In this study, we explored the design of improved road lighting for drivers and pedestrians using ray-tracing and reverse ray-tracing methods. Conventional road lighting often poses issues such as glare and unevenly illuminated areas, which can compromise safety and efficiency. These problems stem from traditional design approaches focused solely on achieving high luminance and electrical power. However, our research shows that higher brightness or power consumption does not necessarily equate to better road lighting. By applying ray-tracing techniques, we aimed to design a reflector that enhances visibility while being easier on the eyes of both drivers and pedestrians. Our optimized reflector design demonstrated significant improvements in both central and average illuminance levels, all while reducing energy consumption. This study suggests that careful reflector design is crucial for creating safer and more energy-efficient road lighting solutions.
In this study, we explored the design of improved road lighting for drivers and pedestrians using ray-tracing and reverse ray-tracing methods. Conventional road lighting often poses issues such as glare and unevenly illuminated areas, which can compromise safety and efficiency. These problems stem from traditional design approaches focused solely on achieving high luminance and electrical power. However, our research shows that higher brightness or power consumption does not necessarily equate to better road lighting. By applying ray-tracing techniques, we aimed to design a reflector that enhances visibility while being easier on the eyes of both drivers and pedestrians. Our optimized reflector design demonstrated significant improvements in both central and average illuminance levels, all while reducing energy consumption. This study suggests that careful reflector design is crucial for creating safer and more energy-efficient road lighting solutions.
Component-specific information is crucial for identifying sources of PM2.5 in indoor environments. However, profiles of PM2.5 at various locations, including subway tunnels are limited. This study aimed to evaluate the relationships between PM2.5 and its component across tunnels, platforms, and outdoor environments at underground subway stations in Incheon. The study was conducted at six underground subway stations in Incheon. PM2.5 concentrations were measured twice at each station, simultaneously covering the tunnel, platform, and outdoor areas. Carbon (two types), ion (eight types), and metal components (20 types) were analyzed using each analytical instruments. The mean PM2.5 concentration in the tunnel was 33.0±15.7 μg/ m3, significantly higher than the concentrations observed on the platform (12.9±4.6 μg/m3) and outdoors (13.1±7.6 μg/m3). The proportion of total metal concentrations in PM2.5 was highest in the tunnel (57.8%), followed by the platform (22.2%) and outdoor areas (11.3%). Significant correlations between the platform and tunnel were observed for organic carbon, SO4 2–, NO3 –, NH4 +, Ba, Mn, Fe, and Se. Significant correlations between the platform and outdoor were observed for SO4 2–, NO3 –, NH4 +, and Ti, while the tunnel and outdoor showed correlations for SO4 2– and NH4 +. PM2.5 concentrations and total metal concentrations were highest in the tunnel. While PM2.5 concentrations on the platform and outdoors were similar, total metal concentrations were higher on the platform than outdoors. From the platform’s perspective, the concentrations of Ba, Mn, Fe, and Se were only associated with the tunnel, while SO4 2–, NO3 –, and NH4 + had tendency of correlations between both the tunnel and outdoors. The findings suggest that for platform PM2.5 concentrations, Ba, Mn, Fe, and Se may serve as indicators of tunnel-originating PM2.5, while SO4 2–, NO3 –, and NH4 + may serve as indicators for outdoor sources.
본 연구에서는 경기도 내 유통 중인 간편조리세트 55건 내 농·축·수산물 원재료의 미생물 오염도를 조사하였다. 55 건의 간편조리세트 중 농산물이 원재료로 들어가는 제품 은 48건, 축산물이 원재료로 들어가는 제품은 43건, 수산 물이 원재료로 들어가는 제품은 16건이었다. 농·축·수산물 에서 일반세균은 100%의 검출률을 보였으며, 일반세균 평균 검출량은 농산물 6.57 log CFU/g, 축산물 4.60 log CFU/g, 수 산물 5.47 log CFU/g으로 나타났다. 농·축·수산물에서 대 장균군은 각각 81.25%, 69.77%, 43.75%의 검출률을 보였 고, 대장균군 평균 검출량은 농산물 2.83 log CFU/g, 축산 물 1.34 log CFU/g, 수산물 1.12 log CFU/g으로 나타났다. 대 장균은 13건(30.23%)의 축산물에서 0.70-2.36 log CFU/g 범위로 검출된 반면, 수산물에서는 1건(6.25%)만 검출되 었고, 농산물에서는 검출되지 않았다. 농·축·수산물에서 진 균은 각각 97.92%, 93.02%, 93.75%의 검출률을 보였고, 진균 평균 검출량은 농산물 3.82 log CFU/g, 축산물 2.92 log CFU/g, 수산물 2.82 log CFU/g으로 나타났다. 농·축· 수산물에서 식중독균은 각각 35.42%, 37.21%, 31.25%의 분리율을 보였고, 바실루스 세레우스, 살모넬라균 등 7종 의 45개 식중독균을 분리하였다. 간편조리세트로 인한 식 중독 사고 예방을 위하여 세척, 충분한 가열 섭취 및 조 리과정 중 교차오염에 대한 주의가 필요하다.
This study was performed to investigate antioxidant and anti-inflammatory activities of perilla(Perilla frutescens L.) seed, flower and leaf according to extraction condition. Perilla seed extracts(PSE), perilla flower extracts(PFE), perilla leaf extracts(PLE) was extracted by stirring extraction (STE, 25°C), shaking extraction (SHE, 80°C), and sonication assisted extraction(SAE, , 25°C) with 94% ethanol, 60% ethanol and distilled water, followed by analysis of total polyphenol and flavonoid and testing radical scavenging activities. The highest total polyphenol content (5.47, 9.36, 38.58 mg gallic acid equivalent/g), total flavonoid content(5.77, 8.62, 46.44 mg catechin equivalent/g), ABTS(10.68, 19.46, 63.56 mg trolox equivalent/g) and DPPH(6.51, 7.69, 79.73 mg trolox equivalent/g) radical scavenging activity of PSE, PFE and PLE was observed in the HWE with 60% ethanol,. Among the three extraction method, SHE provided the best results for yield, polyphenol, flavonoid content of perilla seed, flower, leaf in comparison to STE or SAE. SHE with 60% ethanol of perilla seed, flower, leaf more effectively inhibited secretion of nitric oxide(NO) and pro-inflammatory cytokine in RAW 264.7 macrophage exposed to LPS compared to other extraction solvent and method. Therefore, these extracts obtained from perilla seed, flower, leaf could be used antioxidant and anti-inflammatory ingredients in the food industry.
This study investigates the integration of astronomy-related topics in the Korean national science curricula spanning from 1945 to 2023. We analyze the placement and extent of astronomy content across different school levels. Astronomy contents in the science curricula have changed in response to social needs (e.g., practical knowledge required for agriculture and fishery) and advancement in astronomical research (e.g., the discovery of exoplanets and the suggestion of new cosmological parameters). Contents addressing the motions of celestial objects and stellar physical properties have remained relatively consistent. In the latest 2022 revised national curriculum, scheduled for implementation in 2024, several elements, such as coordinate systems, have been removed, while the inquiry activities using digital tools are emphasized. The incorporation of the cosmic perspectives in the national curriculum, as well as astronomy education within the context of education for sustainable development, remains limited even in the most recent curriculum. For future life revisions, the active participation of researchers is needed to reflect the latest astronomical research progress and scientific characteristics in the field of astronomy.
The objective of this study was to investigate the distribution of functional compounds in perilla leaves of various genetic resources and their antioxidant activities. A comprehensive analysis of functional compounds was conducted for 90 genetic resources, focusing on total polyphenol content (TPC), total flavonoid content (TFC), individual phenolic content (IPC), and lutein. Their antioxidant activities were then analyzed based on their radical scavenging capacity using ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl). The TPC content exhibited a range of 13.19 to 35.85 mg gallic acid equivalent/g, whereas the TFC content varied from 11.74 to 46.51 mg catechin equivalent/g. Total IPC was detected in a range of 6,310.98 to 40,491.82 μg/g. Lutein was detected at levels between 70.97 and 597.97 μg/g. ABTS and DPPH radical scavenging activities of perilla leaves ranged from 30.39 to 58.58 mg trolox equivalent (TE)/g and from 7.74 to 46.56 mg TE/g, respectively. Furthermore, correlation analysis demonstrated that rosmarinic acid, a phenolic acid, exhibited a significantly positive correlation with antioxidant activity. These findings suggest that various genetic resource of perilla leaves could effectively mediate antioxidant capacity. Results of this study provide valuable information for use of perilla leaves in Korea as functional food materials.
Although monitoring of radon has been extensively implemented throughout South Korea, the risk assessment has been mainly limited to indoor environments such as schools, workplaces, and multi-use facilities, and evaluations have normally been performed separately. In this study, the differences in radon exposure according to two groups (< 1 and 1-6 years old) were evaluated considering various indoor and outdoor environments, timeactivity patterns, variations in radon concentrations, and dwelling type (single detached and apartment house) using Monte-Carlo simulation. The distribution and representative values of radon concentration by micro-environments were confirmed through the Anders-Darling test, and a uniform distribution was applied in case of uncertainty. The effective dose ranged from 1.81 ± 1.19 to 2.81 ± 3.02mSv/y. Comparing the levels recommended by EPA, WHO, and ICRP with the value of the 95th percentile of this study, it was found that the results for those dwelling in detached houses exceeded recommended levels. Infants that spend a lot of time in homes with relatively high levels of concentration of radon are assessed to be somewhat more vulnerable to radon exposure.
Endoscopic ultrasonography-guided intervention has gradually become a standard treatment for peripancreatic fluid collections (PFCs). However, it is difficult to popularize the procedure in Korea because of restrictions on insurance claims regarding the use of endoscopic accessories, as well as the lack of standardized Korean clinical practice guidelines. The Korean Society of Gastrointestinal Endoscopy (appointed a Task Force to develope medical guidelines by referring to the manual for clinical practice guidelines development prepared by the National Evidence-Based Healthcare Collaborating Agency. Previous studies on PFCs were searched, and certain studies were selected with the help of experts. Then, a set of key questions was selected, and treatment guidelines were systematically reviewed. Answers to these questions and recommendations were selected via peer review. This guideline discusses endoscopic management of PFCs and makes recommendations on indication for the procedure, pre-procedural preparations, optimal approach for drainage, procedural considerations (e.g., types of stent, advantages and disadvantages of plastic and metal stents, and accessories), adverse events of endoscopic intervention, and procedural quality issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This will be revised as necessary to address advances and changes in technology and evidence obtained in clinical practice and future studies.
본 연구는 메꽃과 6종의 식물에 대해 신속하고 비파괴적으로 분류하기 위해 근적외선 (Vis-NIR) 스펙트럼을 이용하였고 데이터의 전처리와 머신러닝 기술을 적용하였다. 전국적으로 분포하는 메꽃과 6종에 대해 야외에서 휴대용 분광기를 이용하여 판별하였다. 식물의 잎의 표면에서 400~1,075 nm의 근적외선 스펙트럼 (1.5 nm)을 수집하였 다. 수집된 스펙트럼 데이터는 3가지의 전처리와 raw데이터를 이용하였고 4종류의 머신러닝 모델을 적용하여 높은 판별 정확도를 확인하였다. 전처리와 머신러닝 모델의 조합을 통해 분석된 판별의 정확도는 43~99%의 범위로 분석되었고, standard normal variate 전처리와 support vector machine 머신러닝 모델의 조합에서 판별 정확도가 98.6% 로 가장 높게 나타났다. 본 연구에서 수집된 스펙트럼은 식물의 성장단계, 다양한 측정 지역 및 잎에서의 측정 위치 등과 같은 요인과 더불어 데이터 분석을 위한 조건으로 최 적의 전처리와 머신러닝 기술을 적용한다면 메꽃과 식물의 야외에서의 정확한 분류가 가능하고 이들 식물의 효과적인 관리와 모니터링에 활용할 수 있을 것으로 판단되었다.
큰느타리의 수출시 유통 기한 연장을 목적으로 수확시 품질 등급, 대와 자실체 사이를 잘라낸 손질 처리 유무, 그리고 관행 OPP 봉지에 끈묶음한 포장 방법을 개선시켜 트레이용기에 넣은 후 밀봉처리시 효과를 구명하고자 하였다. 수확시 품질 등급은 수확전 재배사의 온도를 9~11˚C 낮추어 적응시킨 버섯을 특품으로, 관행 13~15˚C로 적응시킨 버섯을 상품으로 설정하였다. 선별한 특품과 상품 버섯을 이용하여 손질 및 포장방법으로 3처리구를 두었다. 첫째는 절단 손질 후 OPP 봉지에 넣어 끈묶음한 포장(Cut & OPP), 둘째는 손질하지 않고 OPP 봉지에 넣어 끈묶음한 포장(Uncut & OPP), 마지막으로 개선포장방 법으로 절단 손질한 후 트레이용기에 넣고 밀봉한 포장 (Cut & Tray)이었다. 포장 완료한 버섯 처리구를 0℃ 저장고에 42일간 보관하면서 포장 내부의 기체 조성, 품질 요인의 변화, 신선 품질에 대한 관능평가를 실시하였다. 특품과 상품의 버섯 모두 Cut & Tray, Cut & OPP, 그리고 Uncut & OPP 처리 순으로 전반적으로 신선도가 높게 유지되었다. 특품 버섯의 유통 수명은 Cut & Tray 처리의 경우 30일, Cut & OPP 처리의 경우 28일, Uncut & OPP 처리의 경우 21일이었고, 상품 버섯의 유통 수명은 Cut & Tray 처리시 22일, Cut & OPP 처리시 17일, 그리고 Uncut & OPP 처리시 14 일이었다. 신선 버섯의 품질에 영향을 미치는 요인은 갓과 대의 갈변과 부패 지수였다. 특히, 버섯 대의 아랫부분의 갈변과 그에 연관된 표피색 a*값과 b*값의 변화가 품질 저하의 주요인이었다.
The emission of particulate matter and volatile organic compounds (VOCs) from a motor vehicle painting booth was quantitatively evaluated. Most particulate matter was emitted during the spraying process, in which the PM10 concentration was 16.5 times higher than that of the drying process. When the paint was being sprayed, the particles with a diameter of 1.0~2.5 μm accounted for 39.4% and particles greater than 2.5 μm in diameter accounted for 30.6% of total particles. On the other hand, small particles less than 0.5 μm in diameter accounted for 52.4% of total particles during the drying process. In contrast to the particulate matter, high concentrations of VOCs were emitted during both spraying and drying processes. Butyl acetate, xylene, toluene, and m-ethyltoluene were the most abundant VOCs emitted from the motor vehicle painting booth. Additionally, xylene, butyl acetate, toluene, and 1,2,3-trimethylbenzene were the dominant ozone precursors. Especially, xylene exhibited the highest ozone production contribution (32.5~44.4%) among 34 species of the ozone precursors. The information obtained in this study can be used to establish a suitable management strategy for air pollutants from motor vehicle painting booths.
This study aimed to investigate the characteristics of odor-causing substances in Yeosu national industrial complex, which is designated as an “Odor management Area,” in 2019 and the surrounding area. The sampling sites were divided into three areas: five sites within the industrial complex (Management area), one site within the borders of the complex (Boundary area), and two sites within residential areas (Affected area) affected by odors. The odor compounds were collected from March to September at dawn, daytime, and night. The analytical items were meteorological data, complex odor, legally-designated 22 odor compounds and other VOCs. Complex odor was exceeded on the limit three occasions at two sites in the management area. Ammonia, two types of sulfides, three types of aldehydes, and five VOCs were detected to be within the emission standards. Ammonia was the most frequently detected compounds. Aldehydes and sulfur compounds made a relatively high contribution to the level of odors. Therefore, aldehydes and sulfur compounds should be reduced first in order to prevent odors from occurring.
Purpose: This study compares the chest compression quality, and the willingness and confidence to perform cardiopulmonary resuscitation (CPR) before and after education between the compression only CPR (COCPR) group and the standard CPR (STCPR) group using manikins. Method: This study employs a randomized controlled trial design. A total of 219 and 214 individuals were randomly assigned to the COCPR and STCPR groups, respectively. Both groups were asked to perform CPR for 2 min before and after education. The willingness and confidence to perform CPR were surveyed through a questionnaire. Results: Before education, the STCPR group had a significantly higher mean chest compression depth and accuracy than the COCPR group for the entire 2 min. After education, the STCPR group had a significantly higher mean chest compression depth for 2 min and higher compression accuracy for late 1 min than the COCPR group. However, no significant difference in the willingness and confidence to perform CPR according to the compression method was evident. Conclusion: Repeated training is required to maintain chest compression quality. CPR education improves willingness and confidence to perform CPR.
본 연구에서는 외부형태적으로 매우 비슷한 참조기 (Larimichthys polyactis) 와 부세 (L. crocea)의 두 종 간 구분을 위해 계측형질 분석을 포함한 몇가지 기법들을 수행하였다. 총 48개의 계측형질 중 4개의 유의한 차이를 보이는 계측형질이 파악되었으며 (p<0.05) classical dimension에서는 유의한 차이를 보이는 계측형질은 없었다 (p>0.05). 오히려, 2가지의 truss dimension (Insertion of dorsal fin base - origin of pectoral fin base와 Origin of anal fin base - origin of pectoral fin base)와 2가지의 head part dimension (Most anterior extension of the head - above of eye와 Above of eye - posterior aspect of operculum)에서는 유의한 차이가 나타났다 (p<0.05). 하지만, 이러한 4가지 계측형질 중 head part dimension의 Above of eye - posterior aspect of operculum의 계측형질을 제외한 나머지 3가지 계측형질들에서 부세가 참조기에 비해 더 큰 수치를 나타내었다 (p<0.05). X-ray 분석 결과 curved vertebral column에서 부세는 45.1±2.34° 로 참조기의 38.4±1.82°에 비해 8.4% 더 큰 수치를 나타내었다 (p<0.05). 머리부위의 표피를 제거한 후의 유상돌기 는 두 종에 모두 존재하여 일반적으로 참조기에서만 유상 돌기가 존재한다고 알려진 바와는 달리, 유상돌기는 두 종을 구분하기 위한 형질로 볼 수 없었다. 본 연구 결과는 참조기와 부세에서 일부 외부 체형에 의해 명확히 구분 가능함을 시사한다.