To improve vibration reduction in the railway vehicle, the semi-active suspension system using MR damper was developed and the vibration performance of the passive suspension system and a semi-active MR suspension system was compared. For the experiment, the MR damper and suspension system were designed and manufactured. Tensile and compression tests were performed on the MR damper while varying the input current. The damping force of the MR damper was measured and analyzed using the Bingham model. The railway vehicle was modeled with 9 degrees of freedom, and the sky hook control algorithm was simulated using the MR damper, using the Bingham model. This verified the effectiveness of the sky hook controller. Furthermore, to compare the vibration performance of the railway vehicle, the driving test was conducted with the MR damper and the passive damper. The lateral acceleration vibration reduction performance of the suspension system with MR dampers and passive dampers was verified, and it was confirmed that the vibration reduction performance of the vehicle with the semi-active suspension system using MR damper was approximately 50% better than that of the vehicle with the passive damper.

This study presents the design and application of an integrated control logic architecture for a 300BPD ES-SAGD(Expanding Solvent Steam-Assisted Gravity Drainage) demonstration plant, aimed at ensuring operational stability and efficiency. With the global expansion of unconventional oil resource development, ES-SAGD is recognized as a technology advantageous for reducing viscosity and improving energy efficiency compared to conventional SAGD. In this research, the plant process was analyzed to identify key control variables and potential risk factors, and a control logic structure integrating supervisory and unit-level control was designed. The stability and reliability of the control logic were validated through Hardware-in-the-Loop Simulation(HILS) and field implementation. The findings are expected to contribute to safer operation, reduced commissioning periods, and enhanced automation in future oil sands demonstration and commercial plants.

This study analyzes the automotive behavior and its impact on driving safety when the Micro controller Unit (Micom), a core component of the automotive Engine Control Unit (ECU), is exposed to high temperatures. The automotive behavior was observed with and without the ECU housing cover under thermal exposure, and the temperature of the Micom was determined using heat transfer principles. The results showed that with the housing cover in place, a thermal equilibrium was maintained at approximately 160[°C], and the Micom's temperature was about 73[°C], which is within its guaranteed operating limits and did not affect the automotive behavior. When the housing cover was removed, the engine stoped to operate at approximately 220[°C], and it is presumed that the Micom's internal circuitry was damaged. These findings can provide useful quantitative data for future reliability assessments of ECUs and for investigations into sudden unintended acceleration phenomena.

WC–Mo₂C–Co cemented carbides were fabricated to investigate the effects of Mo₂C addition on microstructure and mechanical properties. Dual hard-phase design using WC and Mo₂C was employed to optimize the balance between hardness and toughness. Spark plasma sintering (SPS) was conducted at various temperatures after ball milling, and 1300 °C for 5 min was identified as the optimized sintering condition, achieving complete densification and phase stability. The addition of Mo₂C refined the microstructure by suppressing abnormal WC grain growth through preferential dissolution of Mo₂C into the Co binder. Hardness increased up to 1769 Hv30 due to grain refinement and solid-solution strengthening, while promoted η-phase formation and reduced fracture toughness.The 27Mo₂C composition exhibited the most balanced combination of hardness and toughness. These results demonstrate that controlled Mo₂C addition enables dual hard-phase strengthening and microstructure optimization in WC–Mo₂C–Co carbides for advanced cutting and forming applications.

513 magnesium hydroxide sulfate hydrate (MHSH) and Mg(OH)₂ were synthesized by controlling the pH and concentration using a domestic resource, dolomite (CaMg(CO3)2), as the raw material. The MgSO₄ was extracted by treating dolomite with sulfuric acid under various conditions. Hexagonal plate-shaped Mg(OH)₂ and needle-like 513 MHSH were synthesized under the hydrothermal condition. The morphology of the synthesized materials was controlled by adjusting the pH (SO42-/OH- ratio) and hydrothermal reaction time. As the pH of the solution increased, the formation of plate-like structures became dominant, whereas lower pH values (higher SO42- concentration) led to needle-like forms. The results of the 513 MHSH, which was synthesized using reagents and sea bittern, are consistent with the synthesis conditions, and we observed changes in the length and aspect ratio of the needle-shaped structure in response to adjusting the hydrothermal reaction time.