• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.589-597
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• 2023

Floating debris in large quantities from land during heavy rainfall has adverse social, economic, and environmental impacts, but the monitoring system for the concentration area and amount is insufficient. In this study, we proposed an efficient monitoring method for floating debris entering the river during heavy rainfall in Daecheong Lake, the largest water supply source in the central region, and applied remote sensing techniques to estimate the standing-stock of floating debris. To investigate the status of floating debris in the upper of Daecheong Lake, we used a tracking buoy equipped with a low-orbit satellite communication terminal to identify the movement route and behavior characteristics, and used a drone to estimate the potential concentration area and standing-stock of floating debris. The location tracking buoys moved rapidly during the period when the cumulative rainfall for 3 days increased by more than 200 to 300 mm. In the case of Hotan Bridge, which showed the longest distance, it moved about 72.8 km for one day, and the maximum moving speed at this time was 5.71 km/h. As a result of calculating the standing-stock of floating debris using a drone after heavy rainfall, it was found to be 658.8 to 9,165.4 tons, with the largest amount occurring in the Seokhori area. In this study, we were able to identify the main concentrations of floating debris by using location-tracking buoys and drones. It is believed that remote sensing-based monitoring methods, which are more mobile and quicker than traditional monitoring methods, can contribute to reducing the cost of collecting and processing large amounts of floating debris that flows in during heavy rain periods in the future.

• Korean Journal of Remote Sensing
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• v.39 no.5_3
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• pp.1031-1042
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• 2023

In this study, a deep learning model was developed to predict the yield of cabbage and radish, one of the five major supply and demand management vegetables, using satellite images of Landsat 8. To predict the yield of cabbage and radish in Gangwon-do from 2015 to 2020, satellite images from June to September, the growing period of cabbage and radish, were used. Normalized difference vegetation index, enhanced vegetation index, lead area index, and land surface temperature were employed in this study as input data for the yield model. Crop yields can be effectively predicted using satellite images because satellites collect continuous spatiotemporal data on the global environment. Based on the model developed previous study, a model designed for input data was proposed in this study. Using time series satellite images, convolutional neural network, a deep learning model, was used to predict crop yield. Landsat 8 provides images every 16 days, but it is difficult to acquire images especially in summer due to the influence of weather such as clouds. As a result, yield prediction was conducted by splitting June to July into one part and August to September into two. Yield prediction was performed using a machine learning approach and reference models , and modeling performance was compared. The model's performance and early predictability were assessed using year-by-year cross-validation and early prediction. The findings of this study could be applied as basic studies to predict the yield of field crops in Korea.

• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.393-404
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• 2023

The Natural Monument Forest (NMF) is a form of natural and cultural heritage that has symbolized the harmony between nature and culture in Korea for a long time. Recently, the NMF has deteriorated due to industrialization and reckless city expansion. Given this situation, it is necessary to preserve and manage the ecosystem of the NMF through preferential research regarding the forest community structure. Accordingly, this study sought to identify the community structure by analyzing the vegetation classification, stratum structure,and species diversity using vegetation data collected from the Forest of Japanese Torreyas in Pyeongdae-ri, Jeju and the Subtropical Forest of Nabeup-ri, Jeju. The results classified the forest vegetation as a Litsea japonica community group divided into two communities: a Torreya nuciferacommunity and a Quercus glauca community. The T. nuciferacommunity was subdivided into the Idesia polycarpa group and Dryopteris erythrosora group, while the Q. glauca community was subdivided into the Mercurialis leiocarpa group and Arachniodes aristata group. The T. nucifera species showed the highest level of importance in vegetation units 1 (Litsea japonicacommunity group-Torreya nucifera community-Idesia polycarpa group) and 2 (Litsea japonica community group-Torreya nucifera community-Dryopteris erythrosora group), whereas Q. glauca showed the highest level of importance in vegetation units 3 (Litsea japonica community group-Quercus glauca community-Mercurialis leiocarpa group) and 4 (Litsea japonica community group-Quercus glauca community-Arachniodes aristata group). In terms of the species diversity, vegetation units 1, 2, 3, and 4 had 2.866, 2.716, 2.222, and 2.326 species, respectively. These findings suggest that it is necessary to prepare a differentiated management plan for each vegetation unit.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.869-881
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• 2023

Purpose: This study aims to come up with improvement measures to improve the effectiveness of child safety measures. Method: The current status of child safety accidents was investigated and implications were deduced by analyzing major child safety measures by government department in the past. In addition, a perception survey was conducted on 1,000 people including children, guardians, and children's facility workers who are subject to child safety policies. Result: Regarding the safety of children's living space(environment), 35.3% of guardians answered that more than 1/3 of them were not safe. Both guardians(95.3%) and children's facility workers(89%) answered that there was the highest risk of 'traffic accidents', and the second risk factor was parents(carelessness of workers at children's facilities) and children's facility workers(careless of guardians at home). Looking at the risks by place, "road and sidewalk" was the most dangerous place and for child safety, guardians(64.3%) and workers (78.3%) both said that the role of "parent" is the most important. For improvements to prevent child safety accidents, the response rate of "strengthening safety management of road traffic facilities" is the most necessary with 75.8% for guardians and 65% for child use facilities. Conclusion: The reinforcement measures to strengthen the effectiveness of child safety measures are as follows. First, in order to ensure the continuity of child safety measures, it should be operated effectively so that those subject to the establishment of the Comprehensive Plan for Child Safety, which took effect in August 2022, can feel it. Second, in order to improve the sensitivity of children's policy targets, promotion measures that take into account the characteristics of each child safety field should be continuously strengthened. Third, it is necessary to expand safety infrastructure for each field to secure child safety. Fourth, it is necessary to strengthen safety education that can ensure safety for children themselves and to come up with detailed measures to make safety education for parents(guardians) mandatory.

• Journal of Life Science
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• v.33 no.12
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• pp.995-1001
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• 2023

This study investigated the effects of three music genres (classical, new age, and rock) on the stress levels of six Jeju crossbred horses (Jeju horse × Thoroughbred) in a horse stable. The horses were exposed to the three genres for seven days, and their stress levels were measured by analyzing physiological markers, including neurotransmitter (cortisol, β-endorphin, dopamine, serotonin, and oxytocin) plasma levels and creatine phosphokinase (CPK) and aldolase serum levels. The neurotransmitter analysis showed significant differences in cortisol levels between classical and new age music exposure. Dopamine levels decreased significantly only with new age exposure. Although there were no significant differences in β-endorphin levels between the three genres, β-endorphin levels decreased with increasing classical and new age music playback times and increased with increasing rock music playback times. There were no significant differences in serotonin levels between the three genres. Oxytocin levels decreased significantly with exposure to classical and rock music. The CPK and aldolase analyses showed that CPK levels decreased significantly only with exposure to new age music and increased after playback ended, while aldolase levels decreased significantly with classical and new age music exposure and increased after playback ended. These findings suggest that classical music and new age are the optimal music genres for the psychological stability of Jeju crossbred horses. Playing back an appropriate music genre could be used to improve breeding and promote the welfare of Jeju crossbred horses.

• Journal of Korea Water Resources Association
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• v.56 no.11
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• pp.751-764
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• 2023

Gangwon State is centered on the Taebaek Mountains with very different climate characteristics depending on the region, and localized heavy rainfall is a frequent occurrence. Heavy rain disasters have a short duration and high spatial and temporal variability, causing many casualties and property damage. In the last 10 years (2012~2021), the number of heavy rain disasters in Gangwon State was 28, with an average cost of 45.6 billion won. To reduce heavy rain disasters, it is necessary to establish a disaster management plan at the local level. In particular, the current criteria for heavy rain warnings are uniform and do not consider local characteristics. Therefore, this study aims to propose a heavy rainfall warning criteria that considers the threshold rainfall for the advisory areas located in Gangwon State. As a result of analyzing the representative value of threshold rainfall by advisory area, the Mean value was similar to the criteria for issuing a heavy rain warning, and it was selected as the criteria for a heavy rain warning in this study. The rainfall events of Typhoon Mitag in 2019, Typhoons Maysak and Haishen in 2020, and Typhoon Khanun in 2023 were applied as rainfall events to review the criteria for heavy rainfall warnings, as a result of Hit Rate accuracy verification, this study reflects the actual warning well with 72% in Gangneung Plain and 98% in Wonju. The criteria for heavy rain warnings in this study are the same as the crisis warning stages (Attention, Caution, Alert, and Danger), which are considered to be possible for preemptive rain disaster response. The results of this study are expected to complement the uniform decision-making system for responding to heavy rain disasters in the future and can be used as a basis for heavy rain warnings that consider disaster risk by region.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.4
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• pp.303-312
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• 2023

The determination of the oxidation states of metal elements in manganese nodules sheds light on the understanding of the formation mechanism of nodules, providing insights into the paleo-environmental conditions such as the redox potential of the aqueous system. This study aims to reveal the oxidation states and chemical bonding of manganese in the natural polymetallic nodules, utilizing conventional X-ray photoelectron spectroscopy (XPS). Specifically, shallow manganese nodules from the Siberian Arctic Sea, effectively recording mineralogical variations, were used in this study. Detailed analysis of XPS Mn 2p spectra showed changes in the manganese oxidation state from the center to the outer parts of the nodules. The central part of the nodules showed a higher Mn⁴⁺ content, approximately 67.9%, while the outermost part showed about 63% of Mn⁴⁺ due to an increase in the Mn³⁺+Mn²⁺. The decrease in the Mn oxidation state with the growth is consistent with the previously reported mineralogical variations from todorokite to birnessite with growth. Additionally, the O 1s spectra presented a predominance of Mn-O-H bonds in the outer layers compared to the center, suggesting hydration by water in the layered manganates of outer layers. The results of this study demonstrate that XPS can be directly applied to understand changes in paleo-environmental conditions such as the redox states during the growth of manganese nodules. Finally, future studies using high-resolution synchrotron-based XPS experiments could achieve details in oxidation states of manganese and trace metal elements.

• Korean Journal of Culture and Social Issue
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• v.8 no.1
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• pp.103-139
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• 2002

Korean society has significantly changed with the onset of a dramatic economic crisis in 1998. From 2000, however, the Korean economy has recovered and currently Korea is enjoying a similar standard of living and economic growth as the pre-1998 levels. This study is a follow-up analysis, comparing the results examining the success attribution of Korean students and adults in 2001 with the results obtained before the economic crisis in 1997. Using the indigenous psychological approach, this study compares the similarities and differences in Korean students and adults' attribution of their personal success before and after the economic crisis. A total of 988 participants, consisting of 481 primary, junior high, senior high and university students and 507 adults (236 fathers and 271 mothers of the students) completed the questionnaire developed by Kim and Park (1998). The results indicate that students perceived their academic achievement and adults perceived successful family life as their most proud achievement. Successful family life included items such as academic success of children, healthy development of their children, and harmonious family life. The person who provided the most significant support for students were parents and for adults, it was their spouse. For students, the importance of friends' social support increased during the high school years. In terms of type of social support, emotional support was reported to be the most important for both students and adults. As for the reason for their success, majority of students and men reported self-regulation and for women, supportive family environment was reported as being the most important. Comparing 2001 results with the 1997 results, the importance of family increased after the economic crisis. Even with the dramatic economic crisis, however, some of the underlying pattern remain strong (such as importance of academic achievement for students, family life for adults, the importance of social support, especially emotional social support from family members, and believing that self-regulation would lead to success). The similar pattern of results obtain before and after the economic crisis indicate that the above results reflect a fundamental values and belief system deeply imbedded in Korean mentality.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.4
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• pp.31-43
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• 2022

Startups are recognized as the vitality of the economy, and countries are competing to attract competitive overseas entrepreneurs and startups to their own startup ecosystem. In this global trend, entrepreneurs cross the border without hesitation, expecting abundant available resources and a startup friendly environment. Despite the increasing frequency of start-up migration between countries, studies related to this are very rare. Therefore, this study has chosen the cross-border migration of startups between countries as a research topic, and those who have been involved in the cross-border entrepreneurial migration to South Korea as a research sample. This study consists of two stages. The first research stage hires a Delphi method to collect expert opinions and find major factors related to the global startup migration. Drawing on the prior literature on the regional startup ecosystem at the national level, this stage is to conduct expert interviews in order to discover underlying factors and subfactors important for global migration of startups. The second stage measures the importance of the factors and subfactors using the AHP model. The priorities of factors and factors were identified hiring the overseas entrepreneurs who moved to Korea as the AHP survey samples. The results of this study suggest some interesting implications. First, a group of entrepreneurs with nomadic tendencies was found in the trend of global migration of entrepreneurs. They had already started their own businesses with the same business ideas in multiple countries before settling down in Korea. Second, important unique factors and subfactors in the context of global start-up migration were identified. A good example is the government's support package, including start-up visas. Third, it was possible to know the priority of the factors and subfactors that influence the global migration of startups This study is meaningful in that it preemptively conducted exploratory research focusing on a relatively new phenomenon of global startup migration, which recently catches attention in the global startup ecosystem. At the same time, it has a limitation in that it is difficult to generalize the meanings found in this study because the research was conducted based on the case of South Korea

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.1
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• pp.85-106
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• 2023

This study reviewed and derived the success factors of overseas agricultural startups and studied their integrated research model. Agricultural startups and general startups have in common that poor resources and infrastructure exist from a resource-based perspective after startup, but a differentiated approach from general startups is required due to the nature of the primary industry of agriculture. In this study, we approach the company internal factors (human resources/vision/distribution network capacity/capital capacity/cultivated crops/physical resources/farming technology, etc.) and external factors (agricultural infrastructure/laws/regulations/relationship with surrounding society, etc.) We tried to build a research model that can be integrated by focusing on various existing research models, success factors, and entrepreneurship. Through this, it is intended to present an integrated model that is practically helpful to business performance to entrepreneurs, business-related persons, and researchers who need an integrated understanding of agricultural startups at home and abroad. made for purpose In this paper, a standard model was established through three types (existing agricultural startup, small and medium-sized business startup, multinational company, and comprehensive approach) according to size and characteristics for modeling agricultural startup success factors. Through this, a total of 9 success factors (agricultural management, external environment, manager/founder characteristics, corporate identity, business management, organizational culture, infrastructure, commercialization capability, and sustainable growth) were derived. The implication of this study is that the success factors of agricultural startups were comprehensively presented based on 'entrepreneurship' for various domestic and foreign agricultural startup cases. By confirming the systematic categorization, a standard model for future agricultural startup success factors was presented, and as a result, a foundation was presented for systematic research and practical effectiveness of related research in the future.