• Journal of Korea Water Resources Association
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• v.54 no.6
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• pp.395-405
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• 2021

When issuing forecasts and alerts for agricultural drought, the relevant ministries only rely on the observation data from the reservoirs managed by the Korea Rural Community Corporation, which creates gaps between the drought analysis results at the local (si/gun) governments and the droughts actually experienced by local residents. Closing these gaps requires detailed local geoinformation on reservoirs, which in turn requires the information on reservoirs managed by local governments across Korea. However, installing water level and flow measurement equipment at all of the reservoirs would not be reasonable in terms of operation and cost effectiveness, and an alternate approach is required to efficiently generate information. In light of the above, this study validates and calibrates the parameters of the TANK model for reservoir basins, divided them into groups based on the characteristics of different basins, and applies the grouped parameters to unmeasured local government reservoirs to estimate and assess inflow. The findings show that the average determinant coefficient and the NSE of the group using rice paddies and inclinations are 0.63 and 0.62, respectively, indicating better results compared with the basin area and effective storage factors (determinant coefficient: 0.49, NSE: 0.47). The findings indicate the possibility of utilizing the information regarding unmeasured reservoirs managed by local governments.

• Journal of The Korean Association For Science Education
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• v.41 no.2
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• pp.155-169
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• 2021

This study aims at exploring the features of science teaching orientation (STO) and its relationships with other PCK (pedagogical content knowledge) components. To do this, based on the definition of STO by Friedrichsen, Driel, & Abell(2011) and PCK model by Magnusson, Krajcik, & Borko(1999), we observed one experienced elementary teacher's science lessons for 21 lesson hours (10 hours of 'Motion of Objects' and 11 hours of 'Light and Lens') and carried out qualitative analyses of the data obtained from lessons observation, teacher interviews, and CoRe (content representation) responses. We analyzed the teacher's three aspects of STO (i.e. beliefs about the goals and purpose of science teaching, beliefs about the nature of science, and beliefs about science teaching and learning) which can converge into an overall STO of 'inquiry'. And these aspects of STO appear to interact differently with four PCK components (i.e. curriculum knowledge, learner knowledge, instructional knowledge, and assessment knowledge) depending on the topic of the lesson. It is hoped that this in-depth understanding of the features of STO and its relationship with other PCK components would provide useful information on how to monitor and improve STO and PCK of elementary teachers.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.904-914
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• 2020

Through the Ministry of Trade, Industry, and Energy, South Korea is trying to support the "Building Project for Liquified Natural Gas (LNG) Bunkering Ship," centered on the Korea Gas Corporation, while the Ministry of Maritime Af airs and Fisheries is pushing to construct an LNG bunkering terminal at Busan New Port. LNG bunkering ships are essential for supplying LNG fuel from the terminal to the ships, resulting in the need for safety operation procedures. Therefore, in this study, the stability of a coastal LNG bunkering ship operating from Busan New Port to the anchorage in Busan Port was assessed to investigate the need for operational procedures for coastal LNG bunkering ships. Seakeeping analysis of the LNG bunkering ship was performed for each significant wave height by combining the response amplitude operator from the ship motion analysis under the potential flow theory with the actual observed sea data for five years and Texel, Marsen, and Arsloe (TMA) spectrum suitable for the Busan coast. The results showed that the roll and horizontal acceleration were the main risks that affected the navigation seakeeping performance above a significance wave height of 2 m. The operational periods of the LNG bunkering ship ranged from 83.3% to 99.9% of the total observation period.

• Journal of the Korean GEO-environmental Society
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• v.22 no.3
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• pp.37-43
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• 2021

This study aimed to calculate the amount of change in soil carbon due to changes in land cover. Among the various soil carbon models, the InVEST Carbon Storage and Sequestration module was used. LULC is one of the leading factors affecting soil carbon. Therefore, this study compared the total amount of soil carbon due to changes in LULC in 2000 and 2010 across the Republic of Korea, and calculated the changes in each administrative district (city). Changes in LULC in Korea were mainly due to the increase in developed and dry areas and the decrease in grassland, indicating changes in soil carbon. The total amount of soil carbon changes in South Korea has been reduced by 11.48 (millions) in 10 years. The amount of soil carbon by administrative region decreased in most cities and provinces, but Jeju Island, in exception, showed an increase in soil carbon. Among the cities and provinces except Jeju Island, Seoul showed the smallest decrease, with a decrease of 0.033 (million t). On the contrary, the largest number of attempts to decrease was to Gyeongsangbuk-do, which saw a total decrease of 2.893 (million t). Jeju Island is the only soil carbon-increasing area with an increase of 0.547 (millions) and the agricultural area has increased 2.1 times in 10 years. In the case of soil carbon, the construction of ground observation data at the national unit is insufficient, and verification will need to be carried out through linked analysis using multiple models in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.296-301
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• 2021

GPR is used for non-destructive investigations, ground investigations, and underground facilities exploration at construction sites. In this study, the applicability to GPR exploration of water pipes linked to Network RTK was presented. Data on the water supply pipes in the study site were acquired using GPR, and the location and depth of buried water pipes could be measured. The accuracy was evaluated from the GNSS observation performance and showed a deviation of -0.16m ~ 0.15m. This satisfied the equipment performance of the public survey work regulation, suggesting that the exploration of water pipes using GPR is possible. Because GPR does not require grounding installation, as in conventional metal pipe detectors, it will increase the efficiency of work for underground facility exploration. Exploration using GPR can acquire the location and depth of metallic and non-metallic underground facilities, so it can be utilized in the construction of a GIS system. If a comparison of the exploration characteristics is carried out, it will be possible to present various uses of underground facility exploration using GPR.

• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.16-21
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• 2021

As the average age of national veterans has increased from 69 years old(2011) to 71 years old(since 2015) over the past five years, the overall medical service cost of veterans has increased by about 20%. The main cause of this phenomenon is 'ultra-aging', which accounts for 67% of veterans, while the proportion of health insurance patients aged 70 or older is 9%. Therefore, it is judged that the analysis of the trend of use of medical services at veterans hospitals in each region that is in charge of severe medical services of national veterans can serve as an opportunity to seek countermeasures for the severe medical system of national veterans. First of all, based on the details of major medical expenses (hospitalization, outpatient, pharmaceutical expenses) by region for the last 10 years(2010-2019), data significance was performed through a chi-square test, and the Central Veterans Hospital and Non-Central Veterans Hospital using EXCEL. 'Expected frequency' was calculated by year. By applying the CHITEST(observation frequency, expected frequency) function again, the p-value(p<0.05) was calculated, and the profit bias of each region's veterans hospital could be determined. The specific research method is for the last 10 years(2010-2019) for state-sponsored patients_outpatient treatment income, state-sponsored patients_hospitalization income, exempt patients_outpatients at the Central Veterans Hospital, Busan Veterans Hospital, Gwangju Veterans Hospital, Daegu Veterans Hospital, and Daejeon Veterans Hospital. A one-way analysis of variance was conducted to verify the significance of the difference between group averages on the status of 5 medical revenues of veterans hospitals in each of the 5 regions, including medical treatment income, reduced patients_hospitalization income, and reduced patients_medicine expenses. It was found to be significant(p<0.05) at all levels, including region and type. Finally, the bias in the profit structure of regional veterans hospitals was the highest in 2017(p=0.0004) and the lowest in 2013(p=0.0349). In addition, in the profit structure of the Veterans Hospital, the year in which the'regional' variable worked the most was 2019, and the year with the least affected was 2010. The order of the former is Jungang(=31,674,713), Busan(=12,314,614), Gwangju(=11,957,038), Daegu(=10,168,015), and Daejeon(=6,991,034), and the order of the latter is Jungang(=57,868,791), and Busan(=19,183,194). Gwangju(=17,904,712), Daegu(=15,656,034), and Daejeon(=14,377,395). In conclusion, the profit bias of veterans hospitals repeatedly raced the lowest(p=0.01986) and highest(p=0.03499) for the past five years(2010-2014) year by year, with the 'regional' variable being the most in the veterans hospital's profit structure It was identified as a major influence factor. On the other hand, for the last 5 years (2015-2019), the influence factors of the'regional' variable every year were in 2015(p=0.02015), 2016(p=0.01741), 2017(p=0.00045), and 2018(p=0.00394). in 2019(p=0.00227), a significant difference was confirmed at a very low level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.352-361
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• 2021

An underwater positioning method that can be applied to structures for underwater construction is being developed at the Korea Institute of Ocean Science and Technology. The method uses an extended Kalman filter (EKF) based on an inertial navigation system for precise and continuous position estimation. The observation matrix was configured to be variable in order to apply asynchronous measured sensor data in the correction step of the EKF. A Doppler velocity logger (DVL) can acquire signals only when attached to the bottom of an underwater structure, and it is difficult to install and recover. Therefore, a complex sensor device for underwater structure attachment was developed without a DVL in consideration of an underwater construction environment, installation location, system operation convenience, etc.. Its performance was verified through a water tank test. The results are the measured underwater position using an ultra-short baseline, the estimated position using only a position vector, and the estimated position using position/velocity vectors. The results were compared and evaluated using the circular error probability (CEP). As a result, the CEP of the USBL alone was 0.02 m, the CEP of the position estimation with only the position vector corrected was 3.76 m, and the CEP of the position estimation with the position and velocity vectors corrected was 0.06 m. Through this research, it was confirmed that stable underwater positioning can be carried out using asynchronous sensors without a DVL.

• Journal of the Korean earth science society
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• v.42 no.1
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• pp.88-101
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• 2021

The purpose of this study was to qualitatively examine the meaning of students' drawings in outdoor classes and modeling-based learning cycles. Ten students were observed in a gifted education center in Seoul. Under the theme of the Hantan River, three outdoor classes and three modeling activities were conducted. Data were collected to document all student activities during field trips and classroom modeling activities using simultaneous video and audio recording and observation notes made by the researcher and students. Please note it is unclear what this citation refers to. If it is the previous sentence it should be placed within that sentence's punctuation. Hatisaru (2020) Ddrawing typess were classified by modifying the representations in a learning context in geological field trips. We used deductive content analysis to describe the drawing characteristics, including students writing. The results suggest that students have symbolic images that consist of geologic concepts, visual images that describe topographical features, and affective images that express students' emotion domains. The characteristics were classified into explanation, generality, elaboration, evidence, coherence, and state-of-mind. The characteristics and drawing types are consecutive in the modeling-based learning cycle and reflect the students' positive attitude and cognitive scientific domain. Drawing is a useful tool for reflecting students' thoughts and opinions in both outdoor class and classroom modeling activities. This study provides implications for emphasizing the importance of drawing activities.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.33-42
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• 2022

In this study, flow patterns in the ice-harbor fishway were analyzed according to fluctuations of the upstream water level, an increase of weir interval, and the presence or absence of orifices using a three-dimensional commercial numerical model, Flow-3D. In order to prove the suitability of the numerical simulation results, the flow velocity and flow rate at the exit of the fishway were observed using a 3D ultrasonic velocimetry on an actual ice-harbor fishway installed downstream of the Daegok bridge in Gyeongan-Cheon. Four types of turbulence modules can be selected for the Flow-3D model. As a result of verification with observation data, the RNG model best described the flow characteristics in the ice-harbor fishway. The velocity structure in the fishway according to fluctuations of the upstream water level was simulated. The results showed that the plunging flow and the streaming flow were mixed at the lowest water level. When the water level increased about 10 cm or more from the lowest water level, the plunging flow disappeared in all pools and only the streaming flow occurred. Contrary to expectations, even when the water level is rose a little, the flow simply occurred mainly on the streaming flow. If the interval between the weirs is increased, both the plunging flow and the streaming flow are showed continued even if the water level rises. In addition, compared to the case where there are no orifices at the bottom of the weirs, the plunging flow tends to be generated in several pools. It is necessary to prevent blocking orifices through active management so that various flow patterns in the fishway can be generated in multiple pools.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.3
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• pp.1-18
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• 2022

Prior studies have shown positive effects of outdoor activities on the elderly's physical, mental and social health. 'Active aging' and 'age-friendly' neighborhood can be created by modifying the experiences and perceptions of the outdoor environment. This study aims to investigate the outdoor activities of the elderly living in a low-income elderly concentrated area and their perception of the neighborhood environment. We also explored the context of interactions between the facilitators and inhibitors of outdoor activities on the basis of temporal, spatial, and social conditions. We used a mixed method approach by collecting two different types of qualitative GIS data : observation maps of the main places and individual cognitive maps with in-depth interviews. The observational map analysis indicated that the preferred places and activity patterns differ by age, gender, and size of the group. The cognitive map and interviews demonstrated that the elderly's activity goals and perception of the landscape differ by places such as forests, parks, streams, open-spaces, vegetable gardens, and alleys. The elderly's desire for outdoor activities can be better fulfilled when their front doors and alleys are well-connected to an open-sight pleasant space. Familiarity is an important factor for the elderly, therefore it is important to remove the psychological and physical barriers by increasing the legibility and accessibility of places. In addition, social interactions and conflicts can have a significant influence on the elderly's occupation of space in the neighborhood environment.