The primary purpose of this study is to develop system modules of school buildings and the seismic loss function of the system modules for regional loss assessment of school buildings. System modules of school buildings were developed through statistical analysis of school facilities in Korea. The structural system of school buildings with non-seismic details is defined as reinforced concrete with partially masonry walls (RCPM), and 27 system modules of RCPM were developed considering the number of stories, spans, and the age of the building. System modules were designed to assess the structural behavior by applying the shear spring model and the shear failure of the columns of the school building. Probabilistic seismic demand models for each component of system modules were derived through nonlinear dynamic analysis to determine the relationship between seismic intensity, drift ratio, and peak floor acceleration of system modules. The seismic loss function was defined as the total damage ratio, which is the ratio of replacement cost to repair cost to evaluate the seismic loss quantitatively. The system module-based seismic loss well predicted the observed data. It will be possible to help many stakeholders make risk-informed decisions for a region through the regional loss assessment of school buildings in Korea.
This study presents a seismic fragility assessment methodology incorporating the cumulative damage effects of repeated seismic loading on structures. Conventional seismic fragility assessment methods typically focus on single earthquakes across multiple structures; however, seismic events often occur in sequences, with each event adding cumulative damage that can amplify the overall damage. Ignoring the effects of repeated earthquakes in fragility assessments may lead to underestimating seismic risk. This study proposes a simplified but efficient fragility assessment method that accounts for repeated earthquake effects using probabilistic combinations of each damage state. This procedure applied the capacity spectrum method to consider capacity degradation from displacement caused by prior earthquakes. Applying various earthquake scenarios, this study analyzes the effects of damage accumulation from earthquake occurrence sequences, structural behavior types, and seismic design levels on the fragility of structures under repeated earthquake events.
In stable continental regions, selecting appropriate ground motions for seismic design and dynamic response analysis presents significant challenges. This study evaluates the liquefaction potential of the Nakdonggang delta region, South Korea, by generating synthetic ground motion scenarios and applying a scenario-based liquefaction assessment approach. We utilized a hybrid broadband ground motion simulation method proposed by Graves and Pitarka (2010, 2015) to create bedrock ground motions for three hypothetical earthquakes (Mw 6.2 and 6.0) occurring along the Dongrae and Miryang faults. The generated synthetic ground motions were used as input for onedimensional nonlinear site response analyses, incorporating shear wave velocity profiles derived from surface wave inversion. The simulated ground motions demonstrated higher responses at short periods and relatively weaker responses at long periods compared to the Korean design spectra. This amplification of long-period components was attributed to the dynamic response of deep sedimentary layers, while high-frequency components were generally deamplified due to damping effects in shallow silty layers. Liquefaction susceptibility was assessed using surface ground motions derived from the site response analyses, following the SPT-based simplified method proposed by Idriss and Boulanger (2008). Results indicated high liquefaction potential across most sites for the Dongrae earthquake scenario, while liquefaction was unlikely for all sites under the Miryang-1 scenario. For the Miryang-2 scenario, liquefaction was predicted at some sites. Overall, liquefaction is expected at PGA values of approximately 0.13 g or higher, with sites exhibiting lower shear wave velocities being more vulnerable to liquefaction
The increase in radioactive waste increased the demand for transportation to the disposal facility. Prior to transporting radioactive waste, confirming that the potential exposure is insignificant is crucial. Overland transportation risk assessment models were developed tailored to domestic characteristics. Dose assessment using this model requires selecting appropriate factors. However, users may struggle to derive appropriate values, leading to inaccuracies. Additionally, if assessment results show outliers, prioritizing factors for review can be challenging. Therefore, sensitivity analysis is necessary to prioritize factors for accurate assessment. In this study, sensitivity analysis was conducted on the on-link public risk assessment model factors for radioactive waste overland transportation. Initially, assessment models were analyzed by each detailed exposure scenario. Subsequently, uncertainty propagation-based sensitivity analysis methodology was applied. The default values for the assessment model factors were set, and sensitivity analysis was conducted based on road type for maximum individual and collective dose assessment models. For the maximum individual dose model, the distance to the samedirection vehicle was the most sensitive, whereas for the collective dose model, vehicle velocity was the most sensitive. The results of this study can be used as the basic data on radioactive waste transportation risk assessment in Korea in the future.
This study examines the beliefs and practices regarding performance assessment among Korean English teachers in secondary schools. A survey was conducted with 109 teachers using a 52-item online questionnaire to investigate the extent to which teachers’ beliefs align with their instructional practices and to categorize them based on these criteria. Although teachers acknowledge the pedagogical advantages of performance assessment, a significant gap exists between their beliefs and actual implementation, primarily due to the considerable time required for its execution. Teachers with longer tenure and higher qualifications demonstrated a more positive and effective application of performance assessment. The findings highlight the necessity for targeted professional development to enhance teachers’ use of performance assessment strategies, especially for those who are skeptical about their effectiveness. Such initiatives are essential for bridging the gap between beliefs and practices, fostering an environment that promotes the effective use of performance assessment, and ultimately improving teaching quality and student learning outcomes in Korean English education.
본 연구는 유럽연합(European Union, EU)의 디지털 서비스법(Digital Services Act, DSA)과 브뤼셀 효과(Brussels effect)가 X(舊 Twitter) 플랫폼에 미친 영향을 데이터 분석을 통해 평가한다. DSA는 디지털 플 랫폼에 대한 규제 강화와 콘텐츠 관리의 투명성을 요구하며, X는 이를 통해 불법 콘텐츠와 혐오 발언에 대한 처리 방식을 개선하고 있다. 본 연구는 2023년부터 발행된 DSA의 투명성 보고서를 기반으로, 국가별 콘 텐츠 조정 효율성과 자동화 및 수동 검토 시스템의 성과를 분석한다. 이 를 위해, 데이터 수집 및 전처리를 거쳐 Python을 활용한 통계적 분석 을 적용하였다. 또한, 유럽 국가별로 발생한 집행 차이와 그로 인한 문제 점을 살펴보고, 글로벌 디지털 규제의 확산 가능성에 대한 정책적 시사 점을 제시한다.
Biodiversity encompasses species diversity, which includes species richness and species evenness. High species diversity is known to contribute to community stability and the potential for maintaining healthy ecosystem functioning. However, the most commonly used species diversity indices have some limitations, as they require species-specific abundance data for each community. In contrast, phylogenetic diversity measures the evolutionary distances between species within a community, reflecting ecological and/or evolutionary divergences and niche differences, without requiring abundance data. This study assessed biodiversity by calculating phylogenetic diversity indices for freshwater fishes (19 species) and aquatic insects (49 species) at three sites within Seoraksan and Odaesan National Parks. The aquatic insects studied belong to the EPT group (Ephemeroptera, Plecoptera, and Trichoptera), which are widely used as bioindicators of aquatic ecosystems. Two mitochondrial DNA genes were used as molecular markers: COI and cyt b for fish, and COI and 16S rRNA for the EPT - group. Overall, Odaesan National Park exhibited higher phylogenetic diversity in both fishes and aquatic insects compared to Seoraksan National Park, although this difference was not statistically significant. The highest phylogenetic and species diversity were observed for fish at the OD2 site (Woljeong District) and for the EPT group at the OD1 (Gyebangsan) and SA2 (Jangsudae) sites. Correlation analysis revealed that phylogenetic diversity indices were more positively associated with species richness than species diversity indices. This study serves as a pilot project for establishing standardized methods for assessing biodiversity in national park habitats using phylogenetic diversity. It also aims to inform various policies, such as the development of biodiversity assessment systems and the prioritization of protected areas within national parks.
농산물 재배, 수확 후 세척 등에 사용되는 농업용수는 미생물에 오염될 경우 병원균을 농산물로 전파하여 식중 독을 유발할 수 있기 때문에 관리가 필요하다. 이 연구는 2021년부터 2023년까지 하천수, 저수지, 지하수 등 다양 한 수원의 농업용수에서 대장균군과 대장균의 오염 수준 을 조사하고 자외선(ultraviolet, UV) 소독이 농업용수 내 미생물을 저감시키는 데 얼마나 효과적인지 평가하였다. 농업용수의 미생물 수질조사 결과 대장균 오염도는 수원 에 따라 차이가 있는 것으로 나타났다. 하천수의 대장균 농도는 평균 0.95±1.23 log CFU/100 mL였으며, 저수지는 평균 0.76±1.07 log CFU/100 mL, 지하수는 평균 0.1±0.47 log CFU/100 mL, 기타수원은 평균 0.6±0.87 log CFU/100 mL로 조사되었다. 수원별로 보면 하천수, 저수지, 지하수 순으로 높은 미생물 오염을 보였다. 다양한 용수 조건에 서 자외선 소독을 테스트한 결과, 99.9% 미생물 비활성화 에 필요한 UV 선량은 증류수에서 1.2-1.6 mW/cm2·sec, 농 업용수 원수에서 2.0-2.7 mW/cm2·sec 범위 였다. 고형물 응집제를 통해 전처리된 농업용수는 처리되지 않은 농업 용수 원수에 비해 자외선 투과율이 높았으며, 미생물을 99.9% 감소시키는 데 필요한 자외선 선량이 더 낮아지는 것으로 나타났다. 용수 자외선 투과도가 감소함에 따라 소독 효율이 감소함에도 불구하고 본 실험에서 조사된 선량 은 수질에 상관없이 수초 내 99.9%의 미생물 감소를 달 성하는 것으로 나타나, UV 소독기술은 농업용수의 미생 물 위험을 줄이는 데 효과적인 방법으로 판단된다.
식품 사기는 글로벌 식품 공급망에 상당한 위협을 가하 며 경제적 안정성과 공중 보건에 영향을 미친다. 이 리뷰 에서는 먼저 식품 사기 취약성 평가(food fraud vulnerability assessment, FFVA)를 조사하여 다양한 기관의 통합된 정 의와 분류를 통한 표준화된 방법론의 필요성이 강조되었 다. 네 가지 주요 FFVA 도구인 ‘United States Pharmacopeia (USP) 식품 사기 완화 지침’, ‘International Featured Standards (IFS) 표준 제품 사기’, ‘SSAFE 식품 사기 취약 성 평가 도구’, ‘미국 Food and Drug Administration (FDA) 와 United States Department of Agriculture (USDA) criticality, accessibility, recuperability, vulnerability, effect, and recognizability plus shock (CARVER+Shock) 도구’의 주요 특징과 한계점 등을 살펴보았다. 또한 Safe Supply of Affordable Food Everywhere (SSAFE)의 식품 사기 취 약성 평가 도구를 적용하여 우유, 향신료, 오일, 유기농 식 품, 육류, 해산물 및 알코올의 공급망에 대한 취약성 평가 사례를 살펴보았다. 그 결과, 취약성을 평가할 때 원자재 나 제품이 브랜드 또는 상표 위조에 덜 취약한 경우 평가 설문에서 위조 관련 질문을 제외하는 등 식품 공급망 특 성이나 조사 대상에 따라 평가 항목이 조정되었다. 또한 식품 사기 행위의 기술적 탐지 난이도, 기업의 윤리적 문 화, 모니터링 시스템의 구축 정도가 식품 사기 취약성에 상당한 영향을 미치는 것으로 나타났다. 현재 이러한 평 가도구들은 귀중한 프레임워크를 제공하지만, 식품 사기 의 진화하는 본질을 해결하기 위해 보다 통합적이고 적응 가능한 접근 방식이 필요하다는 점이 시사되었다. 식품 사 기 예방을 위한 강력하고 글로벌한 표준을 수립하기 위해 서는 향후 FFVA 방법론을 개선하고 산업, 규제 기관 및 학계 간의 협력이 보다 강화되어야 할 것이다.
This study was conducted in September 2023 to establish proper eating habits and enhance the nutritional knowledge of elementary school students in Daegu during a nutrition camp hosted by the Daegu Metropolitan Office of Education. A total of thirty boys and twenty-three girls participated, with an average age of 11.2 years. The breakfast skipping rate was 11.3%, while 84.9% reported eating out once or twice a week, and 86.8% indicated they consumed delivery food once or twice a week. Regarding snacks, 47.5% of students reported eating snacks twice a day, and 73.6% identified as picky eaters. Furthermore, 66% of the participating students had no prior experience with nutrition education or consulting nutritionists. The students' nutritional knowledge score before the start of the nutrition camp was 14.4 out of 20, and after the end of the nutrition camp, it statistically increased significantly to 16.4 points (p<0.001). The level of nutritional knowledge of students who participated in the nutrition camp improved significantly compared to before the start of the nutrition camp, and this result shows that various activity programs including nutrition education and nutrition counseling can be effective.
In this study, we developed a technology that can measure key evaluation items in the field for various rehabilitation methods and evaluated its performance. The results are as follows. First, when the spray-on lining adhesion strength is measured after drying at high temperature (60℃) for 4 hours and cooling for 2 hours, the results are equivalent to or higher than the adhesion strength measured at room temperature after 48 hours. Therefore, the time required for measuring the adhesion strength in the field can be shortened to 1/8, and it is expected to be helpful in evaluating the condition of the spray-on lining. Second, depending on close or adhesive to existing pipe of the liner of the close-fit lining or CIPP lining, and the grouting condition of the slip lining, the sound frequency generation pattern, the vibration magnitude, and duration using the impact echo showed different characteristics. Therefore, it is thought that it is possible to evaluate liner lifting or grouting failure through analysis of the acoustic frequency, vibration magnitude, and duration. Third, when water penetrates the back of the liner of the close-fit lining or CIPP lining, it was found that the water penetrated between the liner and the existing pipe acts as a couplant, and a signal is repeatedly generated in which ultrasonic energy is transmitted and reflected to the steel pipe after the liner. Therefore, it is judged that it is possible to check whether water has penetrated the back of the liner using ultrasonic waves. Fourth, the liner tensile strength of the close-fit, CIPP lining was compared with the tensile test and the instrumented indentation test, and it was found that the tensile strength was similar. So it was judged that it will be helpful in evaluating the mechanical strength change without the liner specimen in the future.
This study presents an integrated indoor air quality index (IAQI) algorithm aimed at enhancing the efficiency of indoor air quality management in diverse indoor environments. The proposed IAQI accounts for the combined effects of multiple pollutants, offering a more comprehensive approach than traditional concentrationbased methods. Findings from four exposure scenarios and probabilistic health risk assessments indicate that the IAQI can be tailored to reflect occupant characteristics and space usage, thereby providing improved protection for sensitive populations, such as newborns. The application of occupant-specific criteria led to reductions in pollutant concentrations and associated health risks compared to conventional standards. Furthermore, the IAQI incorporates correction factors and weighted adjustments, facilitating robust risk assessments in complex multi-pollutant contexts. By addressing the limitations of single-pollutant management, this approach supports the development of more effective strategies for indoor air quality control. The proposed algorithm holds significant potential for practical applications in indoor air quality management and policymaking. Future research should focus on validating its effectiveness across a wider range of indoor environments.
This study was conducted to establish a range of sodium reduction acceptable to consumers through collaboration between food and nutrition experts and franchise restaurants to reduce sodium in franchise restaurants. This study was conducted sequentially in 2018 using focus group interview and in-depth interview with experts, development of low-sodium pizza. Sodium content of low-sodium pizza was then analyzed along with preference evaluation of low-sodium pizza. Results of expert interviews showed that gradual sodium reduction was desirable. Sodium-reduced pizzas were manufactured using sauces and toppings that gradually reduced refined salt and soy sauce. Results of physicochemical analysis showed that sodium contents of pizzas were reduced by 5.3%, 7.9%, and 12.7% in the experimental groups P1, P2, and P3, respectively, compared to the control group (487.43 mg/100g). As a result of evaluating the intensity of pizza taste, saltiness and greasiness were lower in sodium-reduced pizza group, while sweetness and spiciness were higher. The preference and willingness to recommend sodium-reduced pizza were the highest for pizza with a 12.7% reduction. A 7-12% reduction in sodium in currently commercially available pizzas had no effect on taste preference. It is viewed positively by consumers. Thus, such reduction can be applied at a realistic level in franchise restaurants.
The purpose of this study was to verify the radon reduction effectiveness of some radon barrier paints using the laboratory test on radon exhalation rate. The radon exhalation characteristics and radon exhalation rate of three radon barrier paints for concrete and three radon barrier paints for stone finishes were evaluated before and after application. Then the radon reduction rate was calculated to confirm the reduction effects. The results showed that the radon reduction rate of radon barrier paint was less than 10%, which is not effective in reducing radon. These findings suggest that a reliable radon reduction evaluation method is needed to utilize radon barrier paints as an indoor radon control measures.
Following the implementation of the Act on the Prevention of Light Pollution Due to Artificial Lighting in 2013, local governments designated lighting environment management zones and conducted assessments of the impacts of light pollution on the environment to ensure compliance with acceptable light emission standards. In addition, according to the Act on the Prevention of Light Pollution Due to Artificial Lighting, local governments conduct and manage light pollution assessments every three years. However, measuring and analyzing during nighttime requires a significant amount of time and labor. Therefore, this research aims to improve the current light pollution environmental impact assessment method by utilizing aerial information from satellite data and establishing a database of light pollution assessment methods, thereby laying the foundation for light pollution management. In this study, a reference light source was installed on the ground, and the luminance measurements of the installed reference light source and the advertising light sources on-site were analyzed to derive brightness values for ground light sources using the optical band (R, G, B) values from aerial information derived from satellite images. The analysis produced predictive equations for light pollution from upward lighting and general advertising lighting. When these equations were applied to residential and commercial areas in the lighting environment management area, the results indicated that the predicted rooftop upward lighting prediction brightness exceeded the acceptable standard of light emission of 800 cd/m2 in residential areas, and the advertisement lighting prediction brightness exceeded the standard of 1,000 cd/m2 in commercial areas.
This study conducted an acute toxicity assessment using Daphnia magna to evaluate the potential for increased toxicity when pharmaceuticals persist in aquatic environments not as single substances but in mixed forms. In single-substance toxicity tests, the antibiotics clarithromycin and sulfamethoxazole showed EC50 values of 22.3 mg L-1 and 61.05 mg L-1, respectively. However, the EC50 for the mixture of the two substances was determined to be 31.1 mg L-1. Based on these findings, applying the Similar Mode of Action (MOA) equation from the QSAR Toolbox, as recommended by OECD non-testing methods, produced an estimated EC50 of 33.7 mg L-1 for the mixture, showing a difference of 8.5% compared to the experimental value. This study confirms that combined exposure to pharmaceuticals can increase toxicity due to synergistic effects, indicating a significant potential risk to aquatic ecosystems. According to the UN-GHS classification criteria, clarithromycin, sulfamethoxazole, and their mixture were all classified as Category 3, indicating potential toxicity to aquatic organisms. These results emphasize the importance of toxicity assessments that consider interactions between multiple contaminants in real environmental settings, contributing to the development of effective toxicity evaluation and management strategies for the protection of aquatic ecosystems.
수전해 시스템에서 제어되지 않은 수소 크로스오버(hydrogen crossover)는 효율 저하 및 폭발 위험성 등을 야기시 키는 위험 요인이다. 수전해 공정에서 양이온교환막(cation exchange membrane, CEM)은 완전히 수화된 상태로 운전되기 때 문에 이중상(two-phase) 물질로 취급하는 것이 중요하다. 본 총설에서는 수소 크로스오버의 특성 평가 중 발생할 수 있는 주 요 기술적 문제를 요약하였다. 특히, pressure decay method (PDM)는 수소 크로스오버를 정확하게 측정하기 위한 기법으로 평가되며, 막 내부 구조 분석에도 활용할 수 있다. 또한, 수소 크로스오버를 평가하는 데 있어 permeability (즉, 고유 물질 특 성) 차원의 고유한 한계를 논의하고, 공정 안전성을 위해 flux 기반(즉, 공정 파라미터)으로의 전환 필요성을 강조한다. 추가 적으로, 막-촉매 계면에서의 과포화(supersaturation) 현상이 크로스오버에 미치는 영향에 대한 연구 필요성을 강조한다.
탄소 섬유 강화 플라스틱(CFRP) 복합재는 높은 인장 강도, 강성, 내식성 및 경량 특성으로 인해 콘크리트 부재의 내부 보강 재로 점점 더 선호되고 있다. 그러나 많은 구조물들이 수명 동안 부식성 환경에 노출되어 CFRP 복합재의 내구성을 저해할 수 있다. 본 연구에서는 ASTM D7705 표준의 가속 시험 프로토콜에 따라 CFRP 그리드를 60°C의 알칼리 및 산성 용액에 침지하여 가혹한 환 경에 노출시켰다. 실험은 인장 시험, 무게 변화 분석. 및 주사 전자 현미경(SEM)을 포함하여 재료의 열화를 평가하였다. 실험 결과, CFRP 그리드는 알칼리 환경보다 산성 환경에서 더 우수한 저항성을 나타냈다. 알칼리 환경에서는 수지 열화의 영향을 크게 받았으나, 산성 환경에서는 180일 동안 약 1.58%의 인장 강도 감소만을 보였다.
This study determined the minimum size of a representative molecular structure for use in future dynamic analyses of asphalt binders. The minimum representative size, considering factors such as aging, additive types, and temperature variations, was established using density and radial distribution functions. This approach ensures that the structure reflects temperature-dependent property changes, which are critical characteristics of asphalt binders. In this study, the structure of asphalt-binder molecules was generated using the composition proposed by Li and Greenfield (2014) for AAA1. To assess the appropriateness of the molecular structure size, we generated additional structures, X2 and X3, maintaining the same composition as X1, but with two and three times the number of molecules, respectively, as suggested by Li and Greenfield (2014). Silica and lignin were considered as additives, and the aging conditions examined included unaged, short-term aging, and long-term aging. In addition, 11 temperature conditions were investigated. The density and radial distribution functions were plotted and analyzed. The variables influencing the density and radial distribution functions were set as the aging degree of the asphalt binder (unaged, short-term aging, long-term aging), 11 temperature conditions ranging from 233 to 433 K in 20 K intervals, structure size (X1, X2, and X3), and the presence of additives (no additives, silica, and lignin). For density, clear differences were observed based on the degree of aging, temperature conditions, and presence of additives, whereas the structure size did not significantly affect the density. In terms of radial distribution functions, the X1 structure reflected differences based on the degree of aging and the presence of additives but was limited in exhibiting temperature-dependent variations. In contrast, the X3 structure effectively captured temperature-dependent trends, indicating that the size of the molecular structure is crucial when evaluating energy calculations or physical tensile strength, necessitating careful assessment.
The fishing industry is globally recognized as a high-risk sector with substantial safety challenges. This study analyzes Norway's fishing vessel safety management legislation and risk management practices. The goal is to derive insights that can enhance South Korea's safety management for fishing vessels. Norway has established a culture of safety through regular inspections, mandatory safety training, the implementation of safety management systems, and active involvement of fishermen in risk assessments. These measures have significantly reduced maritime accidents. This study suggests incorporating effective elements of Norway’s safety management into the South Korean context, emphasizing a participatory approach that actively involves fishers.