• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.565-575
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• 2021

The purpose of this study was to identify the amount of alcohol and drinking frequency among high school students based on social alcohol drinking supply. The data was on 161 drinkers aged between 16 and 19 from 21 high schools across the country using a questionnaire of the International Alcohol Control(IAC) Study, which was developed in 2012. Results show that the higher the number of social suppliers offering alcoholic beverages to high school students, the greater the consumption of alcohol per episode(59.433 g for one person, 113.40 g for two, and 133.56 g for three or more people). On the other hand, alcohol consumption among 'Honsul' people, a group that drinks alone without a social drinking supplier, was 167.84 grams, higher than that of groups that receive social drinking services. As a social drinking supplier for teenagers, drinking was the highest by their father (29.3 %), while friends (25.0 %) and mothers (20.7 %) were the main drinking suppliers. In particular, the provision of drinking due to father(𝛽=-.32, t=3.55, p<.01) and mother(𝛽=.22, t=2.71, p<.01) showed statistical significance as a factor in increasing the frequency of providing social drinking in adolescents. On the other hand, partner/boy or girl friend (𝛽=-.23, t=-2.73, p<.01) was a factor in reducing the frequency of alcohol provision. Friends(𝛽=.24, t=3.02, p<.01) and senior-junior schoolmates(𝛽=.16, t=2.04, p<.05) were the factors that increase the total alcohol intake of adolescents. This is due to the increase in the frequency of alcohol provision. This suggests that alcohol harm education should be expanded from students to parents, considering the role of parents as a social drinking supplier and the link between high alcohol intake among teenagers due to senior-junior friends and schoolmates.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.609-625
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• 2022

Validation of satellite data products is critical for subsequent analysis that is based on the data. Particularly, performance of ocean color products in turbid and shallow near-land ocean areas has been questioned for long time for its difficulty that stems from the complex optical environment with varying distribution of water constituents. Furthermore, validation with ship-based or station-based measurements has also exhibited clear limitation in its spatial scale that is not compatible with that of satellite data. This study firstly performed validation of major GOCI-II products such as remote sensing reflectance, chlorophyll-a concentration, suspended particulate matter, and colored dissolved organic matter, using the in-situ measurements collected from ship-based field campaign. Secondly, this study also presents preliminary analysis on the use of drone images for product validation. Multispectral images were acquired from a MicaSense RedEdge camera onboard a UAV to compensate for the significant scale difference between the ship-based measurements and the satellite data. Variation of water radiance in terms of camera altitude was analyzed for future application of drone images for validation. Validation conducted with a limited number of samples showed that GOCI-II remote sensing reflectance at 555 nm is overestimated more than 30%, and chlorophyll-a and colored dissolved organic matter products exhibited little correlation with in-situ measurements. Suspended particulate matter showed moderate correlation with in-situ measurements (R²~0.6), with approximately 20% uncertainty.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.447-460
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• 2022

It is well known that satellite synthetic aperture radar interferometry (InSAR) has been widely used for the observation of surface displacement owing to earthquakes, volcanoes, and subsidence very precisely. In wetlands where vegetation exists on the surface of the water, it is possible to create a water level change map with high spatial resolution over a wide area using the InSAR technique. Currently, a number of imaging radar satellites are in operation, and most of them support a ScanSAR mode observation to gather information over a large area at once. The Cienaga Grande de Santa Marta (CGSM) wetland, located in northern Colombia, is a vast wetland developed along the Caribbean coast. The CGSM wetlands face serious environmental threats from human activities such as reclamation for agricultural uses and residential purposes as well as natural causes such as sea level rise owing to climate change. Various restoration and protection plans have been conducted to conserve these invaluable environments in recognition of the ecological importance of the CGSM wetlands. Monitoring of water level changes in wetland is very important resources to understand the hydrologic characteristics and the in-situ water level gauge stations are usually utilized to measure the water level. Although it can provide very good temporal resolution of water level information, it is limited to fully understand flow pattern owing to its very coarse spatial resolution. In this study, we evaluate the L-band ALOS-2 PALSAR-2 ScanSAR mode to observe the water level change over the wide wetland area using the radar interferometric technique. In order to assess the quality of the interferometric product in the aspect of spatial resolution and coherence, we also utilized ALOS-2 PALSAR-2 stripmap high-resolution mode observations.

• Journal of the Korean Geotechnical Society
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• v.38 no.10
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• pp.61-74
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• 2022

Considering that the number of cases in which a structure foundation is located on weathered rock has been increasing recently, for adequate design bearing capacity of a foundation on weathered rock, allowable bearing capacities of such foundations in geotechnical investigation reports were studied. With reference to the study results, the allowable bearing capacity of a foundation on weathered rock was approximately 400-700 kN/m², with a large variation, and was considered a conservative value. Because the allowable bearing capacity of the foundation ground is an important index in determining the foundation type in the early design stage, it can have a significant influence on the construction cost and period according to the initial decision. Thus, in this study, six large-scale plate-bearing tests were conducted on weathered rock, and the bearing capacity and settlement characteristics were analyzed. According to the test results, the bearing capacities from the six tests exceeded 1,500 kN/m², and it shows that the results are similar with the one of bearing capacity formula by Pressuremeter tests when compared with the various bearing capacity formula. In addition, the elastic modulus determined by the inverse calculation of the load-settlement behavior from the large-scale plate-bearing tests was appropriate for applying the elastic modulus of the Pressuremeter tests. With consideration of the large-scale plate-bearing tests in this study and other results of plate-bearing tests on weathered rock in Korea, the allowable bearing capacity of weathered rock is evaluated to be over 1,000 kN/m². However, because the settlement of the foundation increases as the foundation size increases, the allowable bearing capacity should be restrained by the allowable settlement criteria of an upper structure. Therefore, in this study, the anticipated foundation settlements along the foundation size and the thickness of weathered rocks have been evaluated by numerical analysis, and the foundation size and ground conditions, with an allowable bearing capacity of over 1,000 kN/m², have been proposed as a table. These findings are considered useful in determining the foundation type in the early foundation design.

• Korean Journal of Environment and Ecology
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• v.36 no.4
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• pp.368-380
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• 2022

Biomonitoring of an invasive alien crayfish species, Procambarus clarkii (Girard, 1852), was performed from February to October 2021, along with environmental DNA analysis, at five locations including Wanju-gun, Hampyeong-gun, Naju-si, Gurye-gun, and Cheongju-si. For the investigation, an umbrella-shaped trap for adults and a hand net for young crayfish were used, and 8 to 10L of freshwater was collected for eDNA analysis. The current status and past distributional records of crayfish in Korea were analyzed along with benthic macroinvertebrates at each survey site. As a result of the investigation, a total of 122 individuals were identified, and Hampyeong-gun recorded the largest number of populations with 59 individuals (48.36%) and the highest environmental DNA (eDNA). The frequency of appearance of P. clarkii was highest in May. The ratio of females to males was 21:5, and the body size was 72.2±21.1mm for female, 80.5±15.6mm for male, and 25.3±9.8mm for young crayfish. P. clarkii introduced into Korea is mainly spreading in the southwest region and it has not been observed in Seoul where there had been a record of appearance in the past. No external symbiosis (Branchiobdellida) of P. clarkii has been identified, and P. clarkii that has appeared in Korea was presumed to be imported from Japan. There are more than eight kinds of exotic crayfish distributed in Korea, and among them, the marbled crayfish (P. virginalis) was identified as a harmful species to the ecosystem of Korea by the Ministry of Environment in 2021. The identified species of benthic macroinvertebrates inhabiting the survey area where P. clarkii has appeared were 69 belonging to 39 families, 15 orders, five classes, and three phyla. Among them, Odonata were the most abundant (16 spp.; 24.62%), followed by Coleoptera (11 spp.; 16.92%) and Hemiptera (11 spp.; 16.92%). In the survey area, one Korean endemic species (Rhoenanthus coreanus), one species (Helophorus auriculatus) classified as Near Threatened (NT) on the Korean Red List, and six species of Crustaceans appeared. In the functional feeding group, the predators appeared predominantly while in habitat oriented group, the climbers appeared to be abundant. It was confirmed that P. clarkii in the survey area prefers an area rich in aquatic vegetation with waterside vegetation, and has high resistance to turbid water quality. The omnivore invader P. clarkii is expected to maintain a competitive relationship with carnivorous benthic macroinvertebrates that are predominant in the same species, and is expected to continue to generate ecosystem disturbance along the food chains.

• 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 Mushroom
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• v.20 no.3
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• pp.168-172
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• 2022

This study was conducted to investigate the optimum supplementation ratio when replacing cotton seed meal with rapeseed meal for cultivating oyster mushrooms. The chemical properties among the treatments were pH 4.5~4.7, total carbon content was 46.3~46.5%, total nitrogen content was 1.6~1.7%, and carbon-nitrogen ratio was 27.0~27.8. These did not differ significantly from the control. Mycelial growth was 85.1 mm (Heuktari), and 72.8 mm (Suhan-1Ho) in medium containing 5% rapeseed meal, with no significant difference in mycelial density between cultivars. Fruiting body characteristics are as follows: In 'Heuktari', the color of the pileus was darker than control with an L value of 32.5, and pileus thickness and diameter were 3.2 mm and 27.6 mm, respectively. Stipe length and diameter were 86.0 mm and 9.1 mm, respectively. Valid stipe number per bottle (1,100 cc) was 25.9, and a yield of 189.7 g/1,100 cc was recorded in mixed medium containing 5% rapeseed meal (higher than control). In mixed medium containing 10% rapeseed meal, the yield was 184.5 g/1,100 cc (comparable to control). In 'Suhan-1Ho', supplemented with 5% rapeseed meal, pileus color was darker than control color, with an L value of 28.8. Pileus thickness was 4.5 mm. Stipe diameter was 12.3 mm (higher than control), and yield was 145.5 g/1,100 cc (comparable to control).

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.468-475
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• 2022

This study was conducted to find out the efficiency of heating initiative temperature and carbon dioxide fertilization in summer squash (Cucurbita moschata D.). The heating start temperature experiment was performed at 9℃, 12℃, and 15℃ using an electric heater and operated when the temperature was lower than the target temperature. The CO₂ fertilization concentration experiment was performed from 7 to 12 with the control, 500 µmol·mol^-1, and 800 µmol·mol^-1 using liquefied carbon dioxide. Investigation items were plant height, stem diameter, number of leaves, leaf area, fresh weight, dry weight, also economic analysis was conducted by surveying only fruits exceeding 100 g. Photosynthesis was measured for the upper leaf position to calculate the saturation point according to the control. The photo saturation point was 587 µmol·m^-2·s^-1, and the CO₂ saturation point was 702 µmol·mol^-1. A_max values by carbon dioxide were 13.4, 17.8, 17.2, 19.6, and 17.5 µmolCO₂·m^-2·s^-1 in the order of 9℃, 12℃, 15℃, 500 µmol·mol^-1, and 800 µmol·mol^-1. In the temperature experiment, 9℃ in growth did not grow normally and no fruiting was performed. 12℃ and 15℃ were higher than 9℃, but there was no significant difference in growth and production. The CO₂ fertilization experiment showed no significant difference between the treatment in growth, but the productivity of 800 µmol·mol^-1 was the best. Comprehensively, the heating initiative temperature of 15℃ was good for crop growth and production, but there is no significant difference from 12℃, so it is good to set the heating start temperature to 12℃ economically, and maintaining of 800 µmol·mol^-1 is effective in increasing production.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.1
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• pp.37-42
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• 2021

Munseom (Island) is known as the largest native Elaeocarpus sylvestris var. ellipticus in Korea. Recently, disease damage from the E. sylvestris var. ellipticus community has been reported in Munseom. This study was conducted to understand the damage situation and growth characteristics of the E. sylvestris var. ellipticus population in Munseom. The purpose of this study was to evaluate the spontaneous regeneration potential of the community by grasping the characteristics of the population of surviving E. sylvestris var. ellipticus individuals, and to discuss ways to restore native habitats. A total population survey was conducted to determine the distribution status of E. sylvestris var. ellipticus individuals. The field survey carefully recorded the height of tree, DBH, DRH, and growing status, along with GPS location information of the individual. The growth status of E. sylvestris var. ellipticus individuals distributed in Munseom and the characteristics of tree height, DBH, DRH of each individual were analyzed. The total number of E. sylvestris var. ellipticus populations identified in Munseom was 293. The dense E. sylvestris var. ellipticus community reported in 2005 has been identified as being greatly damaged or damaged. In particular, the damage was more serious in mature trees with a height of 6m or more forming the canopy layer in the forest, and it was confirmed that 80.6% of the mature trees died. In the growth characteristics of the old-growth tree, which is an indicator of the health of the forest based on DRH, 75.4% died or the growth condition was found to be poor. In order to restore the native habitat of E. sylvestris var. ellipticus in Munseom, conservation efforts such as pest control, preservation of mature trees, control of the territory of young trees, and reintroduction after ex-situ transplantation etc. are considered necessary.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.285-297
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• 2021

Globally, nuclear-decommissioning facilities have been increased in number, and thereby hundreds of thousands of wastes, such as concrete, soil, and metal, have been generated. For this reason, there have been numerous efforts and researches on the development of technology for volume reduction and recycling of solid radioactive wastes, and this study reviewed and examined thoroughly such previous studies. The waste concrete powder is rehydrated by other processes such as grinding and sintering, and the processes rendered aluminate (C3A), C4AF, C3S, and ��-C2S, which are the significant compounds controlling the hydration reaction of concrete and the compressive strength of the solidified matrix. The review of the previous studies confirmed that waste concretes could be used as recycling cement, but there remain problems with the decreasing strength of solidified matrix due to mingling with aggregates. There have been further efforts to improve the performance of recycling concrete via mixing with reactive agents using industrial by-products, such as blast furnace slag and fly ash. As a result, the compressive strength of the solidified matrix was proved to be enhanced. On the contrary, there have been few kinds of researches on manufacturing recycled concretes using soil wastes. Illite and zeolite in soil waste show the high adsorption capacity on radioactive nuclides, and they can be recycled as solidification agents. If the soil wastes are recycled as much as possible, the volume of wastes generated from the decommissioning of nuclear power plants (NPPs) is not only significantly reduced, but collateral benefits also are received because radioactive wastes are safely disposed of by solidification agents made from such soil wastes. Thus, it is required to study the production of non-sintered cement using clay minerals in soil wastes. This paper reviewed related domestic and foreign researches to consider the sustainable recycling of concrete waste from NPPs as recycling cement and utilizing clay minerals in soil waste to produce unsintered cement.