In industry society, it is challenging to identify and prevent potential hazard factors since an industry is complex and changing variously. Particularly, as industrial accidents occur more frequently by secondary and tertiary indirect causes, rather than primary direct causes such as environmental changes or selfinduced disasters, it becomes more difficult to analyze the risk in safety management perspective. The purposes of this study are to reconsider the variable factors used in the existing Risk Priority Number (RPN) assessment method and to explore a new prioritization method for risks and disasters caused by various external environmental changes. To achieve this, various variables are considered including the currently used variables such as the occurrence frequency, the likelihood of occurrence, the severity. Among the variables, the eight key variables will be selected, and it is to take account of the relative weights between the variables.

This study evaluates how road profile and speed affect tire loads of a hydrogen tube trailer using MSC Adams/Car multibody dynamics simulation. A tractor and trailer loaded with 64 high-pressure cylinders were modeled, and four representative road profiles flat, pothole, short-wave, and long-wave were applied at 30, 60, and 80 km/h. Vertical tire load time histories were extracted for five wheel positions. Flat roads yielded stable loads matching static distribution. Potholes produced short, high-amplitude impacts (up to 120 kN at 30 km/h) with reduced peaks at higher speeds. Short-wave profiles caused severe asymmetric roll loads (67 kN at 80 km/h), while long-wave inputs generated smoother, moderate increases over longer durations. Load amplification diminished toward trailer axles due to suspension energy dissipation. The results inform structural design of tube trailers and development of speed-control or active load-mitigation strategies for autonomous hydrogen transport vehicles.

‘Ideographic’ originally referred to the expression of meaning or the transmission of thoughts and intentions. Its association with the issue of Chinese characters has undergone a complex process of discursive evolution. Western academia has sometimes used Chinese characters as a representative of ideographic writing systems to support the three-stage theory of world writing development, sometimes to support the construction of modern linguistic theories, and sometimes to support discourses on Chinese character education. After the Western concept of ‘ideographic writing’ entered China, the academic community, based on the structure and function of Chinese character symbols, developed a sub-conceptual system centered on ‘ideographic nature,’ refined the scope of discourse to adapt to different discursive contexts, and perfected the terminology system to create a distinctive conceptual framework; clarifying discursive positions, and redefining interpretive subjectivity. This process has localised the concept of ‘ideographic,’ forming a distinctive Chinese perspective on ideographic characters and research methodologies. The experience of the generation, variation, and reconstruction of the ‘ideographic’ concept provides important references for the construction of a Chinese-specific theoretical discourse in the field of writing systems.

본 연구는 전남 겨울철 생산되고 소비되는 절화장미의 외적 품질과 연관된 내적품질 분석을 위해 수행되었다. 절화장미 5품 종 ‘캐롤라인’, ‘하젤’, ‘주밀리아’, ‘핑크 셀러브레이션’, ‘빅토리 아’의 절화수명은 6.5~18.4일 수준이었다. 절화장미의 외적품 질과 수명품질간 상관성을 확인하였다. 초장은 절화수명과 양의 상관관계(r = 0.45**)를 보였던 반면, 생체중(r = -0.56**)과 줄기 직경(r = -0.54**)은 강한 음의 상관관계를 나타냈다. 화탁 의 너비와 절화수명간 유의미한 상관관계(r = 0.45**)를 확인하 였고 이는 절화장미의 꽃 형태 특성을 통해 내적품질을 예측할 수 있다는 것을 시사한다

본 연구는 프로판탈수소(PDH) 공정의 배가스내에 포함되어 있는 탄화수소(HC)를 이용하여 질 소산화물(NOx)을 저감하는 Metal Corrugated HC-SCR 촉매 개발을 목적으로 하였다. 산성도(Si/Al 비) 가 다른 제올라이트계 Chabazite 3종을 Metal Corrugated에 워시코팅하였고, 가장 우수한 NOx 저감 성 능을 나타낸 Chabazite에 구리 함량을 1.5%, 3.0%, 4.5%, 6.0%로 함침하여 촉매를 제조하였다. 제조된 촉 매의 NOx 저감 성능은 실험실 규모의 마이크로 상압반응기상에서 측정하였으며, 촉매 특성분석은 BET, XRF, ICP를 이용하여 분석하였다. 측정 결과, 산성도가 가장 낮은 A-Chabazite가 가장 높은 NOx 저감 성능을 보였고, 구리 함량이 높을수록 Total NOx 저감 성능은 증가되었지만 NO2 저감 성능은 감소되는 것으로 확인되었다. 3.0-A-CHA 촉매는 NO2가 완전 저감되었고, Total NOx 저감에도 큰 효과를 나타내 상용 PDH 공정에서 NO2를 중점적으로 저감하고자 한다면 충분히 적용 가능할 것으로 보인다.

This study investigated seasonal variations in phytoplankton community composition and physicochemical water quality across 90 lakes in South Korea surveyed 2022 to 2024, and examined their relationships with environmental factors. Over the course of four seasons, a total of 952 phytoplankton taxa were identified, with Bacillariophyta (diatoms) and Chlorophyta (green algae) accounting for 64.2% of the total species richness. Diatom species such as Aulacoseira granulata, Fragilaria crotonensis, and Cyclotella meneghiniana were frequently observed regardless of season. In terms of cell density, Cyanophyta were dominant, comprising 85.1% on average, with particularly high summer densities driven by blooms of Microcystis aeruginosa and Aphanizomenon sp. In contrast, diatoms accounted for the highest relative abundance in winter (54.1%). Canonical correspondence analysis (CCA) revealed that Cyanophyta and Chlorophyta were positively correlated with water temperature, TP, COD, and Chl-a, whereas Bacillariophyta and Cryptophyta showed negative correlations with these variables. These results indicate that phytoplankton communities in Korean lakes are highly responsive to variations in temperature and nutrient concentrations, and that summer rainfall-driven nutrient inflow plays a critical role in triggering cyanobacterial blooms. This study provides a scientific basis for understanding seasonal ecosystem dynamics in Korean lakes and offers foundational data for eutrophication management and the development of biological water quality assessment indices.

The blocked force from the electric vehicle compressor is transmitted through the mount to the body side, serving as a primary source of body vibration during air conditioner operation at idle. Accordingly, a method is required during the compressor development stage to quantitatively evaluate the blocked force and analyze its influence for each transmission path. In this study, the blocked force at the outlet of an electric compressor was measured, and a test model was constructed to predict the response of the vehicle body using the Frequency-Based Substructuring(FBS) method. The 6-DOF dynamic stiffness of the bushing up to 500 Hz, not measurable with the elastomer, was successfully obtained using the inverse substructuring(IS) method. Finally, the proposed method was validated by the close match between predicted and measured body vibrations for both conventional and low dynamic stiffness bushings.

Energy harvesting has become a crucial technology for sustainable energy solutions; in particular, the utilization of ambient water movement in hydrovoltaic generators has emerged as a promising approach. However, optimizing performance requires an understanding of structural factors affecting energy harvesting, particularly capillary effects. This study aimed to improve hydrovoltaic generator performance by adjusting internal fiber density, which influences water transport and ion mobility. Using cold isostatic pressing, cellulose acetate (CA) loading in a urethane mold was varied to optimize internal density. As CA loading increased, the fiber arrangement became denser, narrowing capillary pathways and reducing proton mobility. While open-circuit voltage (VOC) remained stable, short-circuit current (ISC) decreased with higher CA mass. The sample with a loading of 0.3 g exhibited the highest energy harvesting efficiency, achieving ISC = 107.2 μA, VOC = 0.15 V, and power (P) = 16.7 μW. This study provides insights into methods of improving hydrovoltaic generator efficiency through internal structural modifications.

A seismic intensity map, which describes ground motion distribution due to an earthquake, is crucial for disaster evaluation after the event. The ShakeMap system, developed and disseminated by the USGS, is widely used to generate intensity maps in many countries. The system utilizes a semi-variogram model to interpolate the measured intensities at seismic stations spatially. However, the default semi-variogram model embedded in ShakeMap is based on data from high seismic regions, which may not be suitable for the Korean Peninsula, categorized as a low-to-moderate seismic region. To address this discrepancy, this study aims to develop the region-specific semi-variogram model using local records and a region-specific ground motion model (GMM). To achieve this, we followed these steps: 1) collected records from significant earthquake events in South Korea, 2) calculated residuals between the observed intensities and predictions by the GMM, and 3) created semi-variogram models using weighted least squares regression to better fit short separation distances for PGA, PGV, SA0.2, and SA1.0. We compared the developed semi-variogram models with conventional models embedded in ShakeMap. Validation tests showed that the region-specific semi-variogram model reduced the mean squared error of intensity predictions by approximately 3.5% compared to the conventional model.

본 연구에서는 친환경적이고 경제적인 수용액 환경에서 금속-유기 골격체(metal-organic frameworks, MOF)인 UiO-66을 합성하는 방법을 개선하고, 합성 조건이 UiO-66의 표면적 및 결정성에 미치는 영향을 분석하였다. 합성 실험은 금 속 용액과 리간드 용액의 주입 순서 및 계면활성제(Tween 20)의 첨가 유무를 변화시키며 진행하였다. 그 결과, 리간드 용액 을 금속 용액에 주입하고 계면활성제를 사용하지 않은 경우, 표면적과 결정성이 더 높은 UiO-66을 얻을 수 있었다. SEM 및 XRD 분석 결과, 계면활성제의 첨가는 입자 크기와 결정 구조에 큰 변화를 주지 않았으나, BET 분석 결과 표면적 감소가 확 인되었다. 이는 합성 과정에서 계면활성제가 핵 형성과 결정 성장에 영향을 미칠 수 있음을 시사한다. 본 연구 결과는 수용액 기반 UiO-66 합성법의 최적화, 대규모 제조 공정 및 다양한 산업적 응용에 유용한 정보를 제공할 수 있을 것이다.