Journal of Military Science and Technology

Optimization of the encryption and signal processing algorithm of the functional testing device in communication with control modules of the aerial vehicle ground launch system

2025-12-29T03:41:25+00:00

This paper proposes a solution to enhance the reliability and security of the data transmission channel between the Functional Testing Device and control modules of the aerial vehicle ground launch system under harsh operating conditions, where both intentional and random electromagnetic interference may occur. Based on the principles of game theory, the study models the problem of optimizing encryption parameters and feedback mechanisms as an adversarial interaction between the communication system and the interference source. The objective is to maximize the guaranteed data transmission rate under an average interference power constraint. An optimization algorithm is proposed to select the most suitable set of parameters (code block length, error correction capability, and signal basis) adapted to the specific characteristics of command and status data in the missile system. Simulation results demonstrate that the proposed solution significantly improves anti-jamming capability compared to conventional methods, thereby enhancing readiness and safety in the missile launch preparation and firing process.

Safe reinforcement learning versus classical controllers for voltage regulation and power quality in the IEEE 33-bus distribution system

2025-11-18T06:32:20+00:00

Modern distribution networks face increasing challenges due to the integration of inverter-based resources and stochastic load variations. This study aims to evaluate whether advanced controllers, including a reinforcement learning based safe controller, can provide superior voltage regulation, stability, and power quality compared with conventional proportional–integral, droop, and predictive optimal strategies. The IEEE 33-bus feeder was simulated using realistic 24-hour demand data and sensitivity matrices derived from feeder impedances. Four controllers were implemented under the linearized DistFlow formulation with explicit constraints on voltage deviation and reactive power limits. The analysis focused on both control quality indices, such as settling time, overshoot, steady-state error, and integral squared error, and power system indices, including voltage deviation, regulation, total harmonic distortion, power factor, and network losses. Results show that the safe reinforcement learning controller achieved the fastest settling time of 16.8 hours, the lowest overshoot of 3.2 percent, and the smallest steady-state error of 0.0065 per unit, while also reducing power losses to 0.145 megawatts and maintaining voltage stability above 0.95 per unit. By contrast, the proportional–integral controller exhibited overshoot of 12 percent, harmonic distortion of 8.18 percent, and voltage drops below 0.90 per unit. These findings indicate that embedding safety guarantees into reinforcement learning yields controllers that not only surpass classical strategies but also meet utility-relevant criteria, providing a promising pathway for future deployment in smart distribution networks.

Adaptive neural network controller for trajectory tracking of wheel mobile robots with velocity constraints

2025-11-19T07:43:34+00:00

This paper presents an adaptive neural control scheme for trajectory tracking of a nonholonomic wheeled mobile robot (WMR) under velocity constraints. The control objective is to ensure stable motion tracking despite model uncertainties and external disturbances. An adaptive neural network (ANN) is employed to approximate unknown nonlinearities in the robot dynamics, while an auxiliary control law compensates for velocity limitations and ensures safe operation within the admissible region. The proposed design combines model-based feedback with data-driven adaptation to improve tracking accuracy and robustness. The stability of the overall closed-loop system is demonstrated through Lyapunov analysis, guaranteeing the convergence of the tracking errors. Simulation results validate that the proposed ANN-based controller achieves faster convergence, smaller steady-state errors, and stronger robustness compared to conventional model-based controllers.

Improving the quality of deep-tissue elastography imaging: A Kelvin–Voigt model-based and multi-point denoising approach

2026-02-09T01:19:13+00:00

Tissue stiffness has been recognized as an important indicator of pathological conditions. Ultrasound elastography, which relies on the mechanical stiffness properties of tissue, has proven effective in diagnosing various Malignant conditions like breast cancer, thyroid disorders, prostate abnormalities. With advantages including speed, low cost, non-invasiveness, and reliability, elastography has gained significant attention and is now widely applied in clinical diagnostics. However, this technique faces challenges in deep tissue regions, where increased noise and shear wave attenuation lead to degraded image quality and reduced diagnostic accuracy. To address these limitations, this study proposes an integrated approach combining LMS filtering, median filtering, and enhanced multi-source excitation to improve the signal-to-noise ratio (SNR) and enhance image quality in deep tissues. The effectiveness of the proposed method is evaluated using RMSE and Q-index metrics, demonstrating significant noise reduction and improved diagnostic reliability.

Segmentation and reconstruction of wireless signals under interference using the FoT-UNet neural network

2026-01-06T10:45:02+00:00

The increasing prevalence of intentional radio frequency (RF) jamming poses significant challenges to spectrum monitoring and signal reconstruction in complex interference environments. Accordingly, this paper proposes FoT-UNet, a two-stage deep learning framework for time–frequency spectrum segmentation and reconstruction of jammed wireless signals. In the first stage, FoT-UNet-Seg performs RF interference segmentation on 256×256×1 short-time Fourier transform spectrograms, employing the Focal-Tversky loss to enhance sensitivity to small jamming regions. In the second stage, FoT-UNet-Recon, leverages the cleaned spectral features to reconstruct the original spectrum, optimized using a mean absolute error (MAE) objective to minimize amplitude distortion. Experiments on a dataset of 30,000 samples demonstrate that FoT-UNet-Seg achieves IoU = 0.9933, F1 = 0.9966, and Precision = 0.9971, with an average processing time of 13.9 ms per image and 10.9 million parameters. The reconstruction network attains MAE = 0.0801, MSE = 0.0125, PSNR = 20.04 dB, and SSIM = 0.7357, indicating accurate recovery of spectral patterns even under broadband burst interference. In comparison, our approach outperforms several other works in the same task.

Research and design of a waveguide sum-difference comparator for monopulse radar applications

2026-03-13T07:04:53+00:00

This paper presents the research and design results of a waveguide sum-difference comparator for monopulse radar applications. The proposed sum-difference comparator is designed to meet the requirements of wide bandwidth, low insertion loss, and high port isolation, while maintaining good amplitude and phase balance across the operating frequency band. Ku-band monopulse radar systems demand waveguide combining networks with high stability and low loss to ensure accurate generation of sum and difference signals. Conventional waveguide T-junction–based comparators are typically limited in bandwidth and exhibit insufficient port isolation, which can degrade monopulse tracking performance. In this work, a Ku-band 4×4 waveguide power combining and dividing network based on a hybrid configuration of H-plane and E-plane slot couplers is proposed for monopulse radar applications. The H-plane slot couplers are employed to achieve in-phase power combining, while the E-plane slot couplers provide phase inversion and enhanced port isolation. Full-wave electromagnetic simulations are carried out using the CST Studio Suite to optimize the geometrical parameters and ensure compliance with the design specifications. The proposed design offers a compact, robust, and high-power-handling solution suitable for Ku-band monopulse radar front-end processing systems.

A sensitivity approach for calculating power losses and bus voltages in radial distribution grids

2026-03-24T08:47:17+00:00

This paper presents a sensitivity-based method for the calculation of power losses and nodal voltages in power distribution systems. Sensitivity factors of power losses and voltage magnitudes with respect to nodal power injections based on the exploitation of the radial structure of distribution grids are rigorously represented. The power losses and voltages attained from this sensitivity approach are validated using a six-bus distribution system and compared with the Alternating Current Power Flow (ACPF) method that solves non-linear power flow equations iteratively and provides accurate solutions. The calculated findings show that sensitivity method errors are minor and highly acceptable in comparison with the ACPF method when power injections vary slightly. For voltages, the computed results from both techniques are nearly the same.

Development of nanocurcumin-incorporated biopolymer films for enhanced stability and pH-responsive monitoring

2026-01-23T10:36:00+00:00

This study developed biopolymer films using chitosan (CS), carboxymethyl cellulose (CMC), and pectin (Pec) incorporated with nanocurcumin (NCur). FE-SEM and ATR–FTIR analyses confirmed that NCur integration created denser microstructures through strengthened molecular interactions, improving tensile strength and elongation by up to 17% and 20%, respectively. Furthermore, NCur reduced moisture content and doubled antioxidant radical-scavenging activity. The films exhibited distinct pH-dependent colour transitions from yellow (acidic) to reddish-brown (alkaline). In beef storage trials, the films successfully monitored spoilage via recognisable colour shifts over two days. Overall, these NCur-loaded films demonstrate strong potential as sustainable, intelligent packaging for active preservation and real-time freshness monitoring.

Optimization of formulation components and evaluation of 2-chloroethyl ethyl sulfide (CEES) removal efficiency of a PVA/Fuller’s Earth/surfactant-based skin decontamination gel

2026-02-27T02:52:49+00:00

Vesicants are chemical warfare agents that pose severe risks to human health upon exposure, particularly in military contexts. This study presents an optimized hydrogel comprising Polyvinyl alcohol (PVA), Fuller’s earth, and decyl glucoside for the rapid ex vivo decontamination of 2-chloroethyl ethyl sulfide (CEES), a sulfur mustard simulant, from porcine skin. The formulation synergizes the polymeric matrix of PVA, the adsorption capacity of Fuller’s earth, and the micellar solubilization of decyl glucoside. Residual CEES was quantified via GC-MS. Using a Box-Behnken design and Response Surface Methodology (RSM), the impact of component ratios on dynamic viscosity and decontamination efficiency (DE) was analyzed. Results revealed that DE is driven by the significant quadratic effects of individual components, rather than linear viscosity trends or pairwise interactions. The optimal formulation (9.0 wt% PVA, 11.7 wt% Fuller’s earth, and 2.1 wt% decyl glucoside) achieved a maximum DE of 96.5%. These findings confirm the proposed gel as a highly effective, rapid-response countermeasure for vesicant exposure, validating the role of RSM in formulation design.

Photocatalytic degradation of rhodamine B using Cu₂O prepared via Terminalia catappa leaf-extract route

2026-01-19T07:31:21+00:00

A green and sustainable method for synthesizing a cuprous oxide (Cu₂O) photocatalyst was established using the extract from Terminalia catappa leaves as a natural reducing and stabilizing agent. The resulting Cu₂O displayed a well-defined cubic morphology, high crystallinity, and phase purity, as confirmed by SEM, XRD, FTIR, and EDX analyses. UV-Vis diffuse reflectance spectroscopy indicated strong visible-light absorption, with characteristic bands at 449 and 475 nm and a narrow band gap of 2.12 eV, supporting its suitability for visible-light-driven photocatalysis. Photocatalytic activity was assessed via degradation of Rhodamine B (RhB) under visible-light irradiation, achieving over 90% degradation within 120 minutes. Kinetic analysis showed that the photodegradation data were best fitted by a pseudo-second-order model, reflecting an apparent kinetic behavior in which surface reactions and adsorption-related processes involving photogenerated charge carriers play a dominant role. Reusability tests demonstrated satisfactory stability, with the catalyst maintaining more than 80% degradation efficiency after five cycles. These findings demonstrate the potential of Terminalia catappa leaf-extract-mediated Cu₂O as an eco-friendly, low-cost, and efficient photocatalyst for wastewater treatment.

The influence of graphene oxide functionalized with 3-aminopropyl triethoxysilane on the corrosion protection performance of epoxy coatings

2026-01-27T06:50:59+00:00

This study reports the synthesis and characterization of graphene oxide functionalized with 3-aminopropyl triethoxysilane (GO-APTES) to enhance its dispersion within an epoxy resin for advanced anticorrosion coating applications. The structural morphology of the material was characterized using Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDX). The anticorrosive performance of the GO-APTES/epoxy nanocomposite coating was evaluated using electrochemical impedance spectroscopy (EIS). The epoxy coating incorporating GO-APTES exhibited outstanding corrosion resistance, effectively protecting the metal substrate for up to 60 days of immersion in a 3.5% NaCl solution. The results indicate that the silane-functionalized graphene oxide not only achieves excellent dispersion within the epoxy matrix but also contributes to forming a compact and uniform barrier layer that significantly inhibits the diffusion of corrosive media into the substrate. In particular, the GO-APTES/EP coating demonstrated a high corrosion protection efficiency of 95.61% on CT3 steel, further confirming the remarkable barrier performance of the modified system.

Investigative synthesis and optimization of Ca²⁺/Al³⁺ dual cross-linked alginate hydrogel beads for water vapor adsorption

2026-03-19T01:09:14+00:00

Spherical alginate hydrogel beads simultaneously cross-linked by calcium and aluminium ions were fabricated via extrusion-gelation to investigate their potential for atmospheric water harvesting. Alginate concentration (1–5 wt%) and calcium/aluminium molar ratios (1:1, 1:3, 3:1) were systematically optimized. Scanning electron microscopy demonstrated that 2% alginate with a 1:1 cation ratio yielded the most uniform and porous surface morphology, while elevated aluminium content promoted undesirable surface crystallization. The highest specific surface area was confirmed (15.349 m²/g) for the 1:1 formulation with broad mesopore distribution. Fourier-transform infrared spectroscopy validated calcium-oxygen and aluminium-oxygen cross-links alongside characteristic alginate functional groups, and energy-dispersive X-ray mapping confirmed homogeneous elemental distribution via the egg-box mechanism. Thermogravimetric analysis revealed dehydration at 173.8 °C, alginate pyrolysis total 49.65% mass loss to 700 °C, and approximately 50% thermally stable residue. Water vapor adsorption reached 4.22 g/g at 90% relative humidity and 3.84 g/g at 70%, with over 80% uptake achieved within 15–20 hours. Thermal regeneration retained 92-97% capacity over three cycles, establishing these hydrogels as promising low-cost sorbents for atmospheric water harvesting.

Synthesis of reduced graphene oxide by electrochemical method for electromagnetic interference shielding applications

2026-02-04T03:18:36+00:00

In this study, graphene oxide (GO) was synthesized via an electrochemical exfoliation method in an (NH₄)₂SO₄ electrolyte solution using two different types of graphite electrodes, namely graphite foil and graphite plate, under an applied potential of 10 V with a controlled current density for 45 minutes. The obtained GO was subsequently subjected to thermal reduction in a nitrogen (N₂) atmosphere at 800 °C for 1 hour with a heating rate of 5 °C/min, yielding reduced graphene oxide (rGO). The structural and morphological characteristics of rGO were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDX). The results revealed that rGO synthesized from graphite foil electrodes exhibited a multilayered structure with a thickness corresponding to 8–15 graphene layers. This morphology is considered highly suitable for the development of materials for electromagnetic interference (EMI) shielding applications.

A weighted linear combination-based multi-criteria framework for prioritizing environmental monitoring sites in coastal military areas of the Mekong Delta, Vietnam

2026-03-10T08:41:03+00:00

Coastal military areas in the Mekong Delta are increasingly exposed to environmental pressures from salinity intrusion, climate change, and combined military-civilian pollution sources. However, most environmental monitoring frameworks are designed for civilian contexts and rarely consider the operational characteristics of military facilities. This study proposes a Weighted Linear Combination (WLC)-based multi-criteria decision framework to prioritize environmental monitoring sites in coastal military units of Vinh Long Province (formerly Tra Vinh Province), Vietnam. Six criteria including environmental baseline characteristics, pollutant accumulation potential, representativeness, impact on military/defense activities, accessibility and operatability, and ecological-social sensitivity were integrated and weighted separately for soil, surface water, and groundwater. A total of 346 candidate locations across 22 military bases were evaluated using field surveys, environmental datasets, and spatial analysis. The model identified 286 priority sites (82.6%) for monitoring, including 110 surface water, 110 groundwater, and 66 soil locations, with higher priority scores concentrated in technical and production units associated with greater pollution risk. Unlike conventional WLC applications, the proposed framework incorporates military-operational sensitivity and medium-specific weighting, enabling more realistic prioritization of monitoring sites in defense-managed environments. The approach provides a transparent and transferable tool for optimizing environmental monitoring networks in military-controlled coastal regions.

Study on factors affecting the nickel plating process on titanium alloy substrates

2026-03-05T08:54:43+00:00

This paper presents the results of research on the factors influencing the electroless nickel plating process on BT6 titanium alloy. Prior to plating, the titanium alloy surface is activated, etched, and zincated using a solution consisting of ZnF₂ (85 g/L), HF (40%, (60 g/L), and Ethylene glycol (500 mL/L) at a temperature of 25 °C for 1 minute. The electroless nickel plating is performed using a solution of NiCl₂ (10 ÷ 50 g/L), KF (10 g/L), and Glycine (30 g/L) with a pH of 2.8 ÷ 3.2. Research results indicate that at a NiCl₂ salt content of 20 ÷ 30 g/L and a plating time of 10 ÷ 15 minutes, the coating surface is quite smooth and uniform, with nickel crystals tightly adhered to the surface. Post-plating heat treatment conducted between 400 ÷ 415 °C promotes the formation of intermetallic phases and transition zones between the layers, enhancing the durability of the Ni coating on the titanium alloy substrate.

Design and numerical aerodynamic analysis of a centrifugal compressor impeller for a 100 kgf-thrust gas turbine engine

2026-04-06T09:49:55+00:00

Small gas turbine engines with 100 kg thrust are increasingly used in unmanned aerial vehicles (UAVs) and small aerospace propulsion systems. In these engines, centrifugal compressors are preferred for their compact design, high compression ratio, and high isothermal efficiency. This study presents the preliminary design and computational fluid dynamics (CFD)-based aerodynamic investigation of a centrifugal compressor impeller. A complete three-dimensional geometry was developed from the target operating parameters, and Reynolds-averaged Navier-Stokes simulations with k-SST turbulence modeling were performed to analyze the internal flow field and evaluate the impeller's aerodynamic performance. The numerical results showed that the total pressure ratio and efficiency were 4.505 and 85.007% at the design point, and the near-stall margin achieved at 18.056% within the typical requirements of a gas turbine engine compressor.

The internal ballistics analysis of underwater solid motor with protective nozzle caps

2026-01-26T07:18:38+00:00

This paper investigates the performance of a solid motor (SM) operating in underwater environments, specifically accounting for the influence of the protective nozzle closure cap assembly. A mathematical model for the internal ballistics is established, incorporating the critical phase of the seal-breaking process. During this stage, the partial combustion of the propellant increases the combustion chamber pressure, leading to the failure of the pressure seal. Concurrently, a portion of the combustion gas flows into the cavity formed between the closure cap and the nozzle, resulting in a pressure buildup within this region. Once the pressure in the low-pressure cavity reaches a threshold sufficient to shear the retaining bolts, the closure cap is jettisoned. Following the ejection of the cap, the combustion gases are discharged through the nozzle into the surrounding medium, transitioning the SM into its conventional operating mode. The findings of this study provide a theoretical foundation for the calculation, design, and structural fabrication of a solid motor intended for underwater applications.

Experimental study to determine the oscillation of the base vehicle and cable tension during the TMM-3M bridge lowering process

2026-03-22T07:48:13+00:00

This paper presents the results of an experimental study on the dynamics of a TMM-3M heavy mechanized bridge vehicle during its lowering phase. A specialized measurement system was designed and deployed on the actual equipment to simultaneously record two key parameters: the vertical oscillation of the base vehicle and the tension of the drive cable. The experimental results show a high degree of agreement with previously established theoretical models. The findings reveal that the vertical displacement of the base vehicle's chassis has an average error of approximately 6% compared to the theoretical model. Additionally, the cable tension increases nearly linearly, with an average error of 6.4% throughout the entire lowering process. This study not only validates the accuracy of the dynamic models but also provides a scientific basis for assessing the structural safety and operational reliability of the equipment. The research results not only help validate the theoretical model but also provide a practical basis for assessing the operational safety of the equipment in terms of cable tension.

Impact of ascorbic acid concentration on the survival rate of saccharomyces cerevisiae under gamma irradiation

2026-02-09T03:51:23+00:00

Ionizing radiation induces severe oxidative stress, leading to cytotoxicity. This study investigates the radioprotective mechanism of Ascorbic Acid (AA) on Saccharomyces cerevisiae exposed to Cobalt-60 gamma irradiation. Yeast cells were treated with AA concentrations (300 µM) and subjected to radiation doses ranging from 25 to 100 Gy. Survival rates were quantified via colony formation assays and analyzed in comparison with previous studies on DNA single-strand breaks (SSB). While prior research demonstrated that AA consistently mitigates DNA damage, the current cellular results reveal a dose-dependent limitation. Specifically, 300 µM AA exhibited significant radioprotective efficacy at a low dose (25 Gy). However, at higher doses (75 - 100 Gy), AA paradoxically reduced survival rates compared to controls, diverging from its protective trend on DNA. The data may suggest a trend towards a functional transition of AA from an antioxidant to a pro-oxidant role, particularly when combined with high radiation doses. Consequently, the study implies that radioprotection observed at the molecular DNA level might not necessarily guarantee cellular survival under extreme oxidative conditions.

Proposing a solution to keep the order of the generating element secret to enhance the security of the digital signature scheme

2026-02-04T08:03:52+00:00

Publicising the order of the generating element can sometimes cause a security risk for a digital signature scheme. Our proposed solution is a new digital signature scheme, in which the order of the generating element is kept secret. So, the proposed new digital signature scheme is more secure than the variants of the same type of digital signature scheme. Furthermore, the speed of computing of our scheme is faster than that of some similar schemes. For this reason, it can be applied in practice.