• Journal of Korea Water Resources Association
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• v.54 no.spc1
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• pp.1107-1118
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• 2021

Climate change brought on by global warming increased the frequency of flood and drought on the Korean Peninsula, along with the casualties and physical damage resulting therefrom. Preparation and response to these water disasters requires national-level planning for water resource management. In addition, watershed-level management of water resources requires flow duration curves (FDC) derived from continuous data based on long-term observations. Traditionally, in water resource studies, physical rainfall-runoff models are widely used to generate duration curves. However, a number of recent studies explored the use of data-based deep learning techniques for runoff prediction. Physical models produce hydraulically and hydrologically reliable results. However, these models require a high level of understanding and may also take longer to operate. On the other hand, data-based deep-learning techniques offer the benefit if less input data requirement and shorter operation time. However, the relationship between input and output data is processed in a black box, making it impossible to consider hydraulic and hydrological characteristics. This study chose one from each category. For the physical model, this study calculated long-term data without missing data using parameter calibration of the Soil Water Assessment Tool (SWAT), a physical model tested for its applicability in Korea and other countries. The data was used as training data for the Long Short-Term Memory (LSTM) data-based deep learning technique. An anlysis of the time-series data fond that, during the calibration period (2017-18), the Nash-Sutcliffe Efficiency (NSE) and the determinanation coefficient for fit comparison were high at 0.04 and 0.03, respectively, indicating that the SWAT results are superior to the LSTM results. In addition, the annual time-series data from the models were sorted in the descending order, and the resulting flow duration curves were compared with the duration curves based on the observed flow, and the NSE for the SWAT and the LSTM models were 0.95 and 0.91, respectively, and the determination coefficients were 0.96 and 0.92, respectively. The findings indicate that both models yield good performance. Even though the LSTM requires improved simulation accuracy in the low flow sections, the LSTM appears to be widely applicable to calculating flow duration curves for large basins that require longer time for model development and operation due to vast data input, and non-measured basins with insufficient input data.

• The Journal of Sustainable Design and Educational Environment Research
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• v.21 no.3
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• pp.1-13
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• 2022

This study is a case study to identify the spatial composition and structural problems of existing schools for spatial innovation as a future school that can operate a credit system for old high schools and establish a mid-to-long-term arrangement plan as a credit system operating school capable of various teaching and learning in the future. The study results are as follows: First, most of the problems of the old high schools entailed that there was very poor connectivity between buildings as most of them were arranged in a single, standard design-type unit building and distributed in multiple buildings. In addition, the floor plan of each building is suggested to be a structure in which student exchange and rest functions cannot be achieved during the break period due to the spatial composition of the classroom and hallway concepts. Second, in the direction of the high school space configuration for future school space innovation, the arrangement plan should be established by reflecting the collective arrangement in consideration of the shortening of the movement route and the expansion of subject areas due to the movement of students on the premise of the subject classroom system. Moreover, it is desirable to provide a square-type space for rest and exchange in the central area where communication and exchange are possible according to the moving class. Third, as the evaluation criteria for relocating old high schools, a space program is prepared based on the number of classes in the future, and legal analysis of school land use and land use efficiency analysis considering regional characteristics are conducted. Based on such analysis data, mid-to-long-term land use plans and space arrangement plans for the entire school space such as the school facility complex are established.

• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.240-249
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• 2022

Measuring chlorophyll fluorescence (CF) is a useful tool for assessing a plant's ability to tolerate abiotic stresses such as drought, waterlogging and high temperature. Korean ginseng is highly sensitive to water stress in paddy fields. To evaluate the possibility of non-destructively diagnosing waterlogging stress using chlorophyll fluorescence (CF) imaging techniques, we screened 57 ginseng accessions for waterlogging tolerance. To evaluate waterlogging tolerance among the 2-year-old Korean ginseng accessions, we treated ginseng plants with water stress for 25 days. The physiological disorder rate was characterized through visual assessment (an assigned score of 0-5). The physiological disorder rates of Geumjin, Geumsun and GS00-58 were lower than that of other accessions. In contrast, lines GS97-62, GS97-69 and GS98-1-5 were deemed susceptible. Root traits, chlorophyll content and the reduction rates decreased in most ginseng accessions. Further, these metrics were significantly lower in susceptible genotypes compared to resistant ones. All CF parameters showed a positive or negative response to waterlogging stress, and this response continuously increased over the treatment time among the genotypes. The CF parameter Fv/Fm was used to screen the 57 accessions, and the results showed clear differences in Fv/Fm between the susceptible and resistant genotypes. Susceptible genotypes had an especially low Fv/Fm value of less than 0.8, reflecting damage to the reaction center of photosystem II. It is concluded that Fv/Fm can be used as a CF parameter index for screening waterlogging stress tolerance in ginseng genotypes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.256-266
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• 2022

Empirical models including the Angstrom-Prescott (AP) model have been used to estimate solar radiation at sites, which would support a wide use of crop models. The objective of this study was to estimate two sets of solar radiation estimates using the AP coefficients derived for climate zone (AP_Frere) and specific site (AP_Choi), respectively. The daily solar radiation was estimated at 18 sites in Korea where long-term measurements of solar radiation were available. In the present study, daily solar radiation and sunshine duration were collected for the period from 2012 to 2021. Daily weather data including maximum and minimum temperatures and rainfall were also obtained to prepare input data to a process-based crop model, CERES-Rice model included in Decision Support System for Agrotechnology Transfer (DSSAT). It was found that the daily estimates of solar radiation using the climate zone specific coefficient, SFrere, had significantly less error than those using site-specific coefficients S_Choi (p<0.05). The cumulative values of S_Frere for the period from march to September also had less error at 55% of study sites than those of S_Choi. Still, the use of S_Frere and S_Choi as inputs to the CERES-Rice model resulted in slight differences between the outcomes of crop growth simulations, which had no significant difference between these outputs. These results suggested that the AP coefficients for the temperate climate zone would be preferable for the estimation of solar radiation. This merits further evaluation studies to compare the AP model with other sophisticated approaches such as models based on satellite data.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.4
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• pp.365-372
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• 2022

Cellobiose is a dissacharide constituted by two glucose units joined by a β-('1,4') glycosidic bond that is produced by the decomposition of cellulose. This product exists naturally in plants and has been utilized in different industries as a food sweetener, and as a cosmetic and pharmaceutical material. In this study, the potential of cellobiose as a whitening cosmetic product was evaluated by analyzing autophagy induction and the inhibition of melanin production. A cytotoxicity test conducted in the human melanin-producing cell line MNT-1 with increasing concentrations of cellobiose revealed that this compound did not cause cytotoxicity at 20 mg/mL or less. Based on this, autophagy was firstly evaluated by immunostaining with the autophagy marker microtubule-associated protein 1 light chain 3 (LC3) after treatment with 20 mg/mL of cellobiose. The subsequent confocal microscopy analysis revealed an increase in LC3 puncta, indicating induction of autophagy. In addition, autophagy was further confirmed by western blot analysis, which demonstrated that cellobiose converted LC3-I to LC3- ∏ in a concentration- and time-dependent manners. An analysis of melanin contents after cellobiose treatment at a concentration of 20 mg/mL during 7 days revealed that melanin production was reduced by more than 50%. Additionally, the expression levels of melanogenesis-related proteins TYR and TYRP1 were markedly decreased after cellobiose treatment. Based on these studies, a cosmetic cream formulation containing cellobiose was prepared and the change in formulation was tested for 4 weeks, and it was confirmed that the appearance changed to liquid form at high temperature, but the pH did not change. In conclusion, the present research demonstrated that cellobiose activates autophagy and inhibits melanin production, and showed the potential of this product as a material for whitening cosmetics.

• Journal of Food Hygiene and Safety
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• v.37 no.6
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• pp.400-410
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• 2022

This study was performed to analyze the microbial contamination levels of three non-heated rice cake manufacturers in terms of seasonal manufacturing process and to investigate the effects of summertime soaking on contamination levels and temperature-controlled soaking in water on reduction in microbial levels. The total aerobic bacteria (TAB) ranged from 2.69 log CFU/g to 5.08 log CFU/g in the produce, but the microbial contamination increased sharply during soaking. The levels of TAB and coliforms during summer soaking were 7.01 and 3.96 log CFU/g, respectively, and this was significantly higher than those in other seasons. The contamination level was high in the subsequent freezing, with the TAB level (6.24 log CFU/g) exceeding the legal standard. The temperature of soaking water in summer increased from 19.1℃ to 26.8℃ after 12 h of soaking. The microbial contamination was significantly high commensurate with increased soaking time, and the TAB level in the frozen process exceeded the legal standard from 9 h of soaking. The use of ice packs to prevent the increase in temperature of the soaking water in summer resulted in maintenance of temperature at 20.1℃ for up to 12 h. The average TAB value in the freezing process was 4.42 log CFU/g after 12 h of soaking, and this is 1.77 log CFU/g lower than that before. Based on these results, it was determined that controlling the soaking time and water temperature are essential for the production of a safe unheated frozen rice cake. The safety of the HACCP system could be established by applying these preventive management standards.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.651-662
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• 2022

The electrochemical impedance spectroscopy(EIS) method was used to evaluate the concrete deterioration process related to chloride-induced steel corrosion with various corrosion levels(initiation, rust propagation and acceleration periods). The impressed current technique, with four total current levels of 0C, 13C, 65C and 130C, was used to accelerate steel corrosion in concrete cylinder samples with w/c ratio of 0.4, 0.5, and 0.6, immersed in a 0.5M NaCl solution. A series of EIS measurements was performed to monitor concrete deterioration during the accelerated corrosion test in this study. Some critical parameters of the equivalent circuit were obtained through the EIS analysis. It was observed that the charge transfer resistance(R_c) dropped sharply as the impressed current increased from 0C to 13C, indicating a value of approximately 10kΩcm². However, the sensitivity of R_c significantly decreased when the impressed current was further increased from 13C to 130C after corrosion of steel had been initiated. Meanwhile, the double-layer capacitance value(C_dl) linearly increased from 50×10^-6μF/cm² to 250×10^-6μF/cm² as the impressed current in creased from 0C to 130C. The results in this study showed that monitoring C_dl is an effective measurement parameter for evaluating the progress of internal concrete damages(de-bonding between steel and concrete, micro-cracks, and surface-breaking cracks) induced by steel corrosion. The findings of this study provide a fundamental basis for developing an embedded sensor and signal interpretation method for monitoring concrete deterioration due to steel corrosion at various corrosion levels.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.246-254
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• 2022

Domestic facility agriculture grows rapidly, such as modernization and large-scale. And the production scale increases significantly compared to the area, accounting for about 60% of the total agricultural production. Greenhouses require energy input to create an appropriate environment for stable mass production throughout the year, but the energy load per unit area is large because of low insulation properties. Through the rooftop greenhouse, one of the types of urban agriculture, energy that is not discarded or utilized in the building can be used in the rooftop greenhouse. And the cooling and heating load of the building can be reduced through optimal greenhouse operation. Dynamic energy analysis for various environmental conditions should be preceded for efficient operation of rooftop greenhouses, and about 40% of the solar energy introduced in the greenhouse is energy exchange for crops, so it should be considered essential. A major analysis is needed for each sensible heat and latent heat load by leaf surface temperature and evapotranspiration, dominant in energy flow. Therefore, an experiment was conducted in a rooftop greenhouse located at the Korea Institute of Machinery and Materials to analyze the energy exchange according to the growth stage of crops. A micro-meteorological and nutrient solution environment and growth survey were conducted around the crops. Finally, a regression model of leaf temperature and evapotranspiration according to the growth stage of leafy vegetables was developed, and using this, the dynamic energy model of the rooftop greenhouse considering heat transfer between crops and the surrounding air can be analyzed.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.128-139
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• 2022

This study aimed to investigate the tectonic setting of the volcanic edifice at Mt. Baekdu by analyzing petrochemical characteristics of Holocene felsic volcanic rocks distributed in the Baekdusan stratovolcano edifice and summit of the Cheonji caldera rim, as well as Pleistocene mafic rocks of the Gaema lava plateau and Changbaishan shield volcano edifice. During the early eruption phases, mafic eruption materials, with composition ranging from alkali basalt to trachybasalt, or from subalkaline (tholeiitic) basalt to basaltic andesite formed the Gaema lava plateau and Changbaishan shield volcanic edifice, whereas the Baekdusan stratovolcano edifice and Holocene tephra deposits near the summit of the Cheonji caldera comprises trachytic and rhyolitic compositions. Analysis results revealed bimodal compositions with a lack of 54-62 SiO₂, between the felsic and mafic volcanic rocks. This suggested that magmatic processes occurred at the locations of extensional tectonic settings in the crust. Mafic volcanic rocks were plotted in the field of within-plate volcanic zones or between within-plate alkaline and tholeiite zones on the tectonic discrimination diagram, and it was in good agreement with the results of the TAS diagram. Felsic volcanic rocks were plotted in the field of within-plate granite tectonic settings on discrimination diagrams of granitic rocks. None of the results were plotted in the field of arc islands or continental margin arcs. The primitive mantle-normalized spider diagram did not show negative (-) anomalies of Nb and Ti, which are distinctive characteristics of subduction-related volcanic rocks, but exhibited similar patterns of ocean island basalt. Trace element compositions showed no evidence of, magmatic processes related to subduction zones, indicating that the magmatic processes forming the Baekdusan volcanic field occurred in an intraplate environment. The distribution of shallow earthquakes in this region supports the results. The volcanic rocks of the Baekdusan volcanic field are interpreted as the result of intraplate volcanism originating from the upwelling of mantle material during the Cenozoic era.

• Journal of agricultural medicine and community health
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• v.47 no.3
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• pp.166-180
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• 2022

Objective: This study evaluated the effects of a non-face-to-face obesity management program, implemented during the pandemic. Methods: The non-face-to-face obesity management program used the Intervention mapping protocol (IMP). The program was put into effect over the course of eight weeks, from September 14 to November 13, 2020 in 48 overweight and obese adults, who applied to participate through the Daegu Citizen Health Support Center. Results: IMP was first a needs assessment was conducted; second, goal setting for behavior change was established; third, evidence-based selection of arbitration method and performance strategy was performed; fourth, program design and validation; fifth, the program was run; and sixth, the results were evaluated. The average weight after participation in the program was reduced by 1.2kg, average WC decreased by 3cm, and average BMI decreased by 0.8kg/m² (p<0.05). The results of the health behavior survey showed a positive improvement in lifestyle factors, including average daily intake calories, fruit intake, and time spent in walking exercise before and after participation in the program. A statistically significant difference was seen (p<0.05). The satisfaction level for program process evaluation was high, at 4.57±0.63 point. Conclusion: The non-face-to-face obesity management program was useful for obesity management for adults in communities, as it enables individual counseling by experts and active participation through self-body measurement and recording without restriction by time and place. However, the program had some restrictions on participation that may relate to the age of the subject, such as skill and comfort in using a mobile app.