This study examines the dynamic characteristics of an articulated aerial work platform. The platform performs articulated joint motions and telescopic boom extension to access both upper-side and under-structure work areas. The boom system includes two articulated joints with slewing rotation, and the tip section is a multi-stage telescopic boom. Component-level dynamics of three telescopic boom components made of Strenx 960 were compared with the system-level dynamics of the fully assembled vehicle. Natural frequencies and mode shapes up to the second mode were obtained through experimental modal analysis based on frequency response functions (FRFs). For the assembled vehicle, tri-axial acceleration responses were transformed into the frequency domain using FFT, and dominant natural frequencies were identified from the spectra. The results show a clear separation between the two levels. The component-level dynamics appeared in the tens-of-hertz range. In contrast, the dominant system-level natural frequencies were observed in the low-frequency range (near 1 Hz). These findings indicate that the assembled system exhibits dominant dynamics distinct from those of individual boom components. They also highlight the need for system-level considerations when interpreting dynamic performance under practical operating conditions.

Although vimentin is widely recognized as a mesenchymal marker, its expression in epithelial cells has been reported in several physiological and pathological conditions. The aim of this study was to investigate the immunoreactivity of vimentin in the epithelial component of benign odontogenic tumors. Immunohistochemistry for vimentin was performed in a total of 28 benign odontogenic tumors consisting of 11 WNT pathway-altered odontogenic tumors (WNT-OTs), 12 ameloblastomas, and 5 adenomatoid odontogenic tumors. All WNT-OTs (11/11), including calcifying odontogenic cyst, dentinogenic ghost cell tumor, and adenoid ameloblastoma, were focally positive for vimentin. Specifically, clear cells in close proximity to dentinoid were consistently positive, a subset of ghost cells were positive with varying degrees of intensity, but morular structures were negative. Two thirds of ameloblastomas (8/12) were focally positive for vimentin, more frequently in peripheral cells or the basal layer than in central cells or the upper layers, respectively. All adenomatoid odontogenic tumors (5/5) were focally positive for vimentin, especially in peripheral anastomosing strands and some cells adjacent to calcifications. Vimentin expression in epithelial cells is a common feature of benign odontogenic tumors. The intratumoral localization of vimentin in WNT-OTs may provide insights into the nature of their histologic components.

본 연구는 청년층을 대상으로 수면의 질이 우울과 어떠한 관련성을 가 지는지 분석하고, 수면의 질을 구성하는 세부 요인들이 우울과 어떤 양 상으로 연결되는지를 규명하고자 수행되었다. 이를 위해 2024년 지역사 회건강조사 자료를 활용하였으며, 만 19세 이상 39세 이하 청년 17,841 명을 분석 대상으로 하였다. 분석 방법으로는 복합표본설계를 반영한 빈 도분석, Rao–Scott χ² 검정, 복합표본 로지스틱 회귀분석을 실시하였다. 연구 결과는 다음과 같다. 첫째, 여성과 낮은 교육수준 집단에서 우울 위 험이 유의하게 높게 나타났다. 둘째, 수면의 질이 저하된 집단에서 우울 군의 비율이 전반적으로 높아, 청년층에서도 수면 문제가 정신건강과 밀 접하게 연관됨이 확인되었다. 셋째, 수면의 질 세부 요인 중 주관적 수면 의 질 저하, 긴 수면 잠복기, 잦은 수면 방해, 수면제 사용, 주간 기능장 애는 인구사회학적 요인을 통제한 이후에도 우울 위험을 유의하게 증가 시키는 요인으로 나타난 반면, 수면 시간과 수면 효율은 유의한 관련성 을 보이지 않았다. 이러한 결과는 청년층 우울을 이해함에 있어 수면을 단순한 시간 개념이 아닌 질적·구성요인별 관점에서 접근할 필요성을 시 사하며, 향후 청년 정신건강 정책과 실천 현장에서 수면 문제 유형을 고 려한 세분화된 평가와 맞춤형 개입 전략의 중요성을 제시한다.

The design code specifies the seismic loads for non-structural components (NSC) regardless of their planar locations. Thus, structures with irregular geometry that exhibit torsional behavior may experience greater seismic loads than those specified by the design code. This study assessed the adequacy of the code-specified equivalent static loads using nonlinear dynamic analysis results from structures intentionally designed to be eccentric, and finally proposed a formula that accounts for torsional amplification effects in buildings. The analysis results indicated that the code-specified equivalent static loads were conservative in the lower stories or near the center of mass. On the other hand, the dynamic analysis-based loads exceeded the equivalent static load in the outer perimeter of the mid- and upper stories. Accordingly, a torsional amplification factor equation was proposed, which is a function of the building's eccentricity ratio and the relative distance from the center of mass. The proposed equation applies to the NSC installed in the stories above the midpoint of the total building height. For a building with zero eccentricity or NSC at the center of mass, the function was set to unity.

As the unmanned aerial vehicle industry grows, unexplained multirotor crashes continue to increase, and existing preventive maintenance methods have limitations in managing multirotor safety. Safety must be the top priority in multi-copter operations. To address this, real-time monitoring of the multi-copter's flight status during operation is required, along with anomaly detection and immediate response based on flight log information. However, limitations exist in processing anomaly data for each flight control log, necessitating the development of standardized technology to overcome this challenge. In this paper we propose a standardized process for collecting multi-copter flight control logs in real time, classifying the log information by message sets, and extracting key defect detection indicators contained in each message set. Furthermore, the extracted defect detection indicators were validated using various supervised learning models. In our experimental results, we collected flight logs from a multi-copter equipped with a defective propeller and conducted experiments using three defect detection models. The results show an accuracy rate of 0.99. This is the F1-score for the defect detection rate.

흰점박이꽃무지(Protaetia brevitarsis) 유충은 고단백·고지방·미네랄이 풍부한 식용곤충으로 기능성 식품 및 사료 소재로 주목받고 있다. 본 연구에서는 열풍건조, 동결건조, 마이크로파건조 세 가지 방법으로 건조한 흰점박이꽃무지 유충의 영양성분과 유해물질 함량을 비교하여, 건조 공 정에 따른 품질 및 안전성 차이를 평가하고자 하였다. 동일한 조건에서 사육한 유충을 각 건조방법으로 처리한 후 수분함량을 보정하여 일반성분, 지방산 조성, 아미노산 조성, 무기질 함량 및 중금속 함량을 분석하였다. 그 결과, 마이크로파건조 처리군은 조단백질(57.6 g/100 g), 조지방(17.7 g/100 g), 올레산(10.5 g/100 g) 함량이 열풍건조 및 동결건조 처리군보다 유의하게 높았고, 식이섬유와 칼슘은 동결건조 처리군에서 가장 높게 나타났다. 모든 처리군에서 중금속 함량은 국내 식용곤충 관리 기준을 충분히 하회하여 안전성이 확보되었다. 이러한 결과는 동결건조가 항상 영양 소 보존에 가장 유리하다는 통념을 보완하며, 건조 효율과 영양 농축 정도가 곤충 체조직 특성과 건조 조건에 따라 달라질 수 있음을 시사한다. 따라 서 흰점박이꽃무지 유충의 가공 과정에서 마이크로파건조는 영양 농축과 품질 확보를 동시에 고려할 수 있는 실용적인 대안 건조공정으로 활용될 수 있을 것으로 판단된다.

Airborne bacteria are an important component of atmospheric fine particulate matter (PM2.5), yet the interactions between microbial communities and organic compounds remain poorly characterized. This study investigated the impact of alkane chain length on bacterial dynamics in outdoor PM2.5 using correlation analysis, generalized additive models, and network-based approaches. Among individual alkane species, C30 (n-triacontane) showed a consistent positive association with bacterial concentration in both simple and partial correlation analyses, whereas C20 (n-eicosane) and C24 (n-tetracosane) exhibited significant negative associations only after controlling for collinearity among alkanes. Grouped alkane classes (C20–C24, C25–C29, C30– C35) did not show statistically significant nonlinear effects on bacterial concentration in models using the full dataset. However, temperature demonstrated a strong nonlinear effect and acted as a modifier of alkane-bacteria relationships. Stratified generalized additive models revealed that under high-temperature conditions (≥ 14oC), all three alkane groups showed significant and localized nonlinear associations with bacterial concentration, with the strongest positive response observed for C30–C35 (p = 0.0011). Network analysis indicated that mid-chain alkanes (C20–C25) were positively linked to metabolically versatile genera such as Pseudomonas, Caldalkalibacillus, Pseudarthrobacter, Pigmentiphaga, and Janthinobacterium, whereas long-chain alkanes (C26–C35) were negatively associated with genera including Methylosinus, Pelomonas, and Pedomicrobium. These results suggest that alkane chain length acts as an ecological filter structuring bacterial communities present in PM2.5 and that hightemperature conditions (≥ 14oC) enhance these interactions by altering alkane phase behavior and particle stability. Understanding these coupled chemical and biological processes is therefore critical for anticipating future changes in air quality and emerging health risks.

Due to the implementation of the Good Agricultural Practices (GAP) scheme, the verification of the microbiological safety of imported agricultural by-products used as mushroom substrates is now concerning. However, basic data on pathogenic fungi remain scarce. In this study, we examined fungal contamination levels (CFU/g) in the agricultural by-products imported in 2017 from Egypt, Germany, India, and Ukraine. Fungal loads ranged from 1.0 × 102 - 6.6 × 104 CFU/g. A total of 25 species across 10 genera were identified, including 21 species from Ascomycota, 3 species from Basidiomycota, and 1 species from Mucoromycota. Some of these species have been known to produce mycotoxins and exhibit pathogenicity toward humans or animals. The results of this study suggest that the fungal contamination in imported agricultural by-products is a critical factor to be considered in mushroom cultivation.

In this study, flavored oils were developed using oak mushroom (Lentinula edodes), with olive, avocado, soybean, and sunflower oils as the carrier oils. Changes in oxidative stability, color, aroma, and taste resulting from infusion with oak mushroom powder were then comparatively evaluated. Across all four oils, the samples infused with oak mushroom powder did not exhibit significant differences in primary and secondary oxidation levels compared with those of the controls; however, in terms of color, browning decreased in olive oil but tended to increase in avocado, soybean, and sunflower oils. Based on the analysis of aromatic characteristics, major sulfur compounds derived from oak mushroom formed in refined soybean and sunflower oils, whereas olive and avocado oils did not exhibit distinct effects. In terms of taste characteristics, umami increased after oak mushroom powder infusion across all oils, and the enhancement of umami was particularly significant in olive and avocado oils. These results indicate that the aromatic and taste characteristics of oak mushroom-flavored oils exhibit different patterns depending on the type of vegetable oil used.

This study evaluated the perception of images and emotions of Korean food in nine countries. Intercultural patterns were identified through PCA and AHC of principal components. Korea showed a traditional-emotional orientation in which images such as “rich in fermented foods”, “nutritionally balanced”, and “various side dishes” were linked to emotions such as “like a mother’s home-cooked meal”, and “sharing affection”. On the other hand, the U.S., Australia, the U.K., Brazil, the United Arab Emirates, Malaysia, the Philippines, and Singapore emphasized sensory-practical aspects, such as “tastes well”, “comfortable”, and “colorful”, and linked them to emotions such as “comfort” and “healthy”. Cluster analysis placed these eight countries in separate clusters, along with Korea. These results highlight the cultural differences in imageemotional interactions and support customized globalization and marketing strategies.

This study examines the seismic vulnerability of non-structural components in high-rise buildings by proposing a normalized floor response spectrum (FRS) suitable for practical application. A Bayesian-mode-based method (BMBM) is used to develop the FRS, incorporating both modal amplification effects and the probabilistic variability observed across different building heights and story levels. The resulting spectrum is methodically compared with existing code-based and empirical methods to assess its consistency, conservatism, and relevance to engineering practices. The findings demonstrate that the proposed FRS provides a realistic yet reliable upper-bound estimate of floor accelerations, particularly in the upper stories where modal interactions are significant. This research offers a robust and practical framework for enhancing the seismic design of nonstructural components in vertical structures.

본 연구는 국가 제조업 경쟁력 강화를 위한 핵심 R&D 사업인 소재부품 기술개발사업을 중심으로 산학연 공동연구 네트워크의 구조적 특성을 분석하고, 각 참여 주체들의 역할과 관계를 규명하여 시사점을 제시하는 것을 목적으로 한다. 이를 위해 최근 5년간 (2020년~2024년) 수행된 소재부품기술개발사업의 공동연구 과제 565건을 대상으로 소셜 네트 워크 분석(Social Network Analysis, SNA)을 수행하였다. 분석 결과, 소재부품기술개발사업의 공동연구 네트워크는 1,262개 기관과 2,048개 협력관계로 구성된 중심-주변부 구조를 가지고 있으며, 산학연 협력(49.4%)이 가장 많은 비중을 차지하였다. 전체 네트워크에서 일부 연구 기관이 지식 공급과 확산을, 기업은 주로 지식의 흡수와 통합 역할을 수행하는 구조를 보였다. 대학은 산업계와 연구계 사이에서 지식의 흐름을 중개하는 핵심 역할을 담당하고 있는 것으로 나타났다. 협력 유형별 분석 결과, 지식의 생산, 통합, 중개 역할을 담당하는 주체가 뚜렷하게 구분되었다. 산학연 협력과 산연 협력에서는 공공 연구기관이 지식 생산 및 확산의 중심 주체로 기능하는 반면, 산학 협력에서는 대학과 대기업이 네트워크의 핵심 허브로 작용하고 있다. 산산 협력에서는 소수의 대기업 중심의 위계적 구조가 두드러졌다. 중개 역할 또한 협력 유형에 따라 상이하게 나타나, 산학연과 산학 협력에서는 대학이, 산연 협력에서는 전문 연구 기관이, 산산 협력에서는 대기업이 지식 가교로서 기능을 수행하고 있음을 확인하였다. 기술 분야별 분석 결과, 전기·전자(33.6%), 기계·소재(27.1%), 화학(20.9%) 분야가 주요 영역으로, 가장 활발한 협력이 이루어지고 있는 것으로 나타났다. 정보통신 및 지식서비스 분야는 상대 적으로 작은 규모이지만 높은 네트워크 밀도를 보였다. 기술 분야별로 주도적 역할을 담당하는 기관 유형에 차이가 나타났는데, 전통적 제조업 기반 분야(기계·소재, 화학, 전기·전자)에서는 공공 연구기관이, 융합연구 기반 분야(정보통신, 바이오·의료)에서는 기업이 지식 생산을 주도 하는 것으로 나타났다. 본 연구는 소재부품 분야 산학연 협력 네트워크의 구조적 특성을 종합 적으로 분석함으로써, 분야별 맞춤형 협력 모델 개발, 핵심 연구기관 지원 강화, 중소기업의 네트워크 참여 활성화 등의 정책적 시사점을 제시하였다.