This study aims to evaluate traffic safety facilities in school zones in Busan Metropolitan City through Importance-Performance Analysis. This study investigated the traffic safety facilities in nine school zones, which have relatively more traffic accidents in Busan Metropolitan City from 2020 to 2022, through a field study and an Analytic Hierarchy Process(AHP). It identified their performance(i.e., compliance rate) and importance to derive measures for the improvement of traffic safety facilities in school zones. The field study showed that the compliance rate of starting points among traffic safety signs was low, and no speed limits were complied with the installation regulations among traffic road markings, but road safety facilities were generally well managed and operated. As a result of AHP, the order of importance was road safety facilities, traffic safety signs, and traffic road markings. More specifically, speed bumps, safety signs, and crosswalks were found to be more important than others in road safety facilities, traffic safety signs, and traffic road markings, respectively. Importance- Performance(compliance) Analysis revealed that the traffic safety facilities necessary to be most urgently improved are starting points. This result can be resorted to underlying measures to determine priorities for installing and operating traffic safety facilities in school zones.
Reinforced concrete (RC) columns exhibit cyclic damage, such as strength degradation, under cyclic lateral loading, such as earthquakes. Considering the cyclic damage, the nonlinear load-deformation response of RC columns can be simulated using a lumped plasticity model. Based on an experimental database, this study calibrates lumped plasticity model parameters for 371 rectangular and 290 circular RC columns. The model parameters for adequate flexural rigidity, plastic rotation capacity, post-capping rotation capacity, moment strength, and cyclic strength degradation parameter are adjusted to match each experimentally observed load-deformation response. We have developed predictive equations that accurately relate the model parameters to the design characteristics of RC columns through regression analyses, providing a reliable tool for engineers and researchers. To demonstrate their application, the proposed and existing models numerically simulate the earthquake response of a bridge pier in a metropolitan railway bridge. The pier is subjected to several ground motions, increasing intensity until collapse occurs. The proposed lumped plasticity model showed about 41% less vulnerable to collapse.
Microalgae are efficient fatty acid producers owing to their high photosynthetic activities. They can act as sources of biofuel, feed, and various bioactive compounds. This study aimed to determine optimal culture conditions, including culture medium, temperature, and light intensity, to enhance the biomass and fatty acid content of the indigenous freshwater microalga, Tetradesmus obliquus. Evaluation using a high-throughput photobioreactor revealed that the optimal culture temperature and light intensity were 25°C and 300 μmol m-2 s-1, respectively. Additionally, we optimized components (N, P, and Mg) of the BG-11 medium to enhance the microalgal biomass. Modified BG-11 medium increased the T. obliquus biomass by 37% compared to the standard BG-11 medium. Subsequently, the culture medium was replaced with N- and P-depleted media to determine the abiotic stress factor that could increase the cellular fatty acid content. Notably, fatty acid content was significantly increased from 8.5% up to 14.6% on day 7 of culture in N-deficient (N-P+ and N-P-) media. Sequential optimization effectively increased the biomass by 83% and fatty acid content by >76% in T. obliquus. Our optimization method can be used to enhance the biomass and fatty acid contents of various other microalgae.
This study investigated benthic macroinvertebrates and fish in the Yeongsangang River weir and analyzed stomach contents of Squalidus chankaensis tsuchigae. Length distribution of individuals varied by site, with 91.3% and 72.7% falling within the 70-90 mm range in SC-U (upstream location of Seungchon weir) and SJ (location between Seungchon and Juksan weirs), respectively, and 77.5% within 70-80 mm and 100 mm range in JS-D (downstream location of Juksan weir). Chironomidae spp. (nonred type) were the most abundant food sources, comprising 46.3%, 76.9%, and 88.3% of the diet at SC-U, SJ, and JS-D, respectively. The Electivity Index (EI) indicated a strong preference for Chironomidae spp. (non-red type) (0.927) and avoidance for the red type (-0.929) and Limnodrilus gotoi (-0.995). The proportion of burrowers (BU) increased downstream, while swimmers (SW) decreased. The condition factor (K) varied by site, decreasing in SC-U and increasing in SJ and JS-D, showing a significant positive influence on the number of food sources (p<0.05). Among food sources, Chironomidae spp. and Baetidae sp. were predicted to be utilized across a broad range of lengths and weights, with strong connectivity observed among Tanypodinae sp., Hymenoptera sp., and Baetiella tuberculata.
Cool-season grasses are currently widely used in South Korea, but their productivity and quality may decline due to global warming associated with climate change. Warm-season grasses have shown greater adaptability to heat stress and drought conditions, making them potential alternatives for summer pasture establishment in central and southern Korea. This study aimed to compare the growth characteristics, productivity, and forage value of warm-season grasses bermudagrass and crabgrass for pasture establishment in the central region of South Korea. The experiment was conducted from May 2023 to October 2024 at the National Institute of Animal Science, Cheonan, South Korea. Crabgrass exhibited superior initial establishment and faster growth rates, whereas bermudagrass had poor initial growth, placing it at a competitive disadvantage against weeds. However, after the first cutting, bermudagrass successfully established itself and maintained a stable botanical composition. The annual dry matter productivity of crabgrass (8,586 kg/ha in 2023 and 12,013 kg/ha in 2024) was 32.62% and 40.18% higher, respectively, than that of bermudagrass (5,785 kg/ha in 2023 and 8,570 kg/ha in 2024). In forage value, crabgrass tended to show higher feed value at the initial harvest, while bermudagrass showed higher quality at the later harvests. In conclusion, these results suggest that both crabgrass and bermudagrass have potential for pasture establishment, with carbgrass being more suitable for short-term due to its rapid growth and high productivity, and bermudagrass being more appropriate for long-term due to its stable productivity in regions where overwintering in possible.
This paper aims to quantify the retrofit effect of the Bolt Prefabricated Concrete-Filled Tube reinforcement method on non-seismic school reinforced concrete building through static cyclic loading experiments. To achieve the objective, two-story specimens including a non-retrofitted frame(NRF) and a Bolt Prefabricated Concrete-Filled Tube Reinforcement Frame(BCRF) were tested under static cyclic loading, and the lateral resistant capacities were compared in terms of maximum strength, initial stiffness, effective stiffness, and total energy dissipation. In addition, the load-displacement curves were compared to the story drift limit specified in Seismic Performance Evaluation and Retrofit Manual for School Facilities to investigate if the retrofitted frame was satisfied in target performance(life safety). Experimental results showed that BCRF successfully met the target performance, with a 200% increase in maximum strength and a 300% increase in energy dissipation capacity. Additionally, both initial stiffness and effective stiffness improved by more than 30% compared to NRF. Furthermore, BCRF exhibited an effect that delayed the occurrence of bond failure.
Wood ear mushroom (Auricularia heimuer) is one of the most popular mushrooms in Korea. Bacteria in the air can act as contaminants of mushroom media, mushroom pathogens, and sources of food poisoning in the indoor environment of mushroom cultivation houses. Therefore, cultivation houses require proper management to maintain mushroom production, quality and hygiene. This study was conducted to evaluate the properties of airborne bacterial species isolated from wood ear mushroom cultivation. Nine species of indoor-airborne bacteria were tested against wood ear mushroom cultivars using confrontation assay on PDA. Among 9 species, Bacillus subtilis DUCC18238 showed the strongest inhibition effect on the mycelial growth of nine wood ear mushroom cultivars and the inhibition rate for 7 of them was more than 30%. In addition, B. subtilis DUCC18238 inhibited the mycelial growth of 11 out of 18 wild mushroom species, 7 out of 8 phytopathogenic fungi, and 5 out of 5 Trichoderma species, respectively. The results of this study show that the management of airborne bacteria in the indoor environment of wood ear mushroom cultivation houses is necessary.
This study was analyze the causes of mortality to be used as basic data to fine ways to reduced the mortality rate of stocked Holstein calves. This study was used on 917 Holstein calves stocked at a fattening farm. Of the 917 stocked calves, the head of mortality was the 33 and a calf mortality rate was 3.6 %. A results of investigating the caused of mortality by disease, respiratory disease was 17 heads (51.52%), digestive disease was 12 heads (36.36%), other diseases was 3 heads (9.09%), and accidental death was 1 head (3.03%), major caused of calf mortality was resporatory and digestive disease acoounted for 87.9% of all. A head of mortality was 30 (90.91%) when the number of transports until stocking 2 times over compared with 1 time. Season has a significant effect on calf mortality, with calves in winter experiencing the highest (13 heads, 39.39%) mortality compared to other seasons. Comparing mortality rates based on stocking age, the highest (13 heads, 39.39%) mortality rate was observed in calves stocked at under 90 days of age, compared to other age groups. Comparing mortality rates based on the feeding age, the highest (18 heads, 54.54%) mortality rate was observed in calves fed for under 60 days, compared to those fed for over 60 days and other feeding age groups.
Objectives: This study aimed to evaluate the environmental awareness and health impact of respiratory diseases among residents in the exposure area (Banwoldong) and the control area. Additionally, it sought to identify the correlation between environmental factors in the exposure area and their effects on health. Methods: This study utilized a 2021 survey of 20 residents to assess environmental awareness using a 5-point Likert scale. The measurement of indoor particulate matter (PM10, PM2.5), temperature, and humidity was conducted using a direct-reading laser light scattering device, the DT-9881M (SANE Cal. Co., Ltd., Korea). Additionally, a cohort analysis was conducted using National Health Insurance Service (NHIS) data (2002~2022) to evaluate the onset of chronic disease, focusing on residency and diagnostic records. Results: In the environmental awareness assessment, women showed a statistically significantly higher level of awareness than men regarding water pollution (p=0.0039) and soil pollution (p=0.007). Also, the incidence of respiratory diseases and asthma was statistically significantly higher in the exposure area than in the control area (p<0.0001). Conclusion: This study found significantly higher rates of respiratory diseases in the exposure area compared to the control area. Long-term exposure (≥5 years) to environmental factors in the exposure area was found to be associated with a greater health impact. This suggests a strong link between environmental factors and respiratory diseases. The results emphasize the need for region-specific environmental policies to address pollution-related health disparities.
Near infrared reflectance spectroscopy (NIRS) is widely used to assess the nutrient composition of forages. In forage, the leaf to stem ratio of alfalfa greatly affects its forage quality, with a high ratio of leaf indicated as high quality. This study aimed to evaluate the predictability of the alfalfa leaf-to-stem ratio and feed value using NIRS. Alfalfa hay was manually separated into leaves and stems by hand and the analysis samples were then made in the controlled range between 0 and 100%. Calibration models (n=320) were developed using modified partial least squares regression (MPLS) based on cross-validation. The optimal calibrations were selected based on the highest coefficients of determination in cross-validation (R2) and the lowest standard error of cross-validation (SECV). The prediction accuracy for the leaf-to-stem ratio (SECV, 5.95 vs. 5.71%; R2, 0.91 vs. 0.91) in alfalfa hay was comparable. For leaves, the standard error of calibration (SEC) was 4.94% (R2=0.94), and for stems, it was 4.81% (R2=0.94). The leaves and stems of the SEC were 4.94% (R2=0.94) and 4.81% (R2=0.94), respectively. The prediction accuracy for feed value, based on the leaf-to-stem ratio, predicted SECV values of 0.92% (R2=0.88) for crude protein (CP) content, 1.92% (R2=0.91) for neutral detergent fiber (NDF) content, 1.36% (R2=0.91) for total digestibility nutrient (TDN) content, and 9.86 (R2=0.81) for relative feed value (RFV). The results of this study demonstrate the potential of the NIRS method as a reliable tool for predicting the leaf-to-stem ratio of alfalfa hay, and show available techniques for routine feed value evaluation.
해상풍력 프로젝트의 발전사업허가 취득 및 연간 예상발전량 평가를 위해서는 최소 1년 이상의 해상관측자료 확보가 필수적 이나, 입지선정 과정 및 사전예비타당성 단계에서는 재해석자료나 중규모 모델링 자료와 같은 기상·기후데이터가 활용된다. 하지만, 이 들은 관측값 대비 다소 높은 불확도를 내포하고 있기 때문에 이들을 기반으로 한 발전량 평가 결과 역시 불확실성을 가지게 된다. 이에 본 연구에서는 HeMOSU-1 해상기상탑 관측자료와 인근 격자점에서의 ERA5, EMD-WRF 데이터의 시계열 및 특성을 비교, 검증하여 국내 서남해권의 해상풍력 프로젝트의 사전예비타당성평가의 신뢰성을 확보하고자 하였다. 본 연구에서는 기계적·열적 대기안정도 지수인 연직윈드시어와 모닌 오브코프 길이, 리차드슨 수를 각각 활용하여 관측값 부재시 국내 서남해상에서 ERA5와 EMD-WRF를 사용하는 것이 정량적으로 어느 정도의 오차를 보이는지, 또 대기안정도별 변화 트렌드는 유사한지를 파악하였다.
오늘날 도로의 이동수단은 자율주행자동차와 더불어 전동 킥보드, 전기 자전거 등과 같은 개인형 이동수단의 등장으로 인해 기존 도 로가 수용해야 할 범위는 더욱 광범위해졌으며, 개인형 이동장치의 시장 확대 및 공유서비스로 인한 개인형 이동장치의 교통사고는 급격하게 증가하고 있는 추세이다. 기존 자동차 중심의 설계 및 운영되고 있는 현재의 도로에서는 자동차 이외의 다른 교통수단 이용 자들은 인프라 시설과 서비스 면에서 안전하지 못하고 편리하지 못한 환경으로 인해 잦은 교통사고 발생과 대중교통 이용 기피 등의 문제로 이어지고 있다. 따라서, 현재 도로의 차량 중심 설계에 의한 한계가 드러나고 있으며 이에 대한 해결책으로 모든 도로 교통수 단 및 이용자가 고려되는 완전도로(Complete Streets)에 관한 관심이 증가함에 따라 완전도로 구축에 관한 정책이 필요한 실정이다. 이 에 본 연구에서는 완전도로 구축을 위해 미시적 교통 시뮬레이션 VISSIM을 활용하여 자율주행자동차 레벨 4 수준의 혼입에 따른 교 통흐름 변화를 분석하여 완전도로 구축을 위한 잉여차로 확보 가능성을 검증하는 분석을 진행하였다. 또한, 잉여차로를 활용하여 완전 도로를 구축하기 위해 국외 완전도로 디자인 매뉴얼을 참고하여 국내 도로의 적용이 가능한 평자지표를 안전성, 형평성, 쾌적성을 고려한 요인을 설정하였으며, 계층화 분석법(Analytic Hierarchy Process, 이하 AHP)을 통해 평가요인별 중요도 가중치를 산정하여 완전도로 구축을 위한 완전도로 서비스수준 산정방안을 제 시하였다. 완전도로 구축을 위한 모바일매핑시스템(MMS) 및 인공지능, 드론(UAV)을 활용하여 도로의 현황 모니터링을 진행하였으며, 도출된 평가지표와 가중치를 활용하여 대상 구간에 적용 및 비교를 위해 완전도로 개념과 가깝게 적용된 세종시의 한누리대로와 비교 ㆍ분석하였다. 이를 토대로 완전도로 서비스수준 적용을 통해 도출된 도로의 한계점을 보완한 완전도로 구축방안을 제시하고자 한다.
본 연구는 맹종죽(Phyllostachys edulis) 부산물의 고부가가치 활용을 위한 기초연구로, 맹종죽림 조사 및 소각처리를 통한 죽회 생산 기술을 개발하고자 하였다. 맹종죽림 현장에서의 죽간 벌채 후 남은 상층 부산물(잎, 잔가지, 끝대)과 수년간 방치된 하층 부산물의 바이오매스 총량을 파악한 결과, 입죽 상태의 맹종죽을 벌채할 경우, 활용될 죽간의 중량비는 56.6%, 죽림 내에 방치되는 상층 부산물의 중량비는 43.3%로 나타났다. 방치됐던 하층 부산물은 ha당 약 26톤이 잔존해 있었다. 한편, 부산물을 죽회로 활용하기 위해 소형 소각로 및 대형 무연소각로를 이용한 소각처리를 수행하였다. 현장에 설치된 소각로에서의 조사 결과, 소형소각로(화실, 57.2 ㎥)는 1시간에 10 kg, 1일 최대 80 kg을 소각하는 반면, 대형 무연소각로 (화실, 791.4 ㎥)는 1시간에 70 kg, 1일 최대 560 kg을 소각하여 약 7배의 효율을 보였다. 2차 회화 과정을 통해 얻은 순수 죽회의 수율은 약 84%였으며, 칼륨(80,000 ppm↑), 칼슘(50,000 ppm↑), 인(20,000 ppm↑), 마그네슘(20,000 ppm↑), 망간(10,000 ppm↑), 철(10,000 ppm↑) 등 다양한 무기원소가 함유되어 있었다. 본 연구는 대나무 벌채 현장에서 수행된 실험을 바탕으로, 맹종죽림의 지속 가능한 경영과 새로운 부산물 활용 방안에 대한 제시로 큰 의의가 있을 것으로 판단된다.
본 연구는 성인 발달장애인 35명과 일반 대학생 35명을 대상으로 텍 스트 단서 유형에 따른 등장인물의 감정추론 능력에 대하여 알아보고자 하였다. 연구 결과는 다음과 같다. 첫째, 두 집단 간 등장인물의 감정추 론 전체 점수에서 유의한 차이가 나타났다(p<.01). 둘째, 두 집단 간 텍 스트 단서 유형의 하위 항목별 등장인물의 감정추론 능력을 살펴본 결과 유의한 차이가 나타났다. 특히, 하위항목 중 ‘등장인물의 진술’에서 가장 큰 차이를 보였다. 또한, 텍스트 단서 유형의 하위 항목 중 '감정적인 어 휘' 과제에서 비유 표현이 포함된 문항에서 많은 오류가 나타났으며, ‘텍 스트 특성’에서 가장 낮은 평균이 나타났다. 따라서 성인 발달장애인은 텍스트 단서 유형에 따른 등장인물의 감정추론 능력에서 어려움을 겪고 있으며 단서 유형에 따라 감정추론 능력이 상이함을 확인할 수 있었다.
담관 협착 및 확장은 그 원인을 정확히 알기 어려운 경우가 많다. 호산구성 담관염은 담관 협착 및 확장을 일으킬 수 있는 양성 질환으로, 발생빈도는 드문 것으로 알려져 있다. 조직병리학, 방사선 사진, 내시경 및 혈액학적 소견을 종합하여 진단할 수 있으며, 스테로이드 투여를 통해 호전을 기대할 수 있다. 드물지만 담관 협착 및 확장의 감별진단 시 고려해야 하는 질환으로, 이 증례를 통해 호산구성 담관염을 알아보고자 한다.
아토피 피부염은 만성 염증을 동반한 알레르기성 질환 이며, 일반적으로 Type 2 염증 반응과 관련이 깊다고 알 려져 있다. Corchorus olitorius (C. olitorius)의 아토피 피 부염 치료 효과를 확인하기 위하여 2,4-dinitrochlorbenzene 로 아토피 피부염 모델을 유도한 BALB/c 마우스를 대상 으로 피부 염증 개선도를 육안으로 확인하였으며, 질환 관 련 IgE와 사이토카인(IL-4, IFN-γ and TNF-α)의 수준을 측정 하였다. 7일간의 투여기간동안 양성대조약물인 Dexamethasone 투여군의 체중은 감소하였던 반면에 모든 C. olitorius 투 여군의 체중은 꾸준히 증가하였다. 이와 같은 결과는 C. olitorius이 동물에 위해한 영향이 없었다는 것을 의미한다. C. olitorius 200 mg/kg/day 투여군의 치료 효과가 가장 뛰 어났으며, 모든 C. olitorius 투여군의 염증 관련 면역글로 불린과 사이토카인의 수준은 감소하였다. 따라서, C. olitorius 는 아토피 치료제로 충분히 활용될 수 있다고 판단된다.
경상분지 동남부인 부산 기장군에 분포하는 이천리층은 퇴적시기와 층서 대비가 이루어지지 않은 백악기 퇴적 층으로 최근 방산충 화석을 포함하는 쳐트역이 보고되어 기원지에 대한 관심이 높은 지역이다. 이번 연구에서는 이천리 층의 퇴적시기와 기원지를 규명하고, 후기 백악기 경상분지의 고지리에 대한 정보를 얻기 위해 이천리층 사암 내 쇄설 성 저어콘을 이용해 U -Pb 연대를 분석하였다. 이천리층은 선캄브리아시대에서 중생대 백악기에 이르는 넓은 연령 분포 를 보이며, 백악기, 페름기, 고원생대 연령이 우세하다. 약 95 Ma의 최소 가중평균연령을 통해 이천리층의 최대 퇴적시 기는 후기 백악기 초 세노마눔절(Cenomanian)로 제한된다. 외래기원의 방산충 함유 쳐트역과 함께 한반도 내 인접 지역에서는 분포하지 않는 중기 페름기 저어콘의 높은 함량은 이천리층의 퇴적 동안 남서 일본 지역으로부터 퇴적물이 유입되었음을 시사한다. 연대 분포를 비교한 결과, 이천리층의 주된 퇴적물 공급지는 영남육괴와 미노-탐바 쥐라기 복 합체(Mino-Tamba Jurassic accretionary complex)로 해석되며 퇴적물 공급 과정에서 페름기 연령을 가지는 암체 (Maizuru Belt)와의 혼합이 중기 페름기 저어콘의 높은 산출량에 기여한 것으로 판단된다. 다차원척도법 (multidimensional scaling)을 이용한 통계적 유사도 분석 결과도 이와 같은 해석을 뒷받침한다.
국내 유통 중인 과·채류음료 64건을 대상으로 비타민 C, 폴리페놀, 무기질 함량에 대해 분석하였다. 분석 결과 비 타민 C는 1.851-251.108 mg/100 mL의 범위를 나타냈고, 비 가열 처리 사과주스에서 평균 함량 89.646 mg/100 mL로 가장 높게 나타났다. 폴리페놀은 260.767-1895.095 mg GAE/L의 범위를 나타냈으며 비가열 처리 사과주스에서 평균 함량이 1042.311 mg GAE/L로 가장 높게 나타났다. 무기질의 경우에는 100 mL 당 평균 함량이 가열 처리 오 렌지주스에서 셀레늄, 구리가 각각 0.101 μg, 22.875 μg으 로 가장 높게 나타났다. 비가열 처리 딸기주스에서 마그 네슘, 인, 철의 평균 함량이 각각 4.281 mg/100 mL, 16.085 mg/100 mL, 0.400 mg/100 mL으로 가장 높게 나타 났으며, 가열 처리 딸기주스에서 아연의 평균함량이 149.344 μg/100 mL으로 가장 높게 나타났다. 성인남성기준 일일권장섭취량과 비교해보았을 때, 200 mL의 주스 한 컵 을 마실 경우, 비타민 C는 하루 권장섭취량의 최대 5배 섭 취가 가능했고, 무기질 중 철은 50% 이상 충족이 가능했다.
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.