• Journal of the Korean earth science society
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• v.41 no.6
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• pp.557-574
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• 2020

The purpose of this study is to analyze the cause of high PM2.5 mass concentrations in Cheongju for the period of non-Asian dust days using the weather chart, the stream lines at 850 hPa, the backward trajectory, and the weather and air quality model. As a result of analyzing the time series of PM2.5 concentrations and weather charts for the episodic days in Cheongju, the weather patterns were shown in related to long-range transport of PM2.5 from China or surrounding areas. In fact, in the PM2.5 time series, 60-80 ㎍ m-3, which is more than 2-3 times higher than the concentration attributed to Cheongju activities, was observed as a background concentration related to long-range transport. The distribution of high PM2.5 concentration was typically dependent on the locations of the high and low pressures above the ground while the upper jet stream passed through the Korean Peninsula. Consequently, the high PM2.5 concentration in Cheongju is due to massive air pollutants in the form of smog originated from industrial, household and energy combustion sources of Beijing and other nearby regions of China. These air pollutants move along a fast zonal wind caused by the atmospheric pressure arrangement. high concentration of PM2.5 in Cheongju City is because the mass of air pollutants in the form of smog generated from industrial, household and energy combustion origins in Beijing or other nearby regions of China move along a fast wind speed zone according to the atmospheric pressure arrangement of long-distance transportation. Air pollutants including PM2.5 show an M-shaped pattern that passes through the topography of the Cheongju basin from north to south as a belt or band-shaped pollutant. The ground high pressure according to the above-ground high pressure expansion area and cut-off low or low pressure arrangement, or the bands in the form of river stems appear in a gradual incremental pattern that changes into a U-shape under the influence of the wind.

• 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.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.1
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• pp.74-80
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• 2022

The vegetation of historical sites has been a form of vegetation that has remained since some years ago, but in modern times, vegetation and terrain have been deformed or damaged due to urban development, which was followed by an industrialization. As a solution to this, it is necessary to establish a plan for restoration and management by referring to the vegetation and landscape remaining in the historic site as indicators. This study was conducted to provide basic data for vegetation and landscape management of Baekje Historic Sites in Seoul by comparing and analyzing location characteristics, existing vegetation, and remaining vegetation of past substitutional vegetation for Pungnaptoseong and Mongchontoseong, Baekje Historic Sites in Seoul. As a result of the study, Pungnaptoseong and Mongchontoseong are located near the main stream of the Han River, Pungnaptoseong is located on a flat land consisting of natural embankments and floodplains, and Mongchontoseong is located on a hilly area. In the case of existing vegetation, it has been confirmed that Pungnaptoseong mainly has ornamental trees planting sites, while Mongchontoseong has a distribution of residual species from the past that grow in villages and hilly lowlands. The Substitutional vegetation of Pungnaptoseong and Mongchontoseong was synthesized based on the location characteristics and actual vegetation, it is estimated that the hilly areas may have been divided into "Quercus aliena Blume.", "Quercus mongolica Fisch. ex Ledeb." and so on, "Pinus densiflora Siebold & Zucc." on dry land,"Salix koreensis Andersson.", "Juglans mandshurica Maxim.", "Alnus japonica (Thunb.) Steud." in rivers and tributaries, "Quercus acutissima Carruth." in the main part of the forest, "Pinus densiflora Siebold & Zucc.", "Salix koreensis Andersson.", "Zelkova serrata (Thunb.) Makino." as a divine tree in the beginning of the village. Since the 1960s, all substitutional vegetation in the past has disappeared due to the introduction of foreign species and the creation of urban areas in Pungnaptoseong and Mongchontoseong, and the landscape has also been damaged. Fortunately, the substitutional vegetation was estimated in consideration of the species of residual trees distributed along the walls, climate, location characteristics, and times, but this study was conducted based on literature and existing vegetation surveys. Therefore, it is necessary to supplement the past target vegetation in Baekje historical sites in Seoul through quantitative experiments such as plant relic analysis in the future.

• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1607-1622
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• 2022

The purpose of this study is to determine the actual performance of cool roof in preventing absorbed solar radiation. The spatial correlation between surface temperature and absorbed solar radiation is the method by which the performance of a cool roof can be understood and evaluated. The research area of this study is the vicinity of Jangyu Mugye-dong, Gimhae-si, Gyeongsangnam-do, where an actual cool roof is applied. FLIR Vue Pro R thermal infrared sensor, Micasense Red-Edge multi-spectral sensor and DJI H20T visible spectral sensor was used for aerial photography, with attached to the drone DJI Matrice 300 RTK. To perform the spatial correlation analysis, thermal infrared orthomosaics, absorbed solar radiation distribution maps were constructed, and land cover features of roof were extracted based on the drone aerial photographs. The temporal scope of this research ranged over 9 points of time at intervals of about 1 hour and 30 minutes from 7:15 to 19:15 on July 27, 2021. The correlation coefficient values of 0.550 for the normal roof and 0.387 for the cool roof were obtained on a daily average basis. However, at 11:30 and 13:00, when the Solar altitude was high on the date of analysis, the difference in correlation coefficient values between the normal roof and the cool roof was 0.022, 0.024, showing similar correlations. In other time series, the values of the correlation coefficient of the normal roof are about 0.1 higher than that of the cool roof. This study assessed and evaluated the potential of an actual cool roof to prevent solar radiation heating a rooftop through correlation comparison with a normal roof, which serves as a control group, by using high-resolution drone images. The results of this research can be used as reference data when local governments or communities seek to adopt strategies to eliminate the phenomenon of urban heat islands.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.627-646
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• 2022

Recently, the seriousness of climate change-related problems caused by global warming is growing, and the average temperature is also rising. As a result, it is affecting the environment in which various temperature-sensitive creatures and creatures live, and changes in the ecosystem are also being detected. Seasons are one of the important factors influencing the types, distribution, and growth characteristics of creatures living in the area. Among the most popular and easily recognized plant seasonal phenomena among the indicators of the climate change impact evaluation, the blooming day of flower and the peak day of autumn leaves were modeled. The types of plants used in the modeling were forsythia and cherry trees, which can be seen as representative plants of spring, and maple and ginkgo, which can be seen as representative plants of autumn. Weather data used to perform modeling were temperature, precipitation, and solar radiation observed through the ASOS Observatory of the Korea Meteorological Administration. As satellite data, MODIS NDVI was used for modeling, and it has a correlation coefficient of about -0.2 for the flowering date and 0.3 for the autumn leaves peak date. As the model used, the model was established using multiple regression models, which are linear models, and Random Forest, which are nonlinear models. In addition, the predicted values estimated by each model were expressed as isopleth maps using spatial interpolation techniques to express the trend of plant seasonal changes from 2003 to 2020. It is believed that using NDVI with high spatio-temporal resolution in the future will increase the accuracy of plant phenology modeling.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.1-9
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• 2022

The effect of sediments in a waste dumping area on marine organisms was evaluated using sediment toxicity tests with a benthic amphipod (Monocorophium acherusicum) and bioluminescent bacterium (Vibrio fischeri) in accordance with the Korean Standard Method for Marine Wastes (KSMMW). Nine sites in the East Sea-Byeong, East Sea-Jeong, and Yellow Sea-Byeong areas were sampled from 2016 to 2019. The test results showed that the relative average survival rate (benthic amphipods) and relative luminescence inhibition rate (luminescent bacteria) were below 30%, which were judged to be "non-toxic." However, in the t-test, a total of 12 benthic amphipod samples (6, 1, 1, and 4 in 2016, 2017, 2018, and 2019, respectively) were significantly different (p<0.05) from the control samples. To identify the source of toxicity on benthic amphipods, a simple linear regression analysis was performed between the levels of eight heavy metals (Cr, As, Ni, Cd, Cu, Pb, Zn, and Hg) in sediments and the relative average survival rate. The results indicated that Cr had the highest contribution to the toxicity of benthic amphipods (p = 0.000, R2 = 0.355). In addition, Cr was detected at the highest concentration at the DB-85 station and exceeded the Marine Environment Standards every year. Although the sediments were determined as "not toxic" according to the ecotoxicity criteria of the KSMMW, the results of the statistical significance tests and toxicity identification evaluation indicated that the toxic effect was not acceptable. Therefore, revising the criteria for determining the toxic effect by deriving a reference value through quantitative risk assessment using species sensitivity distribution curves is necessary in the future.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1041-1052
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• 2022

This study is to estimate the optimal ecological flow and analysis the spatial distribution of fish habitat for Andong dam downstream reach (4,565.7 km²) using PHABSIM (Physical Habiat Simulation System) and River2D. To establish habitat models, the cross-section informations and hydraulic input data were collected uisng the Nakdong river basic plan report. The establishment range of PHABSIM was set up about 410.0 m from Gudam streamflow gauging station (GD) and about 6.0 km including GD for River2D. To select representative fish species and construct HSI (Habitat Suitability Index), the fish survey was performed at Pungji bridge where showed well the physical characteristics of target stream located downstream of GD. As a result of the fish survey, Zacco platypus was showed highly relative abundance resulting in selecting as the representative fish species, and HSI was constructed using physical habitat characteristics of the Zacco platypus. The optimal range of HSI was 0.3~0.5 m/s at the velocity suitability index, 0.4~0.6 m at the depth suitability index, and the substrate was sand to fine gravel. As a result of estimating the optimal ecological flow by applying HSI to PHABSIM, the optimal ecological flow for target stream was 20.0 m³/sec. As a result of analysis two-dimensional spatial analysis of fish habitat using River2D, WUA (Weighted Usable Area) was estimated 107,392.0 m²/1000 m under the ecological flow condition and it showed the fish habitat was secured throughout the target stream compared with Q₃₅₅ condition.

• Journal of Korea Water Resources Association
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• v.55 no.8
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• pp.603-611
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• 2022

In urban areas, the impermeable area continues to increase due to urbanization, which interferes with the surface penetrating and infiltrating of rainwater, causing most rainwater runoff to the surface, deepening the distortion of water circulation. Distortion of water circulation affects not only flood disasters caused by rainfall and runoff, but also various aspects such as dry stream phenomenon, deterioration of water quality, and destruction of ecosystem balance, and the Ministry of Environment strongly recommends the use of Low Impact development (LID) techniques. In order to apply the LID technique, it is necessary to set a rainwater management target to handle the increase in outflow after the development of the target site, and the current standard sets the rainwater management target using the 10-year daily rainfall. In this study, the difference from the current standards was analyzed through statistical analysis and classification of independent rainfall ideas using inter-event time definition (IETD) in setting the target amount of rainwater management to improve water circulation. Using 30-year rainfall data from 1991 to 2020, methods such as autocorrelation coefficient (AC) analysis, variation coefficient (VC) analysis, and annual average number of rainfall event (NRE) analysis were applied, and IETD was selected according to the target rainfall period. The more samples the population had, the more IETD tended to increase. In addition, by analyzing the duration and time distribution of independent rainfall according to the IETD, a plan was proposed to calculate the standard design rainfall according to the rainwater management target amount. Therefore, it is expected that it will be possible to set an improved rainwater management target amount if sufficient samples of independent rainfall ideas are used through the selection of IETD as in this study.

• Journal of the Korean Burn Society
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• v.24 no.2
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• pp.21-29
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• 2021

Purpose: Frostbite is a hazard to people exposed to cold environments. With the progression of modern industrial development and change of leisure behavior encountering cold environments, frequent accidental exposure to frostbite injury during work and human behavior is increasing, and the predisposing factors of frostbite were greatly changed than before. The purpose of this study was to make epidemiological analysis, and to review the treatment outcomes of frostbite. Methods: From March 2010 to February 2021, this study has included 27 patients with second- to third-degree frostbite injuries in Advanced Burn Reconstruction Center, Bundang Jesaeng Hosptial. A retrospective study was made about the distribution of age, gender, predisposing factors, prevalent area, type of managements, and the length of treatment period. Results: In our institution, acute management of frostbite patients has included rewarming, anticoagulation therapy (acetylsalicylic acid), and agents to improve vascular perfusion (lipo-prostaglandin E1 [Eglandin^®]). The 25 frostbite patients with second-degree frostbite (92.6%) were successfully managed by the conservative treatment alone with a mean of 20.3 days healing time. Two patients with third-degree frostbite (7.4%) also showed good outcomes after surgical reconstruction with a mean of 59 days healing time. In our clinical experiences of third-degree frostbite, definitive surgical reconstruction should be recommended to wait for more than 4~6 weeks for identification of clear demarcation of necrotic tissue caused by frostbite. In this study, 43 frostbite injuries site in 27 frostbite patients occurred. Among them, 15 patients (55.6%) had multiple-site frostbite injury. The most common predisposing cause of frostbite was refrigerant gas accidents (44.4%), followed by outdoor activity in cold environments (40.8%), misapplying ice pack for treatment purposes (7.4%), barefoot walking on the cold ground (3.7%), and loss of consciousness in cold grounds (3.7%). The most prevalent sites of frostbite injuries revealed as the hand (58.1%), followed by the foot (32.6%), face (7.0%), and abdomen (2.3%). And in the winter season from the November to March, the incidence rate of frostbite injuries was high at 74.1%. Conclusion: This study included 27 frostbite patients with 43 frostbite sites since last decade in a single institution at the community hospital. The frostbite patients with second-degree frostbite (92.6%) were successfully healed by the conservative treatment alone with a mean of 20.3 days healing time. The most common predisposing cause of frostbite was refrigerant gas accidents (44.4%), followed by outdoor activity in cold environments, etc. The most prevalent site of frostbite injuries was the hand (58.1%). And the most prevalent seasonal incidence of frostbite was from November to March (74.1%).

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.6
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• pp.27-36
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• 2021

At a time when the equitable use of urban parks is gradually emerging as a social issue, this study was initiated to expand the influence of urban parks by improving the quality of park services, thereby resolving areas not covered by urban park services. This study targeted the Hangang Park in Seoul, where the qualitative service of parks shows the greatest difference. The influence relationship between the qualitative services of the park and the user's sphere of influence, which indicates the distribution of park users, was proposed to assess the influence of improvements in the quality of service. As a research method, the top three districts and the bottom three districts were selected through the Han River Park user satisfaction survey conducted from 2017 to 2019, and a qualitative service evaluation was carried out. It was derived using the data acquired in September. Afterward, by performing a spatial autocorrelation analysis on the user's sphere of influence, additional verification of the user's sphere of influence was performed numerically and visually. As a result of the study, the user influence in the top three districts, with high-quality service, was stronger and wider than that of the lower three districts. It was confirmed that the quality of service of the park affects the user influence. This shows that to realize park equity, it is necessary to improve the quality of services through continuous management and improvement of individual parks and the creation of new parks. This study has significance in that it recognizes the limitations of research on park services from a supplier's point of view and evaluates the qualitative services of parks from the perspective of actual park users. We propose an alternative to deal with the lower the park deprivation index.