CFRP composite is widely used in various industries because it has excellent mechanical properties under static load conditions. In particular, the CFRP composite is widely used in the aerospace field due to its superior wear resistance and heat resistance. 
However, under the impact load, temperature and moisture conditions, there is a lot of decrease in strength. In this study, impact experiment were conducted using high-speed impact testing device to examine fracture and dissection of fiber and matrix generated inside the CFRP composite according to the layered composition. In order to establish the conditions of the various specimens, a specimen with the stacking conditions of orthotropic ([0°3/90°3]s) and isotropic ([+45°3/-45°3]s) was constructed. 
It was found that the orthogonal divergence test specimen was more than twice as likely to increase the critical tube energy than the isotropic test specimen.

This study is to examine the structural stability of 200W gyromill type vertical axis wind turbine system. Structural analysis by using commercial software ANSYS is performed to compute the displacement and strength ratio of filament wound composite blades. Evaluate the power performance through analysis and structural integrity through uni-directional FSI analysis in structure design of wind turbine blade. The results of CFD analysis show that the wind turbine reveals an enough structural safety. The maximum structural displacement occurs at trailing edge of blade and the maximum stress occurs at the strut.

In this paper, a mechanism of micro crack sensor based on electrohydrodynamic printing is studied. Inks are made by stirring sufficiently silver nano paste with Alpha-terpineol and BDGA(Diethylene glycol monobutyl ether acetate). The polymer PVP is added to the stirred inks to investigate the effect of the polymer on the droplets discharged. To make the grid type of the sensor, several lines are patterned on the upper and lower surfaces of the structures at regular intervals in the horizontal or vertical direction. It is confirmed that the resistances are changed by generating arbitrary cracks in the grid sensor, and the position of crack occurrence is detected by using the intersection point of the changed resistances.

In this study, a integral type air vent duct body was proposed and flow analysis of injection molding using FEM was performed to improve performance deterioration caused by leakage defect of air vent duct body for automobile. The integral type of air vent duct body was developed in a new shape to be applied to new vehicles in domestic automobile manufacturing company. The leakage test was performed for performance evaluation and the flow analysis of injection molding was performed for new product. The proposed integral type air vent duct body was possible to eliminate the product defects caused by leakage in air vent duct body joint and to optimize the product injection molding process and to make multi product injection molding by the flow analysis. In addition, it was possible to provide application data for predicting feasibility of newly developed products and securing reliability.

Software reliability is one of the most important elements of quality. As the proportion of software in the system increases, the importance of analysis for software reliability is also increasing. In particular, weapon system software in the defense domain requires higher reliability. Therefore, the reliability of software in the development of weapon systems should be strictly analyzed and managed quantitatively However, the conventional reliability analysis of weapon system software is only static analysis at the code level. Therefore, this paper proposes a more systematic and quantitative analysis method for reliability of weapon system software. By showing the actual results applied to OO weapon system development, we can verify the practicality of the analysis model.

In recent years, unmanned aerial vehicles (UAVs) also known as drones have been employed in an agricultural field. Although spray systems have been well developed for general agricultural applications, there are no researches about the spray system for the agricultural drone. In addition, high cost is required to evaluate the spray performance of agricultural drones. In this study, we developed a simulated spray system and an evaluation method for the spray performance of agricultural drones. With a digital image processing, the spray performance was evaluated based on the coefficient of variation and the effective spraying width was calculated. The developed system was verified by on-site test using an evaluation method similar to Foundation of Agricultural Tech Commercialization and Transfer (FATCT). The results of the developed system agree well with that from a field test. The developed system would be useful for designing and evaluating spraying systems for agricultural drones.

In this study, we consider a 4-directional mobility model applicable in the metropolitan area to calculate the number of location registrations per mobile station (MS) for the zone-based (ZBR) and distance-based (DBR) registration schemes. The number of location registrations between two incoming calls are obtained mathematically assuming that the MSs are uniformly distributed in the location area (LA), and the mathematical results are verified through computer simulations. The comparison between analytical results and computer simulations shows that, in ZBR, MSs are uniformly distributed in the LA after turning, but they are not uniformly distributed in LA for DBR. It is also observed by computer simulations that, when the moving distance between turning points is smaller compared to the distance between incoming calls or LA's radius, DBR outperforms ZBR in most cases.

An investigation of microstructure changes in a new, in situ-fabricated, three-dimensionally interconnected graphene-networked Cu composite was performed in relation to the heat treatment temperature in H2 and in air. Heat-treated in H2 revealed that recrystallization commenced at ~ 300 ℃ and the crystal grew afterward. However, the crystal growth was constrained within the initial Cu grains and inhibited due to Cu grains being wrapped by the stable graphene, even at 1000 ℃. This resulted in similar or narrower grain-size distribution. Meanwhile heat treatment in air resulted in the oxidation of carbon, instability of graphene, and crystal growth over the grain boundaries, which resulted in a wider grain-size distribution. Increases in tensile and plastic deformation (30% and 144%, respectively) were observed due to the grain size refinement and the strong interfacial bonds between graphene and the Cu matrix. The result was greater load bearing and toleration of a substantial load during plastic deformation.