기후변화로 인해 전 세계적으로 수온이 상승하는 추세이며, 그에 따른 수계 내 유기물의 농도 증가에 따라 정수 처리 과정에서의 소독부산물 생성량 역시 상승하고 있다. 이 중 총트리할로메탄(Trihalomethanes, THMs)은 발암물질로 분류되며, 먹는 물 수질 기준이 0.1 mg/L로 설정되어 있다. 소독부산물 생성량 증가와 취수원에서의 수질 문제가 지속적으로 제기됨에 따라 안정적 수돗물 공급을 위한 대책이 필요한 상황에서 본 연구는 여름철 경기도와 경상북도 지역의 수도꼭지에서 THMs 농도를 모니터링 하였다. 또한, 과거 THMs 측정 자료와 더불어 다양한 자료를 비교ㆍ분석하여 THMs 농도 변화의 원인을 파악했다. 그 결과, 조사 지역들의 THMs 생성에는 원수의 종류, 그로 인한 용존유기탄소 (Dissolved organic carbon, DOC), 클로로필-a 인자와 더불어 계절적 요인들 중 기온과 강우량이 종합적으로 기여하는 것으로 나타났다. 특히, 선형 회귀분석을 통해 용존유기탄소와 THMs간의 상관관계가 높으며 수돗물의 용존유기탄소 농도가 2.7 mg/L 이상일 경우 THMs 농도가 법정 먹는 물 수질 기준을 초과할 가능성이 높다는 결과를 도출하였다. 이를 통해 여름철 강우가 집중되는 시기와 갈수기 THMs 관리를 위해 원수의 유기물 농도를 관리하는 노력이 필수적임을 확인하였다. 해당 결과는 정수장에서의 유기물 농도 관리를 통해 THMs 생성을 억제하는 것이 매우 중요함을 시사하며, 앞으로 먹는 물 수질 기준과 정수장 운영 관리에 용존유기탄소 수질 항목을 추가하는 방안의 검토가 필요하다 판단된다.
Fishways, particularly installed at the estuary, have a purpose to encourage fluent migration for migratory fishes, as well as amphidromous and even freshwater species. Not choosing the laborious traditional method of using traps, we assessed the efficiency of the two fishways installed at the west and east barrage of the Nakdong River estuarine barrage respectively, by analyzing the videos recorded through automatic monitoring system. We randomly selected 30 videos monthly at each fishways and identified what kind of fishes were using the fishways and categorised their behaviour such as size, time and whether they passed the monitoring system or not. As a result, a total 8 families 14 species were recorded by monitoring system, with the most dominance of Erythroculter erythropterus (Relative Abundance: 59.5%), followed by Micropterus salmoides (R.A: 19.9%) and Mugil cephalus (R.A: 9.9%). The monitoring system can capture passing fishes during night but the number of appearances of fish species at each hour of a day indicated significant diurnal activities (p<0.05). When fishes pass the monitoring system, approximately 70% of them passed through the monitoring device, while 17% of them showed fallback movement. Our finding indicates that species-specific characteristics of each fish are well represented through video monitoring method. In order to maximise advantages of using video monitoring, it is necessary to consider the installation point properly so that the monitoring system does not interfere with the movement of fish. Also, the utilisation of AI technology in the future is also necessary.
본 연구는 기업 디지털 트랜스포메이션(digital transformation) 교육의 효과성 분석을 위하여, K사 디 지털 트랜스포메이션 교육에 참여한 수료자 679명을 대상으로 2023년 11월 20일부터 11월 30일까지 설문 을 실시하였다. 설문은 학습자들의 나이, 직급 등 일반적인 특성을 포함하여, 개인특성으로 자기효능감, 학습 민첩성, 데이터 리터러시, 교육과정 특성으로 교육 만족도, 내용 이해도, 강사 전문성, 업무 관련성, 조직풍토 특성으로 전이기회, 상사지원, 그리고 현업적용도, 직무몰입, 직무성과에 대한 질문을 포함한 다. 주요 연구결과는 다음과 같다. 첫째, 일반적 특성에 따른 현업적용도 평균 차이 분석결과, 성별, 연령대, 직급, 수강영역에 따른 차이가 존재하지 않았지만, 디지털 트랜스포메이션 교육 참여 횟수, 교육 전/후 학습모임 참여 경험, 교육 전 파이썬 프로그램 활용 경험 수준에 따른 평균 차이가 통계적으로 유의미한 것으로 나타났다. 둘째, 개인특성, 교육과정 특성, 조직풍토가 현업적용도에 미치는 영향을 확인하기 위해 위계적 회귀분석을 실시한 결과, 개인특성 중에서는 자기효능감, 교육과정 특성에서는 내용 이해도, 조직 풍토에서는 전이 기회가 통계적으로 유의한 정적 영향을 미쳤으며, 영향력의 크기는 내용 이해도, 전이 기회, 자기효능감 순으로 큰 것으로 나타났다. 셋째, 현업적용도와 직무몰입, 직무성과와의 관계를 분석한 결과, 현업적용도는 직무몰입과 직무성과에 정적인 영향을 미치는 것으로 나타났으며, 현업적용도와 직무 성과와의 관계를 직무몰입이 완전 매개하는 것을 확인하였다. 이는 디지털 트랜스포메이션 교육 프로그 램에 참가한 학습자가 교육 내용에 대한 충분한 이해를 바탕으로 이를 현업에 적용하고, 직무에 몰입함으 로써 직무성과로 이어질 수 있다는 것을 의미한다. 넷째, 하위변인을 반영한 최적 모형 도출 결과, 개인특 성인 자기효능감은 교육과정 특성의 내용이해도와 조직풍토의 전이기회를 매개로 현업적용 노력과 실제 현업적용에 영향을 미쳤다. 특히, 현업적용 노력에는 내용이해도가 더 큰 영향을 미치고, 실제 현업적용에 는 전이기회가 더 큰 영향을 미친 것으로 나타났다. 이러한 연구결과를 바탕으로 후속연구 수행을 위한 시사점과 제도개선 방안을 제시하였다.
Endemic species are defined as taxa that naturally inhabit and grow within a specific area. Because they easily face regional extinction, continuous management is required. In this study, stable isotope analysis, length-weight relationships (LWRs), and condition factor (K) estimation were applied to oily bitterling Acheilognathus koreensis inhabiting three representative rivers including the Geum River basin, Seomjin River basin, and Tamjin River basin to compare ecological property and related biological conditions. Based on the corrected isotope value to account for difference in carbon isotope ratio (δ13C) of POM, Δδ13CA.koreensis-POM, estimated isotope niche areas of A. koreensis between Geum and Tamjin River populations were highly overlapped while those of the Seomjin River population were discriminated from other habitats, indicating differences in major diet sources among habitats. In addition, LWRs for the Seomjin River population showed a good growth with a b value of 3.155 compared to Geum and Tamjin River populations which showed relatively low growth rates of 2.888 and 2.968, respectively. Fluctuation of the K value of the A. koreensis tended to decrease with growth in the Geum River while that of the Seomjin River population exhibited the highest increasing trend. This study confirmed differences in diet resources among habitats for A. koreensis, which resulted growth and fatness variations for each population. Our results can be used as basic information for effective conservation and management strategies of A. koreensis populations.
Broccoli and cabbage are known to have antioxidant, cholesterol-lowering, and anticancer effects due to their high bioactive component levels. This study applied 70% ethanol and hydrothermal extraction to separate bioactive components from broccoli and cabbage. 30oBrix extracts were freeze-dried and then diluted in various concentrations with distilled water for analysis. Total polyphenol contents, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric ion reducing antioxidant power, and hydrogen peroxide scavenging activity were analyzed. The diverse antioxidant assays, except DPPH radical scavenging activity, showed that hydrothermal extracts had significantly higher activity than the 70% ethanol extracts (p<0.05). In this study, it suggested that hydrothermal extraction is relatively effective in producing broccoli and cabbage extracts. Moreover, hydrothermal extraction conditions could be low-cost and environmentally friendly.
This study aimed to examine the morphological characteristics and variation in main traits by comparing the growth of individuals of Ecklonia cava Kjellman (Laminariales, Phaeophyceae) under an aquaculture environment. This survey was conducted from April 2018 to November 2019 at the aquafarm in Jindo-gun, Jeollanam-do (South coast of Korea). To classify the morphology of individuals in the aquaculture farm of E. cava, we investigated fourteen morphological characteristics and calculated four ratios between the measured values. Juvenile individuals showed a simple or oblong lanceolate, and at 3-4 months, a short stipe and holdfast developed, along with a bladelet that developed into the secondary blade form. At 5-7 months, secondary blades were found to develop irregularly on the primary blade. At 8-10 months, the primary blade expanded and secondary blades elongated. At 11-12 months, the secondary blades became oblong. At 13-14 months, the thallus area expanded. At 15-16 months, tertiary blades were formed, the thallus became more complex, the stipe thickened, and the holdfast widened. At 17-18 months, secondary blades clearly developed along with lobes. At 19-20 months, tertiary blades developed and became similar to mature natural blades. In the principal component analysis (PCA), the monthly population of the first year (Q1) and that of the second year (Q2) of the cultured population were divided along PC1, which is related to secondary blade morphological characteristics and the holdfast width. Q2 and natural populations are distributed in descending order of volume in Jeju (J), East Coast (E), and South Coast (S) along PC2, which is related to primary blade and stipe morphological characteristics. The results of this study were judged to offer important criteria for the development of different varieties of E. cava.
PURPOSES : This study aims to propose drone-command standard operating procedure (SOP) guidelines and Analyze their potential application to increase the use and utility of drones in urban disaster situations. Although the effectiveness and efficiency of obtaining disaster-situation information through drones have been verified by previous studies and practical experience, a survey of actual drone usability indicated a utilization rate of only approximately 4.13%. METHODS : To provide guidance for improving drone command SOPs, prior research and relevant literature were reviewed to identify commonalities between disaster-response command and control and drone use. A sample of 73 active-duty firefighters, including incident commanders (ICs) and drone pilots, were surveyed and interviewed. The data were analyzed and categorized to establish the reasons why drones are not actively used in urban disaster-response procedures. RESULTS : The primary reasons identified for not actively utilizing drones in urban disaster areas were the lack of a drone command and control system and the lack of clear criteria for when to use drones in disaster situations. In addition, many problems were found in drone-operation procedures, including emergency flight approval, securing takeoff and landing sites, and accident burden due to urban flight obstacles. To address the issues identified, standards were proposed for the type, size, and scope of urban disasters requiring drone response; for accident-prevention on basic missions and through flight safety procedures; and for installing a video transmission and reception system to easily share drone video information with ICs. CONCLUSIONS : Application of the drone-command SOP guidelines to actual urban disaster situations by disaster type will help to improve the efficiency of information acquisition and flight safety. This is expected to enable increased drone utilization. In future, extension of the research reported in this paper beyond the Seoul metropolitan area via additional follow-up studies has the potential to establish applicability of the proposed SOP guidelines to a wide variety of environments and organizational characteristics.