This paper presents a data structure for voxel volume, which represents voxels with little memory, and an algorithm for generating procedural voxel terrain is described in detail, which is based on the data structure. In addition, a multilevel voxel algorithm is explained for minimizing memory usage and real-time rendering. In the generation algorithm for procedural voxel terrain, the Perlin noise function is used to calculate the height data required for terrain generation, and the multilevel algorithm proposed in this paper creates multilevel voxel volumes by multiplying the generated point data by a translation matrix and a scale matrix. The validity of the two algorithms presented in this paper is verified through application examples, and the possibility can be confirmed through performance verification.

Newly, this paper presented the changing characteristics of meteorological data(solar insolation, dry-bulb temperature, relative humidity, wind speed, cloud cover, and duration of sunshine) measured on Jeju-Island(Jeju-si, Gosan, Seongsan, and Seogwipo-si) and were quantitatively analyzed since 2000. These characteristics were compared with data for six inland regions shown in Reference #4. Through this comparison, differences between Jeju Island's data and inland areas were identified and presented.

In order to amplify magnetic force in a linear magnetic gear, the high-speed magnet must move more than the low-speed magnet by the amplification ratio. Due to limitations in overall size, this topology has limited applications. In this study, we introduce an active magnetic gear that implements a moving magnetic field instead of the mechanical movement of the magnet by replacing the high-speed side magnet with a linear coil. In the proposed system, a harmonic modulator is added to increase the number of poles of the low-speed magnet, thereby suppressing the decrease in magnetic field strength due to size limitations of the low-speed magnet. The possibility of replacing the existing system was confirmed through harmonic magnetic analysis in the air gap, and the magnetic force change characteristics according to the added modulator variable were simulated.

The driving system of an electric vehicle, which is composed of a battery, a motor, and motor control units, generates overheating due to inevitable electrical loads. Since this overheating is caused by the performance degradation of each component, it is important to maintain an appropriate temperature. In order to solve the issue of performance degradation due to overheating of the motor control units, an optimal cooling system was designed through performance comparison tests of each cooling systems under real-driving conditions. It was expected that constructing a thermal management system, which is a core technology of electric vehicles, improves the durability of the vehicle. It was found that maintaining an appropriate temperature was difficult by circulating cooling water solely through a water pump in a student EV car; therefore, a system that radiates coolant, such as a radiator, needed to be added.

This research presents a method for calculating the fitted curve through the displacement response in order to predict the damping coefficient of the suspension mounted a self-made electric vehicle. A lever system was developed to apply the tensile force of the suspension device, and the displacement response of the step function was calculated by modeling the lever system as a 1-DOF system. The exponential-function fitting curve for time was predicted by using the peak data of the displacement response, and the damping rate was calculated through the time constant and the resonance frequency. The lever system was assumed to be a rigid beam in consideration of the actual jig shape and compared with the step function response of the 1-DOF system through a rigid body dynamics simulation. As a result of comparing the fitting curves, the actual lever system shape and the damping rate of the 1-DOF system were predicted similarly. In order to verify the previously developed damping rate prediction method, an actual lever system was manufactured to measure the acceleration response, and the damping rate was predicted through the curve fitting. The accuracy of the proposed prediction method was verified by comparing the correlation coefficient between the curve fitting and the acceleration response data.

This paper presents the effects of the computational time delay and outputs with multi-rate sampling on the stability of a virtual object. The haptic system includes a haptic device with a mass and a damper, a virtual object modeled as a virtual spring, a computational time delay model, a low-frequency sampling and a high-frequency zero-order-hold. The low-frequency sampling time is assumed to be as much as a computational time delay. The relation among the maximum available stiffness, the computational time delay, the low-frequency sampling, and the ratio of the high-frequency sampling to the low-frequency sampling is analyzed using simulations. As the computational time delay increases, the maximal available stiffness of a virtual object is reduced reversely. The stability region can be increased to 135% ~148% of the value in the previous results using zero-order-hold.

Large-capacity electric motors generate significant heat during operation, which impacts efficiency and durability due to increased resistance, magnetic flux loss, and insulation degradation. This study addresses these issues by analyzing the effects of thermal contact resistance, airflow, and ambient temperature on motor temperature distribution. Using finite element analysis (FEM), the study models a 135 kW motor in a cooling tower environment, incorporating different thermal contact resistances and airflow rates, and adjusting external temperatures to observe heat dissipation effects. Results indicate that higher thermal contact resistance causes localized overheating, while increased airflow and controlled ambient temperatures effectively reduce motor temperatures. These findings highlight essential considerations for optimized cooling design, enhancing the performance and lifespan of high-power motors in industrial applications.