Al-Mg-Si alloys are light weight and have excellent corrosion resistance, and are attracting attention as a liner material for high-pressure hydrogen containers in hydrogen fuel cell vehicles. Because it has excellent plastic hardening properties, it is also applied to car body panel materials, but it is moderate in strength, so research to improve the strength by adding Si-rich or Cu is in progress. So far, the authors have conducted research on the intergranular fracture of alloys with excessive Si addition from the macroscopic mechanical point of view, such as specimen shape. To evaluate their impact tensile properties, the split-Hopkinson bar impact test was performed using thin plate specimens of coarse and fine grain alloys of Al-Mg-X (X = Cr,Si) alloy. The effect of the shape of the specimen on the characteristics was studied through finite element method (FEM) analysis. As a result, it was found that the intergranular fracture of the alloy with excessive Si depended on the specimen width (W)/grain size (d), which can be expressed by the specimen size and grain size. As W/d decreases, the intergranular fracture transforms into a transgranular fracture. As the strain rate increases, the fracture elongation decreases, and the fracture surface of the intergranular fracture becomes more brittle. It was confirmed that intergranular fracture occurred in the high strain rate region even in materials with small grain sizes.

By the recent fast growth of e-commerce markets, it has been stimulated to study order picking systems to improve their efficiency in distribution centers. Many companies and researchers have been developed various types of order picking systems and pursued the corresponding optimal operation policies. However, the performances of the systems with the optimal policies often depend on the structures of the centers and the operation environments. Based on a simulation model that mimics a unique zone picking system operated by a real company in the Republic of Korea, this study compares several operation policies and finds the most appropriate order selection rule and worker assignment policy for the system. Under all scenarios considered in this study, simulation results show that it is recommendable to assign more efficient workers to the zones with heavier workload. It also shows that selecting the order with the maximum number of non-repeatedly visited zones from the order list provides the most consistent and stable performances with respect to flow time, makespan, and utilization of the system even under the scenario with the breakdown zones. On the other hand, selecting the order with the minimum ratio of penalty to the number of zones performs the worst in all scenarios considered.

This study aims to analyze consumer perceptions of the metaverse platform and luxury fashion brands in relation to consumer lifestyles, thereby providing foundational data for future marketing strategies of fashion brands using the metaverse. A survey on the lifestyle and perceptions of the metaverse, as well as on luxury fashion brands, was conducted among 300 men and women between their 20s and 40s. Statistical analyses included frequency analysis, cross-tabulation, chi-square (χ2) analysis, factor analysis, cluster analysis, one-way ANOVA, and Duncan’s post-hoc test. Factor analysis of the participants’ lifestyles revealed five distinct types: “Indifferent,” “Social, individual, and leisure-oriented,” “Trend-leading and brand-oriented,” “Appearance and fashion-oriented,” and “Self-improvement-focused and individualistic” types. The analysis of luxury fashion brand perceptions based on lifestyle types showed that the “Trend-leading and brand-oriented” type had higher awareness and preference for brands such as Gucci, Burberry, and Balenciaga, while the “Indifferent” type showed lower levels of awareness and preference. Regarding brand perception related to luxury fashion brand content experiences within the metaverse, Gucci, Burberry, and Balenciaga showed consistent results across all types. Specifically individuals classified under the “Trend-leading and brand-oriented” category exhibited higher awareness and preference for these brands within metaverse experiences, while those categorized as “Indifferent” displayed comparatively lower levels. Therefore, digital marketing strategies targeting consumers under the “Trend-leading and brandoriented” category are expected to be highly effective for luxury fashion brands. This study is poised to contribute to the expansion of the marketing landscape within the metaverse virtual world for fashion.

Water lettuce (Pistia stratiotes L.) is a free-floating perennial herbaceous plant with rosette leaves and a stem. Although this plant multiplies and has adverse effects on aquatic ecosystems, it can be used for biological purification of polluted water and production of valuable substances as a traditional medicine. In this study, we report a protocol to establish an in vitro micropropagation method based on direct shoot organogenesis from stem explants. In media comprising two types of basal medium and different growth regulators, multiple shoot organogenesis was observed on stems. The micropropagation method was most effective on Schenk and Hildebrandt (SH) medium with 1 mg/L indole-3-acetic acid and 2 mg/L 6-benzylaminopurine supplemented with 30 g/L sucrose, on which all explants produced multiple shoots. The shoots rooted spontaneously on solid half-strength Murashige and Skoog (MS) and SH media without growth regulators (1/2MSO and 1/2SHO). However, roots developed more vigorously in liquid media. Regenerated plants colonized and grew more rapidly in SH basal medium than in MS basal medium and produced 6–8 stolons within 2 weeks on 1/2SHO. In summary, we established a method for micropropagation in vitro through direct organogenesis of water lettuce, which shows the potential of water lettuce as a model aquatic plant for phytochemical and pharmacological research.

Indian meal moth, Plodia interpunctella (Lepidoptera: Pyralidae), is a serious pest of stored products. We assessed the efficacy of combined application of Beauveria bassiana AAD16 and azadirachtin against P. interpunctella under laboratory conditions by using filter paper dipping method. P. interpunctella larvae showed lowest LT50 in combined application of AAD16 and azadirachtin compared to the application of only azadirachtin. The mycosis rate of P. interpunctella larvae was 100% after 14 days of the combined application while AAD16 only application showed 93%. These findings suggest that B. bassiana AAD16 and azadirachtin combined solution can be an effective controlling technique against P. interpunctella larvae.

현재 기후변화 및 산업화 등으로 생물다양성 감소, 환경오염에 대한 위기가 확산되고 있어 지속가능한 미래설 계에 대한 관심이 높아지고 있다. 이에 따라, 본 연구에서는 대표 도시숲인 국립세종수목원에 조성된 총 16개 전시원을 대상으로 총 6차례에 걸쳐 방문곤충과 화분매개곤충 다양성을 조사하였다. 조사시기별 분석결과로 2차(‘23.7.31) 조사 시기에 가장 다양한 종을 확인할 수 있었으며(총 80종), 전시원별 분석결과 숲정원에서 가장 다양한 종을 확인할 수 있었다(총 59종). 또한 주요 식물 6종(배롱나무, 나무수국, 무궁화, 좀개미취, 범부채, 부처 꽃)에 7~10월 기간 중 양봉꿀벌, 애황나나니, 호박벌, 네발나비, 호랑나비, 흰점박이꽃무지, 호리꽃등에, 배짧은 꽃등에가 화분매개 행동을 하는 것을 확인하였다. 본 발표에서는 2023년 국립세종수목원 전시원 내 방문곤충 및 화분매개곤충 다양성 연구의 구체적인 결과를 제시하고, 곤충의 보전 필요성, 도시숲 내 체계적인 방문곤충 및 화분매개곤충 조사의 중요성에 대하여 논하고자 한다.