Earticle

Modern warfare demands a high level of coordination and interoperability among multiple combat vehicles and crew members operating in dynamic and complex environments. Traditional training methods are often limited in scalability, flexibility, and cost-efficiency, making it challenging to effectively prepare forces for future battlefield scenarios. To address these limitations, this study presents the development of a Multiple Combat Vehicle Integrated Training Device, a next-generation simulation-based training system. The MCITD integrates advanced technologies such as Extended Reality, Digital Twin modeling, and Artificial Intelligence to deliver immersive, interactive, and highly realistic training experiences. The system allows for simultaneous training of multiple crew members in a networked environment that replicates real-world combat conditions, including terrain, weather, and adversary behavior. Key system components, including the simulation module, network communication framework, battlefield environment generator, and performance analysis engine, are discussed in detail. Potential application scenarios such as large-scale land operations, urban warfare, and multinational joint training exercises are also explored. The MCITD aims to enhance combat readiness, mission success, and training efficiency by providing a cost-effective, scalable, and adaptable solution for future-oriented military training programs.

In this study, a thermal-fluid-structure coupled analysis was performed to improve the thermal performance of a burner for a coal gasification power plant. After combustion analysis, an average temperature of 1,400°C was obtained, closely matching the actual coal gasification system environment. The highest burner tip surface temperature, 887°C, was achieved at the analysis variable, a coal fines inflow velocity of 8m/s. This temperature was mapped to a thermal-structural analysis model, and by increasing the radius of the cooling channel inside the burner to 5 mm, the analysis confirmed a reduction in thermal stress of approximately 20%. In particular, changing the material to HP50-Nb resulted in significantly superior cooling efficiency compared to Inconel 718 without any cooling channel design. The results of this study will be useful for the optimal design of coal gasification facilities as well as for improving the durability of the facilities.

This study presents a standalone diagnostic device for HEV high-voltage battery packs that communicates directly with the BMS outside the vehicle and enables quantitative verification of BMS SOC and SOH outputs. The prototype, developed for a Renault CMA HEV pack, activates the BMS via the low-voltage harness, reads key variables such as SOC, SOH, cell voltage and temperature, and pack voltage and current over CAN, and safely controls the pack’s high-voltage relay. Using a pack reported as 100% SOH by the BMS, constant- current discharge at about a 0.1 C-rate was performed in the SOC range from 30% to 45%, and for 5, 10 and 15-minute segments the usable energy estimated from the BMS SOC and the rated capacity showed mean values around 1.54kWh with a coefficient of variation of approximately 2-3%. The proposed BMS-linked evaluation equipment estimates the usable capacity within a tolerance consistent with the manufacturer’s nominal specification and can serve as a practical basis and tool for second-life evaluation of used high voltage battery packs.

This study investigates the deformation behavior of AH32 steel plates under various line heating conditions in the post line-heating process. A total of 24 experimental cases were conducted by varying material thickness (12mm, 16mm, 20mm), heating speed, oxygen and acetylene flow rates, and torch tip size. Deformation was measured at 35 points per specimen, with emphasis on the maximum deformation at the 300mm X-axis location. The deformation results were classified into three groups: high (≥4.0mm), medium (2.0–3.9mm), and low (≤1.0mm). The results confirmed that material thickness had the greatest effect on deformation, followed by heat input parameters such as heating speed and gas flow rate. High deformation occurred under low heating speed and high flow rate conditions, while low deformation was observed in thick plates with fast heating and low flow rates. These findings highlight the importance of controlling heat input and geometric factors for deformation correction. The data acquired from this study can be utilized as a reference for optimizing automated post line-heating processes in shipbuilding.

Recent tactical vehicle development has focused on balancing protection and mobility through reinforced hulls, modular armor, and advanced mission systems. These upgrades have inevitably increased the gross vehicle weight (GVW), demanding higher engine performance to maintain mobility. This study analyzes the relationship between GVW, engine power, and power-to-weight ratio (P/W) across various international tactical and MRAP vehicles to assess how technological progress has compensated for weight growth. The GVW–power correlation illustrates generational trends in powertrain scaling, while the GVW–P/W analysis reveals changes in mobility efficiency as protection and payload increased. Results indicate that although engine outputs have risen in proportion to GVW, the overall P/W ratio has gradually declined, implying a design shift toward protection-oriented configurations. From these findings, a reference range of 20–25 hp/t is suggested as an appropriate target for future 4×4 and medium-class tactical vehicles. The results provide a quantitative basis for achieving an optimal balance between protection, payload capacity, and mobility in next-generation military vehicle design.

This study investigates the effects of digital interface structure on the operational performance of unmanned and manned–unmanned integrated mechanical systems from a human factors perspective. Using case-based comparative analysis, changes in response time, operation error rate, and situational awareness accuracy before and after interface redesign were examined. The results indicate that improvements in interface integration, procedural simplification, and consistency significantly enhance operational performance without modifying mechanical hardware or control algorithms. The study highlights the importance of incorporating human factors engineering into the early design and evaluation stages of complex mechanical systems.

This research presents a GRNN(General regression neural network) approach for modeling the high temperature deformation flow behavior of 316L stainless steel under 800℃, 900℃ and 1000℃ and strain rates of 0.0002/s, 0.002/s and 0.02/s. There are many machine learning approaches of modeling the hot deformation of metallic alloys. Among them, the neural network approach is one of the most popular. However, the neural network approach takes a relatively long time and effort to compose and optimize the final model. In this research, GRNN is applied to study its applicability for modeling the hot deformation flow stress behavior. The prediction results were studied by calculating various types of error and observing the distribution of prediction error. The predicted results by the GRNN were very accurate and the GRNN was found to be highly applicable to modeling the flow stress of the hot deformation of 316L stainless steel.

This paper presents an AI-based PHM (Prognostics and Health Management) framework for quantitative motor health assessment and remaining useful life (RUL) prediction. The proposed method first defines a health index using vibration and current signals of an industrial motor, and then adopts a two-stage PHM architecture consisting of health-state classification and deep learning-based RUL prediction. A degradation test bench is designed to obtain condition monitoring data for normal, warning, and critical states, and a hybrid 1D CNN–BiLSTM–attention model is developed to capture both local features and long-term temporal dependencies. Experimental results demonstrate that the proposed model outperforms conventional SVM and single LSTM baselines in terms of both health-state classification accuracy and RUL prediction accuracy, achieving a 20–30% reduction in RMSE and more than 80% of RUL predictions within ±10% error. The proposed approach provides a practical PHM framework and modeling guidelines for implementing condition-based maintenance of electric motors in smart manufacturing environments.

This study investigates the flow characteristics of asymmetric multi-stage orifices using computational fluid dynamics (CFD). Three-dimensional models with two to four asymmetric orifices were developed in ANSYS Workbench, and a transient analysis was conducted with the SST turbulence model. Sweep mesh and inflation mesh techniques were applied to capture the flow behaviors near the orifices and within the boundary layer. The results showed that the outlet pressure decreased as the number of asymmetric stages increased. Pressure hunting analysis revealed that the two-stage model exhibited the most stable performance with minimal fluctuation, while the three- and four-stage models showed higher amplitude variations. Velocity distribution and turbulence characteristics confirmed that additional stages increased the maximum velocity and eddy viscosity, and complex streamlines were observed near the orifices. These findings provide insights into the design and optimization of multi-stage asymmetric orifices for stable fluid flow control.

Performance of the hydrogen fuel cell system in a compact special vehicle is mainly influenced by the thermal characteristics of heat release through air flow with electrochemical mechanisms. In this study, numerical analysis has been carried out to investigate air flow and heat transfer characteristics near the fuel cell system for various operating conditions. The cooling characteristics around the radiator system depend on air flow generated by vehicle movement, and the effects of vehicle-induced air flow on the velocity and temperature distributions within the heat release system were examined. These results showed that there are quite complicated air flow around the radiator and fan near the fuel cell system in the vehicle cargo area, and its efficient flow field resulted in cooling performance improvement with driving speed. Hence overall heat release characteristics of the hydrogen fuel cell system are strongly associated with various air flow behavior formed around the compact special vehicle including cargo area.

Exposure to extremely low frequency (ELF) electromagnetic fields (EMFs) from power transmission and distribution facilities has gained increasing attention with rising power demand driven by artificial intelligence (AI). This study proposes a practical EMF measurement method suitable for domestic power facility environments in Korea. Field measurements were conducted on 345 kV and 154 kV overhead transmission lines and 22.9 kV distribution lines based on ICNIRP guidelines and international standards IEC 62110 and IEEE Std 644. Measurements were performed at the maximum sag point at different lateral distances and representative heights. The results show that EMF levels were highest directly beneath the conductors and decreased rapidly with distance, while all measured values remained well below domestic exposure limits.

The renewable energy has, currently, been used because of its eco-friendly energy such as no emission gas and less environmental pollution. Fuel cell electric vehicle (FCEV) using polymer electrolyte membrane fuel cell (PEMFC) uses the hydrogen as fuel to obtain the power by electrochemical reaction. The objective of this study is to investigate the flow characteristics of the hydrogen according to entrainment ratio for ejector of FCEV through comparison analysis with the air. As the results, the flow of hydrogen in ejector corresponds to turbulence with Reynold number 18,093. The pressure difference of the hydrogen between primary flow and secondary flow in ejector was about 16 times compared with that of the air. The mean velocity of the hydrogen in ejector outlet was faster about 15 times than the air.

An exergy analysis of cascade refrigeration system with R744 and R717 is presented in this paper to optimize the design and operating parameters of the system. The design for the operating parameters considered in this study include superheating and subcooling degree, cascade heat exchanger and compression efficiency, condensation and evaporation temperature in the R717 high temperature cycle and R744 low temperature cycle, respectively. The main results are summarized as follows : As the cascade evaporation temperature increases, the COP of R717 high temperature cycle increases. But the COP of R744 low temperature cycle decreases, and the COP of total cascade cycle is almost constant. As cascade evaporation temperature increase, the exergy loss in the R717 condenser and the R744 cascade heat exchanger is the largest and the lowest among all components, respectively. Therefore, in order to improve the COP of total cascade cycle and exergy efficiency() of cascade refrigeration system with R744 and R717, the exergy loss of the condenser and compressor of R717 must be reduced.

This study investigates hybrid propulsion for UAM & AAM as demand shifts toward short-range urban and suburban mobility enabled by advances in lightweight aircraft technologies. Urban low-altitude operations with frequent takeoffs and landings under stricter noise regulations require both high propulsion efficiency and low acoustic emissions. While electric propulsion provides precise controllability and low vibration, limitations in battery energy density and charging infrastructure constrain range, endurance, and turnaround. Hybrid propulsion can mitigate these constraints by combining the high energy density of fuel with the motor’s low-noise, fast-response operation. Accordingly, this study quantitatively compares thrust performance and noise spectra of an identical propeller when driven by an electric motor versus an internal combustion engine, providing baseline evidence to support hybrid propulsion system design.

This study presents an optimization model for battery scheduling in Advanced Air Mobility (AAM) operations considering congested (peak-hour) flight periods. Peak-hour demand concentration causes bottlenecks in vertiport charging/swapping facilities and accelerates battery degradation, reducing operational efficiency. A Mixed-Integer Linear Programming (MILP) model is developed, incorporating battery states (SoC, SoH), charger and swap-bay constraints, and power peak limits. Simulation results under peak and off-peak scenarios show that the proposed model reduces both delay time and total operating cost compared to average-demand scheduling. This study provides a quantitative decision-making basis for enhancing resource efficiency in AAM operations. The findings offer practical implications for improving AAM infrastructure efficiency and resource management policies.

To mitigate power transmission losses between power plants and consumers, Medium-Voltage Direct Current (MVDC) systems, which transmit power as DC and convert it back to AC at the destination, are increasingly being developed. However, these MVDC conversion systems, which are rich in semiconductor devices, generate significantly more heat than conventional transformers. Consequently, the thermal management capabilities of traditional air-cooling methods are proving insufficient, necessitating the adoption of liquid cooling systems. This study aims to optimize the energy efficiency of MVDC liquid cooling systems. Finally, we demonstrated a optimized system that minimizes the pump's power consumption by dynamically adjusting the coolant flow rate to each thermal module based on the automatic control valve system.

The aim of this study was to evaluate the analytical performance of a curved capillary configurations on a U-tube structure used in a tabletop fully automated blood viscometer. Precision was assessed using normal and abnormal quality control materials measured repeatedly over 20 days across shear rates of 1–1000 s⁻1. Correlation between straight and curved capillary configurations was evaluated. Sample stability was also assessed at shear rates of 1 s⁻1 and 300 s⁻1 over three consecutive days. The curved capillary system demonstrated robust precision, with total coefficients of variation decreasing with increasing shear rate. Strong correlations were observed between straight and curved capillary measurements across all shear rates. Passing– Bablok regression showed slopes close to unity and intercepts near zero, while Bland–Altman analysis revealed minimal bias without shear-dependent trends. Whole blood viscosity remained stable over three days at both low and high shear rates (all p > 0.98). The curved capillary–based U-tube configuration provides analytically equivalent and stable whole blood viscosity measurements compared with conventional straight capillary systems, supporting its suitability for fully automated blood viscometer.

This study examines the dynamic characteristics of an articulated aerial work platform. The platform performs articulated joint motions and telescopic boom extension to access both upper-side and under-structure work areas. The boom system includes two articulated joints with slewing rotation, and the tip section is a multi-stage telescopic boom. Component-level dynamics of three telescopic boom components made of Strenx 960 were compared with the system-level dynamics of the fully assembled vehicle. Natural frequencies and mode shapes up to the second mode were obtained through experimental modal analysis based on frequency response functions (FRFs). For the assembled vehicle, tri-axial acceleration responses were transformed into the frequency domain using FFT, and dominant natural frequencies were identified from the spectra. The results show a clear separation between the two levels. The component-level dynamics appeared in the tens-of-hertz range. In contrast, the dominant system-level natural frequencies were observed in the low-frequency range (near 1 Hz). These findings indicate that the assembled system exhibits dominant dynamics distinct from those of individual boom components. They also highlight the need for system-level considerations when interpreting dynamic performance under practical operating conditions.

Tire noise is one of major causes of vehicle noise, and urban traffic noise pollution is becoming more and more serious as the number of vehicles continues to increase. Especially in the age of electric vehicles, improvement of tire noise is getting more important. Especially during highway driving, the noise from the tire became the main noise source of the vehicle. Tire noise is generated from the mutual friction between the tire and the road surface when driving. In this paper, we analyze various factors affecting tire noise generation, reduce environmental noise pollution, and increase ride comfort. The EU carried out the EC 1222/2009 tire labeling system in 2012, which was a severe blow to the tire exporting countries of all countries due to the stringent demand for tire noise. In this paper, 5 tires from 3 countries were selected and selected as test subjects. The purpose of this study is to analyze the noise of road / tire noise according to road condition of each tire.

This study was conducted to explore ways to improve the operation of NCS-based curricula, focusing on vocational education programs. The purpose is to design and establish an effective NCS-based vocational education curriculum and to apply it in educational settings. For the purpose of improving the operation of NCS-based curricula, this study first reviewed the relevant information and system operations presented on the National Competency Standards (NCS) website (http://www.ncs.go.kr/). This is because effective vocational education can only be achieved when accurate information regarding the curriculum and educational content is properly delivered. In conclusion, it is required to identify the problems in the design, composition, and operation of vocational education curricula, and to establish curriculum design strategies that can enhance the overall efficiency of vocational education programs. Based on the results of this study, the research examined the competency unit “Inspection of Aircraft Reciprocating Engine Fuel Systems” under the NCS categories — Major Category [15. Machinery], Subcategory [09. Aircraft Manufacturing], Minor Category [03. Aircraft Maintenance], and Detailed Category [03. Aircraft Reciprocating Engine Maintenance] — and designed the learning content for the NCS learning module “Inspecting the Boost Pump.” The designed practical training plan has the following characteristics: First, by incorporating additional content from the NCS competency unit, it was structured to be applicable in actual workplaces that operate aircraft equipped with reciprocating engines. Second, it aims to enhance troubleshooting skills required for the maintenance of aircraft reciprocating engines. Third, the contents were designed to align with the practical training environments of educational institutions while ensuring applicability to real-world work settings. Fourth, it was designed to allow learners to simultaneously practice content related to obtaining aviation-related certifications. This study is significant in that it designed a vocational education curriculum and proposed effective strategies for improving vocational education. However, there are certain limitations. The study did not include an empirical implementation or analysis of the results based on the designed instructional program. In addition, it did not develop curricula that reflect the specific characteristics of individual subjects within the field of NCS-based aircraft maintenance through the design of diverse course modules.

In the fabrication of curved steel plates for shipbuilding, post line-heating is widely used to induce plastic deformation by applying local heat and controlling residual stress. However, the process is still dependent on skilled labor and empirical methods, making it difficult to ensure consistent quality and precision. To improve the automation and standardization of the post line-heating process, this study aims to investigate the relationship between heating conditions and the resulting deformation behavior of marine structural steel plates. Experiments were conducted on AH36 steel specimens under 24 different heating conditions, including three plate thicknesses (12mm, 16mm, 20mm), two heating speeds, two gas flow ratios, and two torch tip types. Maximum deformation was measured across 15 locations per case. The results showed that thinner plates exhibited greater deformation, and higher heat input—such as slower heating speed and higher gas flow—led to increased deformation. The 800-type torch tip, with a narrower flame focus, also induced larger deformation than the 1000-type. These findings provide fundamental data for optimizing post line-heating parameters and establishing automated correction processes in shipbuilding applications.

In order to study the noise propagation characteristics and noise evaluation of military helicopters, this study conducted continuous noise monitoring of 20 noise-sensitive areas within 3 km around a military heliport in South Korea over a period of 5 days, and the results showed that the noise values at the 20 measurement points around the military heliport were lower than the limit of WECPNL 75 stipulated in the standard for civil airports, and it was found that the maximum noise level had the greatest influence on the evaluation indexes. The study found that the maximum noise level has the greatest influence on the evaluation index. At the same time, the analysis of the noise source spectrum shows that the helicopter noise is dominated by low and medium frequencies, and the low-frequency noise is more irritating in a short period of time.

We developed a device that can screen for shape and surface defects that may occur during the manufacturing process, and can be used for quality inspection during the production process. A non-contact vision system was used for shape quality inspection to check sphericity and concentricity. Shape size was measured to determine whether the defects were within acceptable limits. Even for products that passed shape quality inspection, surface defects could prevent valve sealing. Therefore, the sealing performance of the armature was verified by examining the pressure changes in the air supply section using high-pressure air pressure applied to each assembled valve. To assess the reliability of the inspection device for tip-type armature defects, various defective products were artificially mixed and tested in random order. The results showed that the 100% detection rate for armature defects confirmed its suitability for tip-type armature quality inspection.

The FOPLP method, which uses a square metal carrier to arrange semiconductor chips, offers significantly superior productivity and efficiency compared to conventional processes. However, metal carriers are prone to warping, dents and scratches due to thermal deformation, making surface inspection and correction work essential. Therefore, this study designed and fabricated a gantry guide capable of mounting an indicator and a vision module to effectively inspect the metal carrier surface and improve quality, then evaluated its performance. In the experiment, the gantry system’s performance was verified by evaluating its repeatability precision, and the vision module ensured data reliability through precision at four different magnifications.

The starter motor for military armored vehicles was known for its reliable quality, with less than one failure reported per year. However, this changed recently when a sudden wave of failures began to occur. The main issue was the “pinion gear teeth” snapping off during operation. When these teeth break, the metal fragments scatter and damage other internal parts, causing expensive repairs and leaving the vehicles unusable. Because it is vital for the military to keep these vehicles ready for action, solving this problem became a top priority. This paper provides a comprehensive investigation into the root causes of these pinion gear failures by examining the entire system from multiple perspectives. First, we conducted a detailed analysis of the individual component, including its material properties and the manufacturing process to identify any inconsistencies. Second, the study evaluates the gear meshing conditions and structural alignment with the mating components to ensure proper power transmission. Furthermore, we analyzed the electrical characteristics of the starter motor, such as current surges during ignition, which could impose excessive stress on the gear teeth. By integrating these findings, this paper discusses the comprehensive process of identifying the failure mechanism and proposes technical improvements to prevent future occurrences.

This study investigated the root causes of wheel hub assembly looseness and abnormal brake pad wear observed during a 32,000 km durability driving test of a military medium truck. Structural analysis and component-level durability tests were conducted to identify the failure mechanisms and evaluate improvement measures. Test conditions were established based on relevant regulations and previous studies, and braking force and braking torque equations were derived through mathematical modeling. The results showed that the spacer used to fix the brake disc in the original design did not satisfy the required safety factor greater than 1.0. Furthemore, a wheel hub assembly torque durability test under more severe conditions than the original test was performed, and the results demonstrated a significant improvement in durability perfomance.

This study presents the development and field evaluation of an integrated chopping round baler for summer forage crops such as corn and sudangrass, whose stems are relatively thick and hard. In typical field practice, harvesting, chopping, and baling are carried out by separate machines, increasing operational steps and reducing overall efficiency. To address this limitation, a prototype baler was designed to chop harvested crops and simultaneously suction-feed the material into a round-baling chamber for continuous bale formation. Field test were performed to evaluate practical performance using key indices including bale size consistency, working speed during harvesting, bale production time per unit, and chopped particle length. The developed system produced chopped material with a c relatively uniform particle length below 100 mm. Moreover, the prototype achieved a bale production time of less than 1 min per bale while maintaining a working speed of approximately 5 km/h. The results demonstrate the feasibility of integrating chopping and baling functions into a single system to improve field productivity for summer forage crop handling.