Aerial work platform truck is used in various ways depending on the surrounding environment, of city roads, farming areas, and industrial sites. Air flow, drag force and torque in surroundig the flow field of AWP have been analyzed with CFD method. The overall air flow rate decreases as the AWP passes and increases between the vehicle and the boom, at the boom connections, and at the bottom of the work platform. The drag force and torque on the boom, workspace, and the combined boom and workspace are largely affected by air flow velocity. The boom's drag and torque are approximately 2.2 and 1.3 times greater than those of the work platform, respectively. These predicted results can be widely applied as basic conceptual design data for highly efficient aerial work platform truck.

In this study, power generation characteristics based on water flow dynamics in a pipe system with a mobile firefighting robot were analyzed using 3D CAD modeling and computational fluid dynamics(CFD) simulations. The water flow field which is significantly affected by applied pressure, generates mechanical torque at the turbine blades, enabling power generation. The inlet pressure of the flow field was set to approximately 6 to 12 bar, and the flow characteristics such as velocity, pressure, and mass flow rate, along with power generation characteristics, were analyzed under various turbine rotational velocities. It was observed that higher inlet pressures resulted in increased torque and mechanical power output at the turbine blades. This research is expected to serve as a fundamental design and data reference to improve the performance of firefighting robots at fire sites.

A computational analysis was performed to study the thermal characteristics within the injection molding process of polygon mirrors in LiDAR systems. Such polygon mirrors are significantly influenced by the geometric shape of the injection mold as well as temperature and operating conditions. The analysis included the temperature distribution, heat flux, and variations in heat transfer rate of the polygon mirror from initial conditions. From the beginning of the injection process, temperature of the polygon mirror changes rapidly, leading to conductive heat transfer to the mold. There are large variations in the mirror temperature change depending on local position, and surface heat flux are affected by internal cooling path. These results are expected to be used as thermal design data for various polygon mirror processes.

Application areas of floating marine structure systems have been increased with the development of power generation systems using renewable energy. Hence it is necessary to analyze the behavior of these floating systems for efficient design and operation. In this study, a computational analysis was performed to predict the characteristics of mooring lines load variation connected to a floating marine structure with waves. Pressure on the floating body and mooring lines load were analyzed with wave direction and height. The floating body stability severely decreased for 90° of the wave incident direction, and maximum load of the mooring lines increased with the height. These results are expected to be applicable for optimal design of the marine floating system.

본 연구는 사회경제적 지위(socioeconomic status: SES)가 문화적 자기효능감에 미치는 직접적인 영향을, 문화예술 콘텐츠 소비향유와 문화예술 지식을 통해 각각 간접적으로 미치는 영향들과 비교 분석하였다. 이를 통해 사회경제적 지위가 어떤 경로로 통해 문화적 자기효능감을 극대화시킬 수 있는지를 살펴보았다. 본 연구는 전국 단위의 성별·연령별 비례할당에 의한 무작위 표본(N=547) 추출에 근거하여 실증 분석하였다. 연구결과, 첫째 사회경제적 지위는 문화적 자기효능감에 정(+)적 영향을 미쳤을 뿐 아니라, 문화예술 콘텐츠 소비향유와 문화예술 지식을 매개로 하여 문화적 자기효능감에 간접적으로도 정(+)적 영향을 미쳤다. 둘째, 사회경제적 지위가 문화적 자기효능감에 미치는 이들 직간접적인 영향 사이에는 유의미한 크기 차이가 없었다. 셋째, 그러나 사회경제적 지위가 문화예술 콘텐츠 소비향유 활동을 증가시키고, 이것이 문화예술 지식을 높일 경우 문화적 자기효능감은 앞서 직간접적 영향보다 더 크게 증강된다는 사실을 발견하였다. 이는 단순히 사회경제적 지위만으로 문화적 자기효능감이 극대화되지는 않는다는 것을 시사한다. 즉 문화예술 콘텐츠 소비향유 활동과 문화지식의 증가가 같이 수반돼야 한다는 것이다. 끝으로 이론적·현실적 함의를 논의하였다.

The effects of Quenching and Partitioning (Q&P) and Annealed Martensite (AM) heat treatment on the microstructure and tensile properties were investigated for 0.24C-0.5Si-1.5Mn-1Al steels. The Q&P steels were annealed at a single phase (γ) or a dual phase (γ+α), followed by quenching to a temperature between Ms and Mf. Then, enriching carbon was conducted to stabilize the austenite through the partitioning, followed by water quenching. The AM steels were intercritically annealed at a dual phase (γ+α) temperature and austempered at Ms and Ms±50˚C, followed by cooling in oil quenching. The dual phase Q&P steels showed lower tensile strength and yieldyield strength than those of the single phase Q&P steels, and tThe elongation for the dual phase Q&P steel was partitioning 100s higher than that of that for the single phase Q&P steels as the partitioning time was less than 100s up to partitioning 100s. For AM steels, the tensile/yield strength decreased and the total elongation increased as the austempering temperature increased. The stability of the retained austenite controlled the elongation for Q&P steels and the volume fraction of the retained austenite controlled the elongation for AM steels.