The curb weight of electric trucks is more than 10% higher than that of conventional internal combustion engine trucks due to the motor and battery. For this reason, cargo box developed for small electric trucks is required weight reduction, and cargo door that can reduce weight and maintain strength are being developed. In this paper, we designed the lightweight cargo door, confirmed the stability of the door through structural analysis, and developed a cargo box door that was more than 25% lighter by applying composite materials such as Sheet Molding Compound(SMC) and Fiber Reinforced Plastic(FRP).

A study has been conducted on the structural analysis to reduce the light weight of the electric vehicle rotor shaft. ANSYS Static Structural was used for structural analysis. For weight reduction, the solid shaft was converted into a hollow shaft. The yield strength of the existing material SCM 440 is 655MPa, but to increase its safety, the yield strength is changed to 1,030MPa with SCM822H. At this time, weight reduction of about 47% was achieved. The resonance frequency of the rotor shaft was determined by vibration analysis and the structural safety was analyzed.

The objective of this study was to analyse the antivibration characteristics of gloves by frequency band while operating light-weighted powered hand grinder. A methodology to estimate vibration isolation effectiveness of gloves was proposed on the basis of overall R.M.S. transmissibility characteristics. And overall R.M.S. transmissibilities of L-, M- and H-spectra were compared. Electric hand grinder was tested in the laboratory and attenuation performances of 3 different gloves(full finger antivibration glove, open finger antivibration glove, and cotton glove) were considered. Eight healthy male subjects were employed to polish metal plate with a tool. The results indicate that there was no significant difference among antivibration characteristics by frequency bands while operating light-weighted electric hand grinder.

제주도 연안 정치망어장에 다량 내유아여 어획되고 있는 전갱이,고등어, 오징어를 실험어로 하여 백열등에 의한 어군의 유집효과와 어군의 유도 효과에 관한 실험을제주대학교 해양연구소 옥외 수조에서 실시한결과를 요약하면 다음과 같다. 1. 백열등에 대한 전갱이, 고등어, 오징어 어군의 행동은 백열등에 잘 유집되는 경향을 보였으나, 백열등에 대해서 유집하는 적정조도와 반은행동은 어종에 따라 조금씩 다른 경향을 보였다. 2. 유도등을 한 등씩 순차적으로 점등후 소등하는 방법에 의한 전갱이, 고등어, 오징어어군의 행동양식은 어종에 따라서 약간 다르지만, 이들 어군을 목적지까지 유도할 수 있었다. 3. 유도등 3개를 모두 점등한 후 1번 등부터 순차적으로 한 등씩 소등하는 방법에 의한 전갱이, 고등어, 오징어 어군의 행동양식은 어종에 따라서 약간 다르지만, 이들 어군을 목적지까지 유도할 수 있었다. 4. 백열등의 이동에 의한 전갱이, 고등어, 오징어 어군의 행동양식은 어종에 따라서 약간 다르지만, 이들 어군을 목적지까지 유도할 수 있었다.