In recent years, the government has strongly promoted multi-purpose utilization of paddy field. However, poor drainage causes waterlogging stress in upland crops, requiring subsurface drainage technology, resulting in high installation and management costs. To address this issue, a low-cost and high-efficiency technique was developed that utilizes wasted coir substrates which have characteristics of high porosity and good drainage, for upland crop cultivation in paddy fields. Soybeans were grown in both paddy soil and wasted coir slab with two planting densities (80×20 cm and 60×20 cm). The results showed that the coir substrates had better performance than the paddy soil in terms of soil physical and chemical properties and the growth and yield of upland crops are improved. The treatments using wasted coir substrate showed a 41.4% increase in yield and a 21.3% increase in protein content compared to PS treatment. Our findings demonstrate that recycling waste coir substrates to grow upland crops is a positive cultivation strategy to solve some drainage problems in paddy fields. This approach offers a sustainable solution for upland crop production while also addressing the issue of waste management in agriculture.

Recently, there has been an increasing demand for independent suspension systems in commercial vehicles, and various researches related to this trend are currently underway. In this study, as part of an effort to localize the independent suspension system for commercial vehicles, a preceding study was conducted to convert the existing forging process into a casting process. The structural stability of the developed product was evaluated by performing stress analysis on both forging and casting materials. In order to compensate for the low yield characteristics of the casting material, design improvements were made to lower the maximum stress level based on numerical simulations.Additionally, Lightweight design was performed, capitalizing on the inherent design flexibility offered by casting products. As a result, it was confirmed that the developed product exhibited similar stress characteristics level to the existing product, along with a weight reduction of approximately 5%.

With the development of drone technology, drones are being used in various industries. In general, drones use lithium-based battery pack, which is sensitive to external impact and temperature characteristics. Therefore, in order to prevent this problem, a battery case for protecting the battery from the outside is used. Usually, carbon fiber is used as case material, carbon fiber is expensive and has disadvantages of being difficult to manufacture. In this study, a battery case was fabricated to minimize the influence of external impact and temperature by using expanded polypropylene material, and also the battery efficiency test was performed using fabricated case. After basic design for battery case was conducted, a system capable of maintaining temperature was constructed by attaching a surface heating element inside the case, and the effect of maintaining temperature according to the presence or absence of the case was confirmed. Using manufactured prototype case, flight tests were carried out to check the battery voltage level according to the presence or absence of the case and to analyze the effect of improving the battery efficiency for the flight time of the drone.

본 연구는 기존에 절화용으로 개발되지 않았던 벼룩이울타리를 절화로써의 가치와 가능성을 증명함으로써 새로운 관상식물로 개발하기 위해 수행되었다. 실험은 온도, 보존용액, 절화 수명연장제에 따른 절화 벼룩이울타리의 영향을 구명하고자 절화수명, 수분흡수량, 생체중을 조사하였다. 수확 후 절화는 4, 15, 20, 25°C의 온도 조건에 따른 영향력과 1, 3% sucrose 와 8-hydroxqui-noline sulfate(8-HQS) 10, 50, 100mg･L-1 혼 용보존용액, 절화수명연장제 Chrysal와 Floarlife을 처리하였다. 저장 온도에 따른 실험 결과, 절화 벼룩이울타리는 저온 (4°C)에서의 저장에서의 절화수명이 대조구(7.8일)보다 29일 연장되었다. 온도가 낮을수록 절화의 품질과 수명에 가장 효과적이었다. sucrose와 8-HQS의 효과 확인을 위해 가장 낮은 농도의 당과 살균제를 혼용한 1% sucrose+8-HQS 10mg･L-1를 제외한 나머지 3개의 보존용액 대조구(6.5±0.5일)에 비하여 절화수명이 약 2주 연장되었다. 또한, 절화수명연장제 Chrysal 과 Floarlife는 sucrose와 8-HQS의 혼용보존용액과 절화수명에 유의적인 차이는 없었다. 한편, 모든 실험 조건에서 수분흡수량과 생체중의 급격한 감소는 절화수명의 단축됨과 연관이 있다는 것을 확인하였다.