Existing reinforced concrete building structures have seismically-deficient details on columns and beam–column joints; therefore, accurate modeling of structural behavior is required for reliable seismic performance assessment. This study aims to investigate the differences in dynamic responses resulting from modeling variations through developing four distinct numerical models. Separate models were established to simulate flexural and shear failures of columns and beam–column joints. Using these component-level models, a structural analysis model of the target building was constructed, and nonlinear time-history analyses were performed to evaluate seismic performance. Based on the simulated dynamic behavior of the target building, soft-story mechanisms were identified, and it was identified and confirmed that column behavior plays a dominant role in governing the overall structural response.
To support English speaking instruction and assessment in Korean schools, this study developed a taxonomy of English speaking tasks by analyzing the 2022 Revised English Curriculum, reviewing standardized English speaking tests, and referring to task classifications in the CEFR and ACTFL. Three modes of English speaking were identified in response to different communication contexts and purposes: imitative, interactional, and presentational. Tasks designed to elicit each mode were further classified by task type. Imitative speaking comprised two task types: ‘listen and repeat’ and ‘read aloud’. Interactional and presentational speaking each included three task types, based on the macro functions of language use: interpersonal, transactional, and evaluative/problem-solving. Each task type was further subdivided into categories and subcategories. The resulting taxonomy can be aligned with school grade levels in the curriculum by excluding tasks that exceed the relevant achievement standards and by adjusting topics, vocabulary, language forms, and task complexity according to students’ grade levels.
하수처리장 전력 사용량의 50∼65%를 사용하는 송풍기 사용 동력 절감은 Scope 2 탄소발생을 감소시킨다. 일반적으로 국내 하수처리장은 설계기준인 일 최대 유입하수량과 유입 수질 유입 시 방류수 배출기준을 만족하도록 설계된 운전 방법으로 상시 가동하는데, 일반적인 특성을 가진 하수를 처리하는 경우 이에 맞춘 운전을 하면 송풍 동력을 절감할 수 있다. 본 연구에서는, 시뮬레이션을 통해 일반적인 하수를 처리하는 경우 4개로 구분된 호기조 중 3개만 폭기하고, 말단 호기조의 용존산소 농도와 암모니아성 질소 농도를 기준으로 전체 호기조 공급 송풍량을 조절하면 폭기 에너지를 절약할 수 있는 것으로 파악되었다. 말단 호기조 용존산소 농도를 1.5 ㎎/L로 상시 유지하고, 시간 최대 암모니아성 질소 농도를 상시 4.0 ㎎/L 이하로 유지시키는 다단 제어시스템을 도입하면 전체적으로 설계운전에 비해 16.2%의 송풍량이 절감이 될 수 있는 것으로 시뮬레이션을 통해 파악되었다. 또한 16.2% 의 송풍량 절감은 0.00599 kg CO2.eq./m3, 연간 102.7 ton의 Scope 2 탄소 발생을 절감하는 것으로 나타나, 다단제어를 포함한 Digital Twin을 실 처리장에 적용하면 송풍량 최적화를 통한 탄소발생 저감이 수행될 수 있는 것으로 나타났다.
This study proposes a methodology for predicting properties such as the density of polymer composites, including asphalt binders, and evaluates its feasibility by identifying the quantitative relationship between the structure and properties of individual polymers. To this end, this study investigates the variations in molecular dynamics (MD) results with molecular structural complexity and assesses the independence and correlation of variables that influence density. In this study, MD simulations were performed on hydrocarbon-based and individual asphalt binder molecules. The effects of various temperatures, molecular conditions, and structural features on the density were analyzed. MD-related variables influencing the calculated density were evaluated and compared with experimentally measured densities. The MD-calculated densities were used as target variables in a subsequent study, in which a machine learning model was applied to perform quantitative structure–property relationship analysis.The MD-calculated densities showed a strong correlation with experimental measurements, achieving a coefficient of determination of R2 > 0.95. Potential energy exhibited a tendency to cluster into 4–6 groups depending on the molecular structure. In addition, increasing molecular weight and decreasing temperature led to higher density and viscosity. Torsional energy and other individual energy components were identified as significant factors influencing both potential energy and density. This study provided foundational data for the property prediction of asphalt binders by quantitatively analyzing the relationship between the molecular structure and properties using MD simulations. Key features that could be used in the construction of polymer structure databases and AI-based material design were also proposed. In particular, the integration of MD-based simulation and machine learning was confirmed to be a practical alternative for predicting the properties of complex polymer composite systems.
본 연구는 중부지역에서 사료작물인 수단그라스 교잡종(Sorghum x Sudangrass hybrid, SX-17)의 기후 영향에 대한 취약성을 평가하고 생산성에 영향을 미치는 주요 기후 요인을 규명하고자 2017년부터 2018년까지 충청북도 충주와 충청남도 청양에서 현장 실험을 수행하였으며, 기후 취약성은 농촌진흥청에서 정의한 지수를 활용하여 평가하고 기온 및 강수량 자료는 기상청에서 제공받았다. 2018년의 수단그라스 교잡종의 생초 및 건물 수량은 고온과 가뭄 스트레스로 인해 2017년에 비해 현저히 감소하였고, 두 지역 모두 2010년 이후 기후 취약성 증가 추세를 보였으며 2018년에 최대값인 0.7에 도달하였고, 이러한 결과는 극한 기상 현상이 사료작물 생산성에 부정적인 영향을 미친다는 점을 부각시 키며 기후영향 취약성 평가는 기후변화 시나리오 하에서 효과적인 농업 적응 전략 수립을 위한 기초자료로 활용될 수 있음을 시사한다.
This study analyzed and presented zooplankton species occurrence, diversity distribution, and community composition in ninety lakes across South Korea using samples collected through the “Survey of Lake Aquatic Ecosystem Status and Health Assessment.” When comparing our results with the National Species Checklist, we identified factors within each of the three taxa that warrant improvement due to their influence on diversity assessments. To bridge the gap between the ongoing lake ecosystem surveys and the continually updated National Species Checklist-and to enhance the accuracy of diversity evaluations-we conclude that (1) greater taxonomic rigor must be reflected in the national checklist, and (2) the limitations of morphology-based identification (α-taxonomy) must be addressed. Because the National Species Checklist does not distinguish among species, subspecies, and morphospecies, it can give rise to taxonomic oversplitting and taxonomic inflation, leading to ambiguous diversity-index results. Moreover, the low resolution of morphological identification for zooplankton (at the genus, family, or class level) can introduce errors when comparing communities across habitats or detecting non-native introductions. Although alternatives such as environmental DNA and functional diversity exist, they require further refinement before being adopted in policy; therefore, they should be implemented alongside and in comparison with current aquatic ecosystem health assessment methods.
This study quantitatively assessed the impacts of climate change and extreme weather events on the suitability zones and dry matter yield (DMY) of Italian ryegrass (Lolium multiflorum Lam.) in Korea. Baseline climate (2006–2015) and recent climate (2021–2023) conditions were compared using national meteorological and crop yield data. A significant decrease in total annual precipitation (−84.3 mm, p<0.001) was observed, while winter minimum temperatures showed a slight but statistically insignificant increase (+0.27°C, p = 0.111). Suitability zone classification based on agro-climatic zoning indicated regional shifts, particularly a decrease in the best suitable zones in 2021 and partial recovery by 2023. Dry matter yield increased by 31.6% in central Korea due to improved winter survival under warmer conditions, while southern Korea experienced a 9.4% yield reduction in response to a severe spring drought in 2022. Pearson correlation analysis showed a moderate positive but non-significant relationship between precipitation and yield (r = 0.518, p = 0.292), and multiple linear regression explained 97.9% of yield variation (R² = 0.979). Precipitation had a stronger explanatory effect than temperature, suggesting that water availability is a more critical factor for forage productivity. These findings provide scientific evidence of regional climate sensitivity and support future data-driven cultivation planning.
This integrative review examined 38 published articles on the topic of formative assessment conducted in South Korean EFL settings, from 2014 to 2023. Despite strong interests in using quality formative assessments that are aimed at improving English learners’ performance, no prior systematic analyses have been performed to date. To that end, this study draws on Wiliam and Thompson’s (2008) conception of the formative assessment five-strategy model, and Yan and Pastore’s (2022) Teacher Formative Assessment Practice Scale (TFAPS), as a guiding framework to examine the extent to which formative assessment research conducted in South Korean EFL classroom settings has enacted the five key strategies and thereby promoted learning and improved teaching. For all five key strategies, more studies showcased weak evidence of implementing each strategy, and that positive student learning was more likely to be seen in studies that fully, or nearly fully, implemented the key strategies. Recommendations for enhancing formative assessment teaching and research practice are provided at the end.
본 연구는 저관리형 거리화단 화훼경관용 초화류 식물 선발을 위하여, 4종의 초본화훼식물(Zinnia elegans, Salvia splendens, Catharanthus roseus, Gomphrena globose )을 대상으로 무관 수 처리에 따른 내건성을 구명하고자 실시하였다. 4종 식물의 영구위조점을 알아본 결과, 무관수 후 백일초가 23일째 가장 먼저 고사하였고, 그 다음으로 살비아는 29일째, 일일초는 51일 째, 천일홍은 61일째에 고사하였다. 무관수 처리에 따른 4종의 용적수분함량 변화를 비교한 결과, 용적수분함량은 무관수 이후 지속적으로 감소하였고, 용적수분함량이 0%에 도달한 것은 백 일초가 무관수 16일째로 가장 빨랐으며, 그 다음으로 살비아 25일, 일일초 35일, 천일홍 40일 순으로 나타났다. 4종의 지상 부생체중의 감소율을 영구위조점에서 보았을 때 4종의 식물중 백일초의 감소율이 가장 높았고, 그 다음은 살비아, 천일홍, 일일초 순으로 높게 나타났다. 또한 지상부와 지하부 건물중의 증가율은 일일초가 가장 높았으며 통계적으로 유의하였다. 무관 수 처리에 따른 광합성 형광 변수 중 하나인 Fv/Fm 측정 결과, 백일초는 일시위조점인 15일째부터 감소하였고, 살비아는 무관 수 29일째, 일일초는 37일째, 천일홍은 43일째부터 감소하였 으며, 통계적으로 유의하였다. 무관수 처리에 따른 4종의 각 개체별 측정된 식생지수의 변화를 알아본 결과, 정규식생지수 (normalized difference vegetation index, NDVI), 광화학 반사율 지수(photochemical reflectance index, PRI), 안토 시아닌 반사율 지수(anthocyanin Reflectance Index, ARI) 가 무관수 기간동안 백일초, 살비아보다 일일초, 천일홍이 장기 간 건강한 잎의 범위에 속하였다. 본 연구결과를 종합해 볼 때, 저관리형 거리화단 화훼경관용 식물 선정 시 거리화단의 수분관 리 측면을 고려한다면 무관수 처리 후 약 50-60여 일간 생존하 여 내건성이 강한 것으로 나타난 일일초, 천일홍이 저관리형 거리화단 화훼경관 조성 시 적용 가능성이 매우 높은 식물로 판단되었다. 거리화단 화훼경관 조성 후 물관리가 어려운 거리 화단 화훼경관의 지속적인 유지, 관리에 대한 어려움이 부각되 어왔다. 따라서 저관리형 거리화단 화훼경관용 식물의 다양한 적용 및 관리를 위해서는 향후 보다 많은 식물종을 대상으로 한 실험뿐만 아니라 식물 내에서 품종 간의 비교에 대한 후속 연구도 필요한 것으로 생각되었다.
Hallucinations represent a transdiagnostic phenomenon observed in multiple neuropsychiatric disorders, including schizophrenia, substance use disorder and substance-induced psychotic conditions. Despite their clinical prevalence, objective assessment remains challenging due to its subjective nature, underscoring the critical need for validated translational models. The present study explores the biological mechanisms underlying hallucinations, evaluates the animal models developed to date, and discusses methods for analyzing these models along specific pathways. Hallucinations are primarily mediated through glutamatergic and/or serotonergic pathways. Numerous animal models for assessing hallucinations have been extensively reported; however, these models have mainly been designed to investigate specific neurotransmitter mechanisms, rather than encompassing all relevant pathways. Therefore, this study systematically examines currently established animal models based on the aforementioned neurotransmitter mechanisms and proposes future directions for developing universal animal models capable of comprehensively evaluating hallucinatory phenomena. The present study aims to provide deeper insights for future research involving animal models of hallucination.
본 연구의 목적은 소규모 대학생 집단을 대상으로 진로정체감 지위에 따른 하위집단을 분류하고, 이들 하위집단 간 희망-실천 역량의 차이를 분석하는 데 있다. 서울 소재 4년제 대학교 학부생 77명의 자료를 분석 하였다. 진로정체감 지위는 잠재프로파일분석(LPA)을 통해 성취, 유예, 미분화, 혼미의 네 개 하위집단으로 분류되었으며, 희망-실천 역량에서는 집단 간 유의미한 차이가 나타났다. 성취 집단은 대부분의 희망-실천 역 량에서 가장 높은 점수를 보였지만, 혼미 집단은 모든 영역에서 가장 낮 은 수준을 보였다. 이러한 결과를 바탕으로 진로정체감 지위에 따라 희 망-실천 이론에 근거한 차별적인 개입 방향을 제안하였다. 본 연구는 100명 이하의 소규모 집단을 대상으로 VISA를 활용한 하위집단 분류가 가능함을 확인하였으며, 진로정체감 지위별 차별적 개입 방향을 제시함 으로써 진로개입 현장에서의 실천적 연구를 촉진하고자 한다.
본 연구는 중·소규모 사업장의 높은 산업재해를 저감하기 위한 목적으로 자 기규율 예방체계의 위험성평가를 개선하는 방안을 연구하였다. 이론적 고찰을 위해 기존의 위험성평가 방법과 문제점을 파악하였고, 대기업에 비하여 열악한 중·소규모 사업장의 위험성평가수행에 어려움을 인식하였다. 이를 해결하 기 위한 수단으로 중·소규모 사업장의 지속 가능한 발전을 위해 ESG 경영 평가지표를 함께 고찰하였다. ESG 평가지표 중 산업안전 분야의 위험성평가 내용이 일부 존재하여 기존 위험성평가와 ESG 평가지표 간 관계성, GAP분석 을 통해 문제점을 발견하고 리스크마이닝 기법으로 개선방안을 제안하였다. 모든 사업장에 적용가능한 고도화된 자기규율 예방체계의 위험성평가 개선방 안으로 향후 중소규모 사업장의 산업재해를 경감시키는데 중요한 역할을 할 것으로 기대한다.
Volatile fatty acids (VFAs) are designated as offensive odor substances, and they are known for their strong polarity and adsorptive properties, which can lead to significant losses during sample collection and analysis. This study evaluates two analytical methods currently outlined in the odor process test standards, alongside an analytical system utilizing adsorption tubes and another system that uses ion chromatography (IC). Furthermore, suitable analytical methods were proposed for analyzing concentrations below the odor threshold and emission limits. When assessing SPME-GC/FID, SPME-GC/MSD, TD-GC/MSD, and IC based on the internal quality control standards specified in the process test standards, all methods were found to have met these criteria. The absolute injection amounts (1 atm, 25oC) satisfying the emission limits ranged from 3 to 95 ng, while those that met the odor thresholds ranged from 0.2 to 6.5 ng. Based on these criteria, analytical systems suitable for the specified concentration range and odor thresholds were identified. The results are as follows. 1. The analytical systems confirmed to be suitable for quantifying limits were TD-GC/ MS and IC. 2. In terms of recovery and precision, both TD-GC/MSD and IC were found to be suitable. 3. Regarding detection limits, both previously mentioned systems were satisfactory. 4. Finally, concerning quantitation limits, both systems were adequate; however, TD-GC/MSD slightly exceeded the odor threshold analysis range for propionic acid by approximately 1.5 ng. The odor thresholds for the four VFAs were converted to absolute quantities (1 atm, 25oC), confirming that the IC system met the following criteria: (1) calibration range and curve, (2) accuracy and precision, and (3) instrumental detection and quantitation limits.
The selection of topics to be included in the long-term program of work is a part of the working methods of the International Law Commission. A good selection of topics provides a good start to the Commission’s work and fulfills its double function of the progressive development and codification of international law. The process of selecting works for the longterm program of work now faces numerous challenges such as the appearance of new areas of international law and the increased engagement of States and international organizations in the preparation of new conventions outside the Commission’s channel. The challenges call for further improvement of criteria for the selection of works to preserve and enhance the quality of the Commission’s work. This article will briefly highlight the process of the selection of works in the Commission’s history and focus on the implementation of criteria for the selection of topics used during various times, and their advantages and limitations.
Reconstructing reliable length composition data is critical for applying length-based age-structured stock assessment models, particularly in data-limited situations. This study suggests an approach to reconstruct the length composition of small yellow croaker (Larimichthys polyactis) caught by the offshore gillnet fishery in Korean waters where existing length data often lack temporal coverage and representativeness. To address this issue, measured data by size-specific boxes were integrated with auction-based landing data. Using the number of individuals per size-specific box as a proxy, a nonparametric bootstrap resampling method was applied to generate probabilistic length composition estimates. Normality tests and ANOVA revealed non-normal and non-linear patterns in data, supporting the use of nonparametric methods and the classification of size-specific boxes. Approximately 130,000 boxes (30 million individuals), including those with partial missing data, were analyzed using an automated R-based workflow, and a hot-deck method was used for imputation. The reconstructed length compositions showed stable distributions with low standard errors, indicating improved representativeness compared to the raw data. This approach provides a practical framework for generating reliable length composition inputs to enable the application of length-based age-structured stock assessment models, particularly when age composition data are limited or poor.
곤충 Laccifer lacca의 분비물인 stick lac에서 얻어지는 락색소는 물에 용해되는 붉은색 식용 색소로, 식품에 붉 은 색을 더하는 착색제이다. 주요 성분은 안트라퀴논계 기 반의 laccaic acid로 A, B, C, D, E로 구성된다. 본 연구 의 목적은 HPLC-DAD를 활용하여 laccaic acid를 정량적 으로 분석할 수 있는 방법을 검증하는 것과 섭취 노출량 을 산출하는 것이다. 제안된 분석법은 특이성, 선형성, LOD, LOQ, 정확성, 정확도 등 다양한 검증 항목에서 평 가되었으며, 매트릭스 효과 또한 충분히 고려되었다. 모든 매트릭스에서 검량선은 높은 선형성 (R20.999)을 보였고, 락색소의 MDL과 MQL은 각각 1.93 mg/kg와 5.86 mg/ kg로 확인되었다. 일내 및 일간 회수율 시험에서 정확도 는 91.5-100.9% 사이였고, 정밀도는 0.8-2.6%RSD로 AOAC 기준을 충족하였다. 한국에서 유통되는 다양한 식 품들을 수집하여 락색소를 모니터링하여 식품 유형별 락 색소 섭취 노출량을 평가하였다. 락색소 섭취 수준의 범 위는 국민전체, 섭취자 각각 0.0000-0.0027 mg/kg·bw/day 와 0.0000 -0.0306 mg/kg·bw/day였다. 개발된 분석법은 다 양한 식품 유형에 적용 가능하여 락색소 추출물의 효과적 인 모니터링을 가능하게 하며, 섭취량 평가를 통해 락색 소의 안전성 평가에 추가적으로 활용될 수 있을 것이다.
This study investigated the impact of various soil environmental factors on the growth and yield of Actinidia arguta (A. arguta) in Suwon, South Korea. By employing Pearson correlation analysis, we explored the relationships between soil properties such as pH, electrical conductivity (EC), organic matter content, available phosphorus, available silicon, soil moisture, and soil temperature with A. arguta growth and yield. The results revealed that soil temperature and EC had the strongest positive correlations with A. arguta growth, while organic matter content exhibited a strong negative correlation with fruit yield. The high levels of available phosphorus emerged as a potential adverse factor affecting yield. These findings suggest that managing soil temperature, EC, and phosphorus levels is crucial for optimizing A. arguta productivity. Future research should focus on fine-tuning phosphorus levels and further investigating the interactions between soil factors to enhance A. arguta yield and sustainability.