• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.722-732
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• 2021

Purpose: Due to the coronavirus infection-19 (COVID) pendemics, all educational institutions were required to provide full non-face-to-face real-time education, and fire officials were required to provide fire-fighting education by applying non-face-to-face education. In this difficult situation, the National Fire Service Academy tries to find the direction of the non-face-to-face real-time education and suggest ways to improve it through a survey of the status of non-face-to-face real-time education conducted by the NFSA to fire officials. Method: A survey was conducted on fire officials under the theme of "Consciousness Survey for Improving the Quality and Specialization of Non-face-to-face Real-Time Remote Education" and an in-depth analysis was conducted based on the results. Result & Conclusion: First, professors or educational operators shall actively utilize remote education programs suitable for educational characteristics by utilizing various programs. Second, a dedicated notebook for non-face-to-face training should be provided to provide an educational environment where all learners can participate in the training without difficulty. Third, in the case of education and training that requires the use of equipment due to the nature of fire officials' education and training, it is necessary to consider it as a non-face-to-face training place by arranging educational equipment at each fire station. Fourth, it is hard to expect a satisfactory educational effect to cope with practical education with theoretical education. Therefore, facilities and programs that enable non-face-to-face real-time hands-on training should be developed. It is worth considering the proper combination of face-to-face education while maintaining the social distance as much as possible until such non-face-to-face training is possible. Fifth, non-face-to-face education is considered to have high eye fatigue due to the light and electromagnetic waves of the computer screen, and as time goes by, the concentration level decreases. Therefore, it is necessary to form an education time to reduce the eye fatigue of learners and increase concentration through proper class and rest time. Finally, professors should operate a learner participation-oriented education that allows professors and learners to interact rather than one-sided knowledge transfer education. In addition, technical problems of non-face-to-face remote education should be thoroughly prepared through preliminary system checks to ensure that education is not disrupted.

• 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.

• Journal of the Society of Disaster Information
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• v.18 no.2
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• pp.280-289
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• 2022

Purpose: In this study, the characteristics of fire occurrence according to ignition heat sources such as operating equipment, cigarette/lighter fire, and flame/fire were analyzed. Method: One-way ANOVA and cross-analysis were used to analyze the characteristics of fire occurrence by verifying the difference between the ignition environment, fire damage status and scale, and cause of ignition according to the ignition heat source. Result: The fire occurrence characteristics were analyzed through As a result of the analysis, it was found that fires caused by operating devices occurred more frequently on weekdays than other ignition heat sources, and the number of victims and the number of victims were the highest, so mobilization of firefighting power and property damage were the greatest. The initial ignition was generated by electric and electronic devices, and the combustion was expanded by the synthetic resin. For fires caused by cigarette and lighter fires, the most fires occurred on Saturdays and Sundays, and the mobilization of the police force was more characteristic than the mobilization of the firefighting force. In particular, it was found that the initial ignition and combustion expansion were caused by paper, wood, and hay. Fires caused by sparks and sparks occurred most frequently on Saturdays and Sundays, and initial ignition and combustion expansion were found to be caused by paper, wood, and hay. In particular, it showed the characteristic that it occurred in the place farthest from the fire station. The common characteristic of all ignition heat sources was that the fire occurred most frequently in the afternoon time, and the fire type was predominantly the building structure fire, and only the ignition point was burned the most. Conclusion: In order to prevent fire and minimize damage, it is necessary to analyze the tendency of fire occurrence and to prepare appropriate preparations according to the fire occurrence factors. In order to analyze the characteristics of fire occurrence using public data in the future, it is necessary to standardize disaster data and to open and activate data.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.853-865
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• 2022

In this study, from August to October 2019, we conducted a survey of the spatial distribution and dominant species of macrobenthos on the rocky intertidal zones of 38 specified islands distributed along the southern coast of Korea. On the basis of observation made using 50 × 50 cm quadrats, we identified a total of 80 species, among which, Mollusca were the most abundant fauna, with 54 species that accounted for 67.4% of the total, followed by Crustacea with 15 species (18.7%). The recorded numbers of Cnidaria, Porifera, and Echinodermata species ranged from 1 to 6. In terms of the regional patterns of species richness, specified islands in Yeosu were found to be the most species rich, supporting 61 species, whereas islands in Hadong, Namhae, and Chujado were found to have a similar level of species richness, ranging from 42 to 46 species. Islands in Boseong and Goheung were home to the fewest species, with only 29 species being recorded. At the sampling station scale, we noted a considerable difference in faunal richness, ranging from 6 (St. 6) to 33 (St. 20) species. Among the recorded species, Echinolittorina radiata was identified as the dominant species on 15 specified islands, with the next most abundant species being Tetraclita japonica, considered an indicator species of climate change, which was recorded on 11 islands. In terms of frequency, E. radiata, found on 36 islands, was identified as the most frequently occurring species, followed by Reishia clavigera (30 islands), Mytilisepta virgata (29), Nerita japonica (28), Ligia. exotica (27), and Littorina brevicula (26). Of the 80 species identified, 9, 4, and 2 species of Mollusca, Crustacea, and Cnidaria, respectively, are classified as Marine fauna of accepted foreign export, whereas 50 are Red List species, 44 are species of Least Concern, 3 are Data Deficient species, and 1 species was not evaluated. However, during the survey, we found no Near Threatened or Not Applicable species. On the basis of the findings of this survey, it would appear that the abundance and richness of macrobenthic fauna inhabiting the rocky intertidal zones of specified islands along the southern coast of Korea differ according to different habitat conditions, particularly with respect to the duration of exposure and the extent and properties of the substrata. The findings of this study will provide baseline data for future monitoring and management of specified islands in Korea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.2
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• pp.103-125
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• 2022

This study aims to identify the community characteristics of meiofauna inhabiting the Yellow Sea continental shelf. To this end an annual survey was conducted considering the seasons from 2018 to 2020 at 13 stations with a depth of 18~90 m of the Yellow Sea located at latitudes 35, 36 and 37 degrees north latitude. The survey was conducted in three seasons of spring, summer, and autumn at 5 stations in October 2018, 9 stations in April 2019, and 6 stations in August 2020 was used to collect 3 repetitions at each station. The habitat density of meiobenthos in the surveyed area was in the range of 45~1029 inds./10 cm², which was similar to the previous studies conducted in the Yellow Sea. The density of meiobenthos according to the seasons was 800±69 inds./10 cm² in autumn, the highest, and the lowest at 260±48 inds./10 cm² in summer. A total of 19 taxa appeared in meiobenthos, and the average value showed the number of nine taxa. Among the appearing taxa, the most dominant taxon was nematodes, accounting for 80.8% of the total density, followed by benthic copepods (8.8%) and benthic foraminifers (4.7%). As for the size distribution of medium benthic animals, the density of organisms corresponding to the size of 63~125 ㎛ was the highest, and 1~0.5 mm was the lowest. As for the vertical distribution in the sediments of medium benthic animals, the habitat density gradually decreased as the depth increased in the sediment surface layer. As a result of analysis of the N/C ratio, MPI, and ITD index using medium-sized benthic animals to identify the benthic environment, there were differences by season, but no values indicating pollution overall.

• 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_3
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• pp.939-951
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• 2022

The most important factor in designing autonomous driving systems is to recognize the exact location of the vehicle within the surrounding environment. To date, various sensors and navigation systems have been used for autonomous driving systems; however, all have limitations. Therefore, the need for high-definition (HD) maps that provide high-precision infrastructure information for safe and convenient autonomous driving is increasing. HD maps are drawn using three-dimensional point cloud data acquired through a mobile mapping system (MMS). However, this process requires manual work due to the large numbers of points and drawing layers, increasing the cost and effort associated with HD mapping. The objective of this study was to improve the efficiency of HD mapping by segmenting semantic information in an MMS point cloud into six classes: roads, curbs, sidewalks, medians, lanes, and other elements. Segmentation was performed using various machine learning techniques including random forest (RF), support vector machine (SVM), k-nearest neighbor (KNN), and gradient-boosting machine (GBM), and 11 variables including geometry, color, intensity, and other road design features. MMS point cloud data for a 130-m section of a five-lane road near Minam Station in Busan, were used to evaluate the segmentation models; the average F1 scores of the models were 95.43% for RF, 92.1% for SVM, 91.05% for GBM, and 82.63% for KNN. The RF model showed the best segmentation performance, with F1 scores of 99.3%, 95.5%, 94.5%, 93.5%, and 90.1% for roads, sidewalks, curbs, medians, and lanes, respectively. The variable importance results of the RF model showed high mean decrease accuracy and mean decrease gini for XY dist. and Z dist. variables related to road design, respectively. Thus, variables related to road design contributed significantly to the segmentation of semantic information. The results of this study demonstrate the applicability of segmentation of MMS point cloud data based on machine learning, and will help to reduce the cost and effort associated with HD mapping.

• Ecology and Resilient Infrastructure
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• v.8 no.2
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• pp.79-87
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• 2021

Because active interactions occur among vegetation, hydrology, and geomorphology in riparian systems, any changes in one of these factors can significantly affect the other two. In this study, we evaluated these interactions at four sites (two in Gajeong and two in Hahan) along the Seomjin-gang River that was substantially devastated by an extreme flood in 2020. We examined the relationship between the riparian vegetation and the hydraulic characteristics of the flood using remote sensing, hydraulic modeling, and field surveys combined. The evaluation results showed that the floods caused a record-breaking rise of up to 43.1 m above sea level at the Yeseong-bridge stage gauge station (zero elevation 27.4 m) located between the Gajeong and Hahan sites, with the shear stress being four times higher in Hahan than in Gajeong. Additionally, the water level during the flood was estimated to be a maximum of 1 m higher depending on the location in the presence of riparian plants. Furthermore, both sites underwent extensive biological damage due to the flood, with 78-80% loss in vegetation, with preferential damage observed in large willow species, compared to Quercus acutissima. The above findings imply that all plant species exhibit different vulnerabilities towards extreme floods and do not induce similar behavior towards events causing a disturbance. In conclusion, we developed strategies for effectively managing riparian trees by minimizing flood hazards that could inevitably cause damage.

• Journal of Popular Narrative
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• v.26 no.1
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• pp.135-174
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• 2020

The article focuses on the student activism experience of the 1990s and 2010s and on the accumulation of everyday experiences created by the conditions of the 2010s against the backdrop of differences in how the composition of 'we' is portrayed in oral narrative. What stands out in the 90s oral narratives on student activism experiences, which were compiled in the 2010s, is the distancing of the culture of student activism at that time. In the words of speakers who experienced university life in the 1990s, the culture of student activism at the university was created through private relationships, and was, needless to say, considered 'natural'. At the same time, however, the 'natural' is said to be 'abnormal' or 'strange' in the context of the 2010s in which it is being talked about, and is meant to be an experience with a certain distance from the present speakers. This aspect is associated with the conditions under which the experience of the 90s is being described in the 2010s. The present, which explains past experiences to speakers, was explained after the 2016 candlelight protest and Gangnam Station femicide protest, and is described as a world that is qualitatively different from before, and is located as an opportunity to create a critical distance from past experiences. This qualitative change, which raises suspicions about the homogenous "we", is based on a newly acquired sense of gender sensitivity, living since the mid-2010s, when gentler issues were the biggest topic in Korean society, among others. In the 2010s, the composition of 'we' is no longer understood as a community of people who share any commonality, but as individuals who unite despite numerous differences. This reveals the experiences of those who have already embodied this in their everyday senses in the 2010s. The 'we' they formed should have nothing to do with private relationships, nor was homogeneity considered the most prominent group, so it was nothing that could explain the 'me' at the time of the demonstration and outside of the venue. It was in that context that the relevant experience was described in a cautious manner throughout. This, in turn, raises the need to ask and understand a new sense of student activism and, moreover, social movements and the sense of unity as 'we'. It should also be asked who is the main body of the movement and what is the use of asking it. Soon, the need and meaning of defining the fixed identity of 'we' in the movement should be questioned. Therefore, it should be asked what fixed positions or coordinates can really represent someone's position.

• 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.