments are conducted on the MNIST-Split and CIFAR-100-Split datasets for the class-incremental learning (Class-IL) setting. On MNIST-Split, CMIP achieves 90.97% accuracy with an 8.81% forgetting rate, outperforming EWC (20.64% accuracy, ~77% forgetting) and GEM (65.1% accuracy, ~33% forgetting). This method is applicable to real-world scenarios, such as robotic perception and real-time data streams.

A secure search method for cloud data storage

Truong Nguyen Dao — 2025-10-02

Storing data on cloud computing platforms offers significant benefits in terms of performance and scalability; however, it also poses serious challenges related to security and privacy. One of the key issues is enabling users to search over encrypted data without revealing its contents to the cloud service provider. In this paper, we propose a secure search method based on searchable encryption combined with a novel digital signature scheme, allowing users to perform keyword queries without decrypting the data. The proposed method is implemented and evaluated in a cloud environment, with results demonstrating acceptable performance and strong security against common attacks such as query analysis.

Analyzing some main components of MDF-500 disinfectant produced in the United States

Toan Vu Ngoc — 2025-10-02

The demand for disinfectants has increased exponentially globally following the COVID-19 pandemic to prevent and control the risk of exposure to harmful microorganisms in humans, the environment, and infrastructure. Contaminated surfaces are places where microorganisms can survive for many days. MDF-500 disinfectant has been recommended by the Environmental Protection Agency (EPA) of the USA. MDF-500 disinfectant has a broad spectrum of antibacterial activity against chemical and biological agents. Although widely used, information on the composition of MDF-500 is minimal. Therefore, it is necessary to conduct analytical research to determine the main components of MDF-500 using qualitative and quantitative techniques, as a basis for improving and upgrading technical features. The main components identified include hydrogen peroxide (H₂O₂), sodium hypochlorite (NaOCl), benzalkonium chloride, cetyltrimethylammonium bromide, and cetylpyridinium chloride. The analysis showed that MDF-500 disinfectant consisted of 1.25% H₂O_2, 9.47% NaOCl, and pH = 10.74.

Development of a natural functional supplement from pleurotus ostreatus and cordyceps militaris to mitigate side effects of chemotherapy and radiotherapy

Phượng Nguyễn — 2025-10-02

Chemotherapy and radiotherapy, while effective against cancer, often induce oxidative stress, immunosuppression, and systemic side effects that impair patient quality of life. This study aimed to develop a natural functional supplement from Pleurotus ostreatus and Cordyceps militaris to mitigate these adverse effects. Optimized extraction was achieved using a 30:70 ethanol–water solvent at 60 °C for 120 min, maximizing phenolic- and protein-associated bioactive recovery. The combined extract demonstrated notable antioxidant activity, with IC₅₀ values of 41.22 ± 2.94 mg/mL (DPPH assay) and 58.73 ± 3.81 mg/mL (lipid peroxidation inhibition), indicating moderate free radical scavenging and membrane lipid protection. Macrophage proliferation assays revealed a biphasic response, with maximal stimulation (12.04 ± 0.21%) at 0.0016 mg/mL, suggesting potent immunomodulatory effects at low doses. These findings support the synergistic potential of P. ostreatus and C. militaris bioactives in reducing oxidative damage and enhancing immune function, offering a safe, sustainable adjunct for patients undergoing cancer therapy.

Investigation of polyphenol derivative extraction from Terminalia catappa leaves and assessment of their corrosion inhibition performance on CB300 steel in saline solution

Dr Tien Ngo Minh — 2025-10-02

This research investigates the extraction of polyphenolic compounds from Terminalia catappa leaves and their application as a natural corrosion inhibitor for CB300 steel in saline solution. The parameters for key extraction, as solvent ratio, temperature, and extraction duration, were tuned to enhance polyphenol yield. The optimal conditions were identified as a 1:1 ethanol-water solvent ratio, extraction at 60 °C, and a heating duration of 30 minutes. The composition of the extract was analyzed using UV-Vis and FTIR spectroscopy, which confirmed the presence of polyphenolic functional groups. The effectiveness of preventing corrosion was measured using SEM, EDX, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The results indicated that the extract created a protective layer on the steel surface, diminishing corrosion activity. The corrosion rate was decreased by 42.39% relative to the control at an optimum concentration of 0.004% in a 3.5% NaCl solution. Nevertheless, elevated extract concentrations marginally reduced inhibitory efficacy owing to heightened acidity. This study illustrates the efficacy of the extract from Terminalia catappa leaves as a sustainable and environmentally friendly corrosion inhibitor for steel structures in marine settings.

Study on the effects of temperature, deposition cycle number, and cobalt additives on the properties of the positive active material in nickel-cadmium batteries

The Nam Dao — 2025-10-02

This study investigates the effects of deposition temperature, number of deposition cycles, and cobalt (Co) additives on the structural and electrochemical properties of the positive active material in nickel–cadmium (Ni–Cd) batteries. The purpose is to optimize fabrication parameters to enhance material utilization efficiency and battery performance. Electrodes were fabricated by impregnating porous nickel substrates with nickel nitrate solution, followed by chemical conversion in potassium hydroxide under varying temperatures (65 – 80 °C) and repeated for different cycle numbers (1 – 5). A cobalt nitrate post-treatment was applied to selected samples. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and hydrostatic weighing methods were employed to characterize microstructure, composition, density, and porosity. Charge–discharge performance was evaluated using prototype Ni–Cd cells. Results show that the optimal deposition temperature range is 70 – 75 °C, which promotes uniform active material distribution and high density while maintaining sufficient porosity. Four deposition cycles yielded the best balance between mass loading and structural stability. The addition of cobalt improved utilization efficiency by approximately 5.2% and reduced internal resistance from 7.15 mΩ to 4.85 mΩ. These findings provide a scientific basis for improving Ni–Cd electrode fabrication, and future studies may explore long-term cycling behavior and alternative conductive additives.

Study on the removal capability of trinitrotoluene in water using the UV/WO₃/H₂O₂ photo oxidation method

Trong Nghia Dinh — 2025-10-02

The paper presents the results of synthesizing WO₃ by the chemical precipitation method, along with an evaluation of its physicochemical properties, morphology, crystal structure, and chemical characteristics. In addition, preliminary results are introduced regarding the removal efficiency of TNT from aqueous solution by photocatalytic oxidation, in which •OH and h⁺play the main role as oxidizing species. The results indicate that the synthesized WO₃ possesses a hexagonal crystal structure, a density of 7.920 g/cm³, an absorption intensity of 1.45 a.u at a wavelength of λ = 285 nm, and a band gap energy of approximately 3.3 eV. The protonation process favors the widening of the energy band gap and enhances the oxidation potential of WO₃, thereby improving its photocatalytic performance and increasing its ability to absorb UVB light. The UV/WO₃/H₂O₂ photocatalytic oxidation process, with a fixed H₂O₂ concentration of 2.94 × 10⁻³ M, an optimal catalyst dosage of 300 mg WO₃, and a UV lamp power of 10 W, achieved a TNT removal efficiency of 98.7% at an initial concentration of 100 mg/L after 60 minutes of reaction under ambient temperature.

Research and development of strategic technologies for military and defense missions: A review

Nguyen Trang Minh — 2025-10-02

This paper provides a comprehensive view of the impact of strategic technologies on modern warfare. The paper asserts that this is not a series of individual advances but a composite revolution shaped by the convergence of many important technologies such as artificial intelligence, robotics and automation, hypersonic weapons, quantum technology, space technology and cyber technology, and biotechnology, which have profound impacts on military operations. The analysis synthesizes assessments from defense organizations, academic research, and government to highlight the significant changes in operations and the erosion of traditional deterrence models. The paper concludes by proposing policy solutions for Vietnam’s defense modernization to effectively respond to the challenges and take advantage of the important opportunities brought by these global trends.

Study on the determination of pharmaceutical products containing amoxicillin and clavulanic acid by HPLC/DAD method

Dr Thuan Mai Huu — 2025-10-02

Amoxicillin, a β-lactam antibiotic, is commonly combined with clavulanic acid to extend its antibacterial spectrum. Dissolution testing of pharmaceutical formulations containing these two substances has seldom been reported, largely due to the chemical instability of clavulanic acid and the analytical challenges of simultaneously quantifying both components. This lack of standardized methodology represents a significant research gap in the quality control of Amoxicillin/Clavulanate products. The objective of this study was to develop and validate a robust HPLC/DAD method for dissolution testing of the commercial formulation Vigentin. Dissolution was performed in ultrapure RO water (resistivity 18.2 MΩ·cm at 25 °C) under tightly controlled temperature and stirring speed. Chromatographic analysis employed a C18 column, a sodium dihydrogen phosphate/methanol (95:5, v/v) mobile phase, and UV detection at 220 nm. The validated procedure met all requirements for specificity, repeatability, and system suitability, with excellent linearity (R² > 0.9998). Dissolution quantification of six samples showed amoxicillin release between 93.9% and 98.9%, and potassium clavulanate between 103% and 107%, all above the minimum acceptance criterion of 75%. These results demonstrate that the proposed method effectively fills the methodological gap and provides a feasible, reliable tool for routine pharmaceutical quality evaluation of this clinically important drug combination.

Designing a high-performance eyepiece for a 0.97-inch OLED microdisplay

Bảo Trần Tiến — 2025-10-02

The eyepiece is an essential component in optical equipment such as binoculars and optical sights; however, its design has received less research attention compared to objective lenses. In thermal imaging sights, images are displayed on a microdisplay and viewed through the eyepiece. OLED microdisplays, known for their high image quality, durability, reasonable cost, and common diagonal sizes (0.5, 0.6, and 0.97 inches), are increasingly adopted in both research and commercial optical systems. This paper presents a design methodology for an eyepiece tailored to a 0.97-inch microdisplay used in thermal imaging sights. Optical evaluation based on MTF, chromatic aberration, field curvature, and distortion demonstrates that the eyepiece meets the necessary requirements for viewing large-size microdisplays. The design is suitable for fabrication and integration into thermal sighting systems.

A method for designing pixelated camouflage patterns for forest terrain backgrounds

Thành Lâm Nguyễn — 2025-10-02

Camouflage is a critical component of modern military operations, enabling objects to blend visually into their surroundings. Traditional disruptive patterns used widely from the 1970s to early 2000s are increasingly replaced by pixelated camouflage. This study proposes a design method for pixelated camouflage patterns tailored to forest terrain. Effectiveness is evaluated using Peak Signal-to-Noise Ratio (PSNR) and Histogram Intersection (HI), which assess visual and color similarity. Results show the designed patterns resemble forest backgrounds in color and texture, indicating practical potential.

Enhancing the kinematic quality of a single-axis stabilizing platform on a high-speed spinning-body aircraft

Dr Tuong Hoang Manh — 2025-10-02

Within the orientation system, a single-axis stabilizing platform is employed to mitigate the effects of high-speed aircraft body rotation on the sensors. To analyze its kinematic characteristics, this paper develops a dynamic model of the stabilizing platform's motion. Misalignment between the platform's axis and the rotational axis of the spinning-body aircraft introduces disturbance components that affect stabilization quality. This paper proposes a solution to reduce platform oscillations by employing a viscous vibration absorber. Simulation results using MATLAB Simulink clearly demonstrate the effectiveness of this approach.

A robust adaptive controller for underactuated ASVs in loose path-following with an added error and a new control handpoint

Duc Sang Cao — 2025-10-02

Controlling an ASV to follow a desired trajectory poses a significant challenge due to the unstable structure of its operating environment, which is often affected by disturbances such as wind, ocean waves, and currents. Furthermore, the ASV's dynamic model is typically highly nonlinear and contains many uncertainties. In this work, we develop an adaptive controller for an underactuated ASV to address the path-following problem under uncertain disturbances. To deal with the underactuation, a small error is added to the tracking error, and a new control hand-point technique is applied. The guidance and force adaptive control laws are designed, and their stability is proven using Lyapunov theory. In addition to the theory, Simulations in the MATLAB-Simulink environment are conducted and compared with other methods. Simulation results demonstrate the robustness of the proposed controller under unknown disturbances.

A study on control command synthesis algorithm for single-channel flying equipment with linear steering vane

May Phạm Văn — 2025-10-02

This paper presents the algorithm and mathematical foundation for control command synthesis applied to single-channel flying equipment equipped with a linear steering vane. The proposed algorithm is developed based on optimal control principles, with a cost function aiming to minimize control energy. From the resulting control law, a relationship is established between the control signal and the normal force acting on the flying equipment. Simulation results are conducted to demonstrate the superiority of the proposed control law over relay-based control, particularly in applications involving single-channel flying equipment.

Dual-Stage Quaternion Estimator: An advanced method for orientation and angular kinematics estimation based on IMU sensor fusion

Thuấn Trương — 2025-10-02

In modern orientation and control applications such as robots, unmanned vehicles, or pan-tilt stabilization systems, accurately estimating orientation angles, angular velocities, and angular accelerations from inertial measurement unit (IMU) data is a significant challenge due to noise, gyroscope bias, and system nonlinearity. Solutions involving Extended Kalman Filter (EKF) have shown many advantages in significantly improving "filtering" quality; however, most only focus on orientation angles and angular velocities, neglecting angular acceleration—a crucial quantity in complex motion conditions. This paper proposes an improved filter, the "Dual-Stage Quaternion Estimator" (DSQE), which uses a two-stage structure with stage 1 applying an Unscented Kalman Filter (UKF) based on quaternions and stage 2 using a linear Kalman filter to estimate angular dynamics, including angular jerk. This method improves the accuracy of orientation estimation thanks to the second-order Taylor expansion and the UKF's ability to handle nonlinearity, while also providing accurate orientation angles in complex motion conditions. Simulation results show that DSQE with UKF outperforms traditional methods, especially in scenarios with strong vibrations or high accelerations.

Multi-domain feature-based early detection of bearing faults using MLP classifier on NASA IMS dataset

Nam Phạm Văn — 2025-10-02

The degradation of bearing components in industrial machinery leads to increased maintenance costs and unexpected operational downtime. This paper presents a novel methodology that integrates multi-domain statistical feature extraction spanning both time-domain and frequency-domain characteristics to enhance the precision of bearing fault detection. A Multi-Layer Perceptron (MLP) model was trained on the NASA IMS Bearing dataset, achieving a classification accuracy of 86.5% across five degradation stages. Experimental results demonstrate that the proposed method outperforms traditional classifiers such as Support Vector Machine (SVM) and Random Forest, particularly in data-scarce environments. Furthermore, the model is well-suited for deployment on resource-constrained embedded diagnostic systems. This approach offers a practical and efficient solution for predictive maintenance, contributing to the reduction of operational costs in industrial applications.

Reconstructing degraded SPECT myocardial images via deep biophysical models: A modern computational approach

Dr Trung Nguyen Thanh — 2025-10-02

Myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) is a critical tool for diagnosing coronary artery disease, but it is often affected by signal degradation due to soft tissue attenuation. In this study, we utilize a publicly available SPECT MPI dataset to establish a benchmark for the task of attenuation correction (AC) by reconstructing AC images from non-attenuation corrected (NC) inputs in a 2D slice-to-slice manner. We implement and compare the performance of several advanced generative models, including generative adversarial networks (GANs) and diffusion models. These models are trained on both general-domain and medical-domain data to evaluate their reconstruction capabilities. The results show that modern deep learning approaches can effectively generate high-quality AC images, demonstrating promising potential for integration into computer-aided diagnosis (CAD) systems for SPECT MPI.

Identification of process parameters in CDA-110 copper T-shaped tube hydroforming

Do Trong Dai — 2025-10-02

This study develops a systematic method to identify the optimal process parameters of a T-shaped tube hydroforming process. Three process parameters: (1) axial displacement, (2) pressure amplification, and (3) maximum inner pressure are examined to optimize two critical performance metrics: minimum wall thickness (STH) and branch height (Height). Finite element analyses were conducted in Abaqus/Explicit to characterize the input-output relationships. Multi-objective optimization based on the Pareto front approach is applied to identify optimal process parameters that trade-off between STH and Height. Numerical validation demonstrates the effectiveness of the presented method.

Establishing the sensitivity diagram of the inertia impact mechanism in the V-25 fuze

Dr Son Bui Xuan — 2025-10-02

The paper presents the construction of a sensitivity diagram for the inertia impact mechanism with two mass-dispersing side cushions, based on the construction of a mathematical model that describes the mechanism's operation upon target impact. The reliability of the inertia impact mechanism under various impact angles is determined using analytical methods, with input parameters of the inertia impact mechanism in the V-25 fuze. The research results enable an evaluation of the operational capability of the V-25 fuze's inertia impact mechanism and can serve as a basis for researching and designing the inertia impact mechanisms with of two mass-dispersing side cushions in the fuze.

Regarding the calculation method for a spring-driven gyroscope in rotating aircraft

Duy Nguyễn Đình — 2025-10-02

The study presents a method for calculating spring-driven gyros used in a coordinator for rotating aircraft. By analyzing the relationship between the dimensions of the spiral spring and the gyro rotor, as well as the characteristics of the spiral spring, the authors develop a mathematical model to describe the motion of the spring-driven gyro during its spin-up and operational phases. Additionally, a method for determining the key kinematic parameters of this gyroscope type is proposed. The simulation results showed that the spring-driven gyroscope has a short start-up time of 0.017 s, a maximum rotational speed of 21,000 rpm, a drift around the outer frame axis not exceeding 5° within 20 s, and a frame-folding time of 60 s. These characteristics meet the requirements for gyroscopes used in rotating aircraft with short operating duration.