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Hydrograph Separation and Flow Characteristic Analysis for Observed Rainfall Events during Flood Season in a Forested Headwater Stream (산지계류에 있어서 홍수기의 강우사상에 대한 유출수문곡선 분리 및 특성 분석)

  • Nam, Sooyoun;Chun, Kun-Woo;Lee, Jae Uk;Kang, Won Seok;Jang, Su-Jin
    • Korean Journal of Ecology and Environment
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    • v.54 no.1
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    • pp.49-60
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    • 2021
  • We examined the flow characteristics by direct runoff and base flow in a headwater stream during observed 59 rainfall events of flood season (June~September) from 2017 to 2020 yrs. Total precipitation ranged from 5.0 to 400.8 mm, total runoff ranged from 0.1 to 176.5 mm, and runoff ratio ranged from 0.1 to 242.9% during the rainfall events. From hydrograph separation, flow duration in base flow (139.3 days) was tended to be longer than direct runoff (78.3 days), while the contribution of direct runoff in total runoff (54.2%) was greater than base flow (45.8%). The total amount and peak flow of direct runoff and base flow had the highest correlation (p<0.05) with total precipitation and duration of rain among rainfall and soil moisture conditions. Dominant rainfall events for the total amount and peak flow of base flow were generated under 5.0~200.4 and 10.5~110.5 mm in total precipitation. However, when direct runoff occurred as dominant rainfall events, total amount and peak flow were increased by 267.4~400.8 and 169.0~400.8 mm in total precipitation. Therefore, the unique aspects of our study design permitted us to draw inferences about flow characteristic analysis with the contribution of base flow and/or direct runoff in the total runoff in a headwater stream. Furthermore, it will be useful for the long-term strategy of effective water management for integrated surface-groundwater in the forested headwater stream.

A Prediction of N-value Using Artificial Neural Network (인공신경망을 이용한 N치 예측)

  • Kim, Kwang Myung;Park, Hyoung June;Goo, Tae Hun;Kim, Hyung Chan
    • The Journal of Engineering Geology
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    • v.30 no.4
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    • pp.457-468
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    • 2020
  • Problems arising during pile design works for plant construction, civil and architecture work are mostly come from uncertainty of geotechnical characteristics. In particular, obtaining the N-value measured through the Standard Penetration Test (SPT) is the most important data. However, it is difficult to obtain N-value by drilling investigation throughout the all target area. There are many constraints such as licensing, time, cost, equipment access and residential complaints etc. it is impossible to obtain geotechnical characteristics through drilling investigation within a short bidding period in overseas. The geotechnical characteristics at non-drilling investigation points are usually determined by the engineer's empirical judgment, which can leads to errors in pile design and quantity calculation causing construction delay and cost increase. It would be possible to overcome this problem if N-value could be predicted at the non-drilling investigation points using limited minimum drilling investigation data. This study was conducted to predicted the N-value using an Artificial Neural Network (ANN) which one of the Artificial intelligence (AI) method. An Artificial Neural Network treats a limited amount of geotechnical characteristics as a biological logic process, providing more reliable results for input variables. The purpose of this study is to predict N-value at the non-drilling investigation points through patterns which is studied by multi-layer perceptron and error back-propagation algorithms using the minimum geotechnical data. It has been reviewed the reliability of the values that predicted by AI method compared to the measured values, and we were able to confirm the high reliability as a result. To solving geotechnical uncertainty, we will perform sensitivity analysis of input variables to increase learning effect in next steps and it may need some technical update of program. We hope that our study will be helpful to design works in the future.

A Comparison between the Reference Evapotranspiration Products for Croplands in Korea: Case Study of 2016-2019 (우리나라 농지의 기준증발산 격자자료 비교평가: 2016-2019년의 사례연구)

  • Kim, Seoyeon;Jeong, Yemin;Cho, Subin;Youn, Youjeong;Kim, Nari;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.36 no.6_1
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    • pp.1465-1483
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    • 2020
  • Evapotranspiration is a concept that includes the evaporation from soil and the transpiration from the plant leaf. It is an essential factor for monitoring water balance, drought, crop growth, and climate change. Actual evapotranspiration (AET) corresponds to the consumption of water from the land surface and the necessary amount of water for the land surface. Because the AET is derived from multiplying the crop coefficient by the reference evapotranspiration (ET0), an accurate calculation of the ET0 is required for the AET. To date, many efforts have been made for gridded ET0 to provide multiple products now. This study presents a comparison between the ET0 products such as FAO56-PM, LDAPS, PKNU-NMSC, and MODIS to find out which one is more suitable for the local-scale hydrological and agricultural applications in Korea, where the heterogeneity of the land surface is critical. In the experiment for the period between 2016 and 2019, the daily and 8-day products were compared with the in-situ observations by KMA. The analyses according to the station, year, month, and time-series showed that the PKNU-NMSC product with a successful optimization for Korea was superior to the others, yielding stable accuracy irrespective of space and time. Also, this paper showed the intrinsic characteristics of the FAO56-PM, LDAPS, and MODIS ET0 products that could be informative for other researchers.

A Study on the Evaluation of Nepal's Inclusive Business Solution: Focusing on the Application of OECD DAC Evaluation Criteria (네팔의 포용적 비즈니스 프로그램 평가에 관한 연구: 경제협력개발기구 개발원조위원회 평가기준 적용을 중심으로)

  • Kim, Yeon-Hong;Lee, Sung-Soon
    • The Journal of the Korea Contents Association
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    • v.21 no.4
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    • pp.177-192
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    • 2021
  • The Development Assistance Committee of the Organization for Economic Cooperation and Development discusses the reorganization of the five evaluation criteria of the Public Development Assistance Committee, which are used internationally, and the five evaluation criteria including adequacy, efficiency, effectiveness, impact, and sustainability when assessing public development assistance in 1991. This study is to derive alternatives by applying the evaluation criteria of the Development Assistance Committee of the Organization for Economic Cooperation and Development in the evaluation of the inclusive business program being implemented in Nepal since 2019. As a result of the study, the adequacy of Nepal's inclusive business program was consistent with continuous employment and job creation for vulnerable groups such as disabled and orphan women. Efficiency can be said to be efficient in that processes such as work order and work confirmation are made with an electronic management tool, and delivery of the result is transmitted online, saving time and cost compared to other industries. The effectiveness of this project can be said to be an effective program in that it provides high-quality jobs such as providing specialized computer graphics education for the vulnerable, such as disabled and orphan women in Nepal, and hiring graduates as employees. Sustainability is the point that KOICA's inclusive business program has enabled vulnerable groups in the existing fields of agriculture and manufacturing to engage in the computer graphics industry, and the scalability of movies, characters, education businesses, and role models in other countries.However, considering that the scale of public development assistance will continue to increase in the future, it is necessary to establish a systematic monitoring system and a recirculation system so that the project between the donor and recipient countries can continue.

Revision of Nutrition Quotient for Elderly in assessment of dietary quality and behavior (식사의 질과 식행동 평가를 위한 노인영양지수 개정 연구)

  • Lim, Young-Suk;Lee, Jung-Sug;Hwang, Ji-Yun;Kim, Ki-Nam;Hwang, Hyo-Jeong;Kwon, Sehyug;Kim, Hye-Young
    • Journal of Nutrition and Health
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    • v.55 no.1
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    • pp.155-173
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    • 2022
  • Purpose: This study was undertaken to update the Nutrition Quotient for Elderly (NQ-E), which reflects dietary quality and behavior among Korean older adults. Methods: The first 29 items of the measurable food behavior checklist were obtained from a previous NQ-E checklist, recent literature reviews, and national nutrition policies and recommendations. One-hundred subjects (50 men and 50 women) aged ≥ 65 years living in the Seoul Metropolitan Area, including Gyeonggi Province, completed a pilot survey from March to April 2021. Based on the results of the pilot study, we conducted factor analysis and frequency analysis to determine whether the items of the survey were properly organized and whether the distribution of answers for each evaluation item was properly distributed. As a result, we reduced the number of items on the food behavior checklist and used 23 items for the national survey. Nationwide, 1,000 subjects (472 men and 528 women) aged > 65 years, completed the checklist survey, which was applied using a face-to-face survey method from May to August 2021. The construct validity of the NQ-E 2021 was assessed using confirmatory factor analysis, LISREL. Results: Seventeen food behavior checklist items were selected for the final NQ-E 2021. Checklist items addressed three factors: balance (8 items), moderation (2 items), and practice (7 items). Standardized path coefficients were used as the weights of items to determine nutrition quotients. NQ-E and three-factor scores were calculated according to the weights of questionnaire items. Conclusion: The updated NQ-E 2021 produced by structural equation modelling provides a suitable tool for assessing the dietary quality and behavior of Korean older adults.

Weekly Variation of Phytoplankton Communities in the Inner Bay of Yeong-do, Busan (부산 영도 내만에서 식물플랑크톤 군집의 주간 변동 특성)

  • YANG, WONSEOK;CHOI, DONG HAN;WON, JONGSEOK;KIM, JIHOON;HYUN, MYUNG JIN;LEE, HAEUN;LEE, YEONJUNG;NOH, JAE HOON
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.26 no.4
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    • pp.356-368
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    • 2021
  • To understand the temporal variation of phytoplankton communities in a coastal area, the biomass and diversity were weekly investigated in the inner bay of Yeong-do, Busan. In the study area, chlorophyll a concentration ranged from 0.43~7.58 mg m-3 during the study, indicating the study area was in mesotrophic or eutrophic status. The fractions of chlorophyll a occupied by large phytoplankton (> 3 ㎛ diameter) exhibited an average of 80% of total chlorophyll a in this study. Among the large phytoplankton, while Bacillariophyta was the most dominant in spring and summer, Cryptophyceae prevailed in the fall and winter. On the contrary, in the picophytoplankton community less than 3 ㎛ in diameter, Mamiellophyceae was the most dominant in most seasons, Cryptophyceae was relatively high with an average of 17.7 ± 17.6% throughout the year, but seasonal variations were large. Dinophyceae rarely occupied a higher fraction up to 60.4% of the picophytoplankton community. By weekly monitoring at a coastal station for 13 months, it is suggested that phytoplankton communities in coastal waters could be changed on a short time scale. If data are steadily accumulated at the time-series monitoring site for a long time, these will provide important data for understanding the long-term dynamics of phytoplankton as well as the impact of climate and environmental changes.

A Study on Major Safety Problems and Improvement Measures of Personal Mobility (개인형 이동장치의 안전 주요 문제점 및 개선방안 연구)

  • Kang, Seung Shik;Kang, Seong Kyung
    • Journal of the Society of Disaster Information
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    • v.18 no.1
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    • pp.202-217
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    • 2022
  • Purpose: The recent increased use of Personal Mobility (PM) has been accompanied by a rise in the annual number of accidents. Accordingly, the safety requirements for PM use are being strengthened, but the laws/systems, infrastructure, and management systems remain insufficient for fostering a safe environment. Therefore, this study comprehensively searches the main problems and improvement methods through a review of previous studies that are related to PM. Then the priorities according to the importance of the improvement methods are presented through the Delphi survey. Method: The research method is mainly composed of a literature study and an expert survey (Delphi survey). Prior research and improvement cases (local governments, government departments, companies, etc.) are reviewed to derive problems and improvements, and a problem/improvement classification table is created based on keywords. Based on the classification contents, an expert survey is conducted to derive a priority improvement plan. Result: The PM-related problems were in 'non-compliance with traffic laws, lack of knowledge, inexperienced operation, and lack of safety awareness' in relation to human factors, and 'device characteristics, road-drivable space, road facilities, parking facilities' in relation to physical factors. 'Management/supervision, product management, user management, education/training' as administrative factors and legal factors are divided into 'absence/sufficiency of law, confusion/duplication, reduced effectiveness'. Improvement tasks related to this include 'PM education/public relations, parking/return, road improvement, PM registration/management, insurance, safety standards, traffic standards, PM device safety, PM supplementary facilities, enforcement/management, dedicated organization, service providers, management system, and related laws/institutional improvement', and 42 detailed tasks are derived for these 14 core tasks. The results for the importance evaluation of detailed tasks show that the tasks with a high overall average for the evaluation items of cost, time, effect, urgency, and feasibility were 'strengthening crackdown/instruction activities, education publicity/campaign, truancy PM management, and clarification of traffic rules'. Conclusion: The PM market is experiencing gradual growth based on shared services and a safe environment for PM use must be ensured along with industrial revitalization. In this respect, this study seeks out the major problems and improvement plans related to PM from a comprehensive point of view and prioritizes the necessary improvement measures. Therefore, it can serve as a basis of data for future policy establishment. In the future, in-depth data supplementation will be required for each key improvement area for practical policy application.

BVOCs Estimates Using MEGAN in South Korea: A Case Study of June in 2012 (MEGAN을 이용한 국내 BVOCs 배출량 산정: 2012년 6월 사례 연구)

  • Kim, Kyeongsu;Lee, Seung-Jae
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.24 no.1
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    • pp.48-61
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    • 2022
  • South Korea is quite vegetation rich country which has 63% forests and 16% cropland area. Massive NOx emissions from megacities, therefore, are easily combined with BVOCs emitted from the forest and cropland area, then produce high ozone concentration. BVOCs emissions have been estimated using well-known emission models, such as BEIS (Biogenic Emission Inventory System) or MEGAN (Model of Emission of Gases and Aerosol from Nature) which were developed using non-Korean emission factors. In this study, we ran MEGAN v2.1 model to estimate BVO Cs emissions in Korea. The MO DIS Land Cover and LAI (Leaf Area Index) products over Korea were used to run the MEGAN model for June 2012. Isoprene and Monoterpenes emissions from the model were inter-compared against the enclosure chamber measurements from Taehwa research forest in Korea, during June 11 and 12, 2012. For estimating emission from the enclosed chamber measurement data. The initial results show that isoprene emissions from the MEGAN model were up to 6.4 times higher than those from the enclosure chamber measurement. Monoterpenes from enclosure chamber measurement were up to 5.6 times higher than MEGAN emission. The differences between two datasets, however, were much smaller during the time of high emissions. More inter-comparison results and the possibilities of improving the MEGAN modeling performance using local measurement data over Korea will be presented and discussed.

Revision of Nutrition Quotient for Korean adults: NQ-2021 (한국 성인을 위한 영양지수 개정: NQ-2021)

  • Yook, Sung-Min;Lim, Young-Suk;Lee, Jung-Sug;Kim, Ki-Nam;Hwang, Hyo-Jeong;Kwon, Sehyug;Hwang, Ji-Yun;Kim, Hye-Young
    • Journal of Nutrition and Health
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    • v.55 no.2
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    • pp.278-295
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    • 2022
  • Purpose: This study was undertaken to revise and update the Nutrition Quotient (NQ) for Korean adults, a tool used to evaluate dietary quality and behavior. Methods: The first 31 items of the measurable food behavior checklist were adopted based on considerations of the previous NQ checklist, recent literature reviews, national nutrition policies, and recommendations. A pilot survey was conducted on 100 adults aged 19 to 64 residing in Seoul and Gyeonggi Province from March to April 2021 using a provisional 26- item checklist. Pilot survey data were analyzed using factor analysis and frequency analysis to determine whether checklist items were well organized and responses to questions were well distributed, respectively. As a result, the number of items on the food behavior checklist was reduced to 23 for the nationwide survey, which was administered to 1,000 adults (470 men and 530 women) aged 19 to 64 from May to August 2021. The construct validity of the developed NQ (NQ-2021) was assessed using confirmatory factor analysis, linear structural relations. Results: Eighteen items in 3 categories, that is, balance (8 items), moderation (6 items), and practice (4 items), were finally included in NQ-2021 food behavior checklist. 'Balance' items addressed the intake frequencies of essential foods, 'moderation' items the frequencies of unhealthy food intakes or behaviors, and 'practice' items addressed eating behaviors. Items and categories were weighted using standardized path coefficients to calculate NQ-2021 scores. Conclusion: The updated NQ-2021 appears to be suitable for easily and quickly assessing the diet qualities and behaviors of Korean adults.

Analysis and Satisfaction Survey of Summer Camp Trends of the Education Ministry of Korean Church in the 10th Age of COVID-19 : From 2020 to 2022 (코로나 19시대의 한국교회 교육부 여름 사역 동향 분석 및 만족도 조사 : 2020년부터 2022년까지)

  • Kim, Jaewoo
    • Journal of Christian Education in Korea
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    • v.71
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    • pp.277-303
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    • 2022
  • The COVID-19 Pandemic, which began in 2020, has led to many changes in the Korean church. It created a situation in which not only the change and form of worship time, but also the definition, direction, and philosophy of ministry had to be re-established. In the early days of COVID-19 Pandemic, the Korean church recognized this as a crisis, but gradually regarded these as opportunities and tried to produce positive results. The Department of Education has also undergone many changes, especially in its summer ministry, and is expected to have undergone more dramatic changes in form, location and method than in any other church event or service. However, no accurate data on this has been collected. Accordingly, Mirae with Dreams (CEO: Pastor Kim Eun-ho), a corporation established by the Oryun Church for the next generation of ministry, conducted a survey on the summer ministry of the Korean church, which has been registered as a future member with dreams every year since 2020 when the COVID-19 fan dummy began. A similar survey was conducted in 2022 following 2021, and 260 churches responded, and the results are as follows. In 2022, the summer ministry of the Ministry of Education of the Korean Church returned to the form before the COVID-19 Pandemic. Unlike 2021, when many of them were held online, more than 81 percent said they had conducted summer camps offline, and 31 percent also conducted or attended outdoor camps. In terms of the importance of roles, when online was also the main focus, parents and teachers were equally viewed or emphasized, while in this summer's survey, 90 percent of respondents said that the role of teachers in charge or department was important. Summer events were mainly summer Bible schools and retreats, but 25% of all respondents said they conducted missionary work and evangelism at home and abroad. Compared to 2021, participation in summer camps has increased in all departments, including infant and kindergarten, elementary and middle school, and especially in infant and middle school. While preparing for the summer camp, most of the respondents said that the focus was on content and topics, and the main focus was on children's accessibility compared to 2021. As a result of synthesizing the description of the reason for the respondents who could not conduct the summer camp, about 40% said they could not conduct the summer camp due to a lack of volunteers. This is more than 30% who pointed out COVID-19 as the cause, which can be seen as an urgent problem to be solved at the Korean church and denomination level. In addition, this paper also mentioned detailed changes in each question, referring to the changes in summer camps from 2020 to 2022.