• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.568-574
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• 2020

Recently, the installation of energy storage systems (ESSs) that have a range of functions, such as power stabilization of renewable energy sources, demand control, and frequency regulation, has been increasing annually. On the other hand, since the fire accident of ESS occurred at Gochang Power Test Center in August 2017, 29 fire accidents with significant property losses have occurred, including the Gyeongsan substation and Kunsan PV power plant. Because these fire accidents of ESS are arisen regardless of the season and capacity of ESS, an analysis of the fault characteristics in ESS is required to confirm the causes of the fire accidents accurately and ensure the safety of the ESS. This paper proposes the modeling of ESS using PSCAD/EMTDC S/W to identify the fault characteristics and ensure the safety of the ESS. From the simulation results of fault characteristics based on various scenarios, it is clear that the insulation of ESS may be breakdown due to the largely occurring CMV (common mode voltage). Furthermore, the CMV between the PCS and battery can be reduced, and the insulation breakdown of ESS can be prevented if an SPD (surge protect device) is installed in the battery and PCS sides, respectively.

• Journal of the Korean Society of Child Welfare
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• no.40
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• pp.139-166
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• 2012

The purpose of this study is to investigate the effects of poverty on the psychosocial adjustment of adolescents. Particularly, this study seeks to examine the mediating effects of neighborhood environments and parental depression. The 2008 'the Korean Youth General Survey' data were utilized. We analyzed data from 2,218 adolescents between the ages of 12 and 18 and their parents. We defined poverty as the income-to-needs ratio, and measured neighborhood environment using the degrees of neighborhoods' disorder, attachment, cohesion, and informal social control. Adolescents' externalizing and internalizing problem behaviors were used as indicators of adolescents' psycho-social adjustment. Structural equation modeling was utilized as the major analytic method. This study found that adolescents in low income families were more likely to reside in disadvantaged and dangerous neighborhoods. More importantly, the results revealed that psychosocial adjustment of the adolescents was indirectly influenced by poverty through the mediators, neighborhood environment and parental depression. Based on the results, we discussed policy and practice implications, including various interventions that may improve parental mental health and neighborhood environment of low income communities.

• Journal of the Korean earth science society
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• v.40 no.1
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• pp.86-106
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• 2019

The purpose of this study is to develop an astronomy education program reflecting astronomical thinking to be used at science museum and to investigate the effect of the program on the improvement of astronomical thinking ability of high school students. After selecting the components of astronomical thinking through literature studies, we developed an astronomy education program consisting of four stages: demonstration and observation, and question and thinking, support and group discussion, demonstration and assessment. In order to verify the effectiveness of the program, we conducted a covariance analysis on the pre- and post-tests of the experimental group and control group to examine the level of students' thinking before and after using the program in teaching and learning. As a result, it was confirmed that the astronomy education program reflecting astronomical thinking was effective in promoting students' astronomical thinking ability. In particular, this program was effective in enhancing the ability of modeling by reconstructing the observed astronomical phenomenon from the viewpoint of the universe with respect to spatial thinking in the astronomy domain. It was also effective to improve the ability of organizing the system by grasping the relationship between the elements constituting the astronomical system in relation to the system thinking in the astronomy domain. This study is significant in suggesting a specific teaching and learning program to develop students' astronomical thinking.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.6
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• pp.47-60
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• 2021

Since the outbreak of COVID-19 in 2019, the pandemic has been prolonged. This study compares and analyzes the degree of social media usage, the information type of posts (infectious disease information, promote action, psychological communication), and the level of user engagement in conducting crisis communication by country. We conduct text analysis by collecting information on Facebook and YouTube posts from January 2020 to March 2021 of disease control and prevention agencies in Korea, US, UK, and EU. As a result, the use of social media in Korea and US is higher than of the UK and EU, and all four countries are using social media as a means to provide infectious disease information and to promote action. Although social media can be a means to reach the public psychologically, such as sympathy and respect, there are no posts of psychological communication type on social media in countries other than the US. User engagement with posts is highest in the promotion action type. This study can help define the importance and role of social media in establishing an infectious disease crisis communication strategy.

• Journal of the Society of Disaster Information
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• v.18 no.2
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• pp.306-313
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• 2022

Purpose: The purpose of this study is suggested to improve upon current existing methods of ammonia chemical accident prevention and damage reduction. Method: Ammonia is one of the most common toxic substances that causes frequent chemical accidents. And it was selected as leakage materials according to statistics on chemical accident. Based on actual cases of chemical accidents, CARIS modeling was used to compare the damage impact range of Ammonia and HCl and Cl. Also, find out problems with the current systems. Result: As a result of find out the range of accident influence that spreads to the surroundings when an ammonia chemical accident, it was longer than the range of influence of hydrochloric acid and shorter than that of chlorine. In addition, it was found that when chemical accident by ammonia, hydrochloric acid, or chlorine, there are apartments and schools, which can have an effect. Conclusion: It is decided that it is necessary to determine whether or not chemical accident prevention management plans and statistical investigations are submitted for workplaces dealing with ammonia, and detailed guidelines and reviews are necessary. In addition, it is judged that it is necessary to establish a DB for ammonia handling plants, and it is considered that information sharing and joint inspection among related organizations should be pursued.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.877-886
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• 2022

This study was carried out to analyze how the flow and water quality of the Sangsa Lake (juam control basin) change according to future climate change and what countermeasures are needed. Aquatic Ecosystem Model) was used in conjunction. As climate change scenarios, RCP (Representative Concentration Pathways) 4.5 and RCP 8.5 scenarios of AR5 (5th Assessment Report) according to the Intergovernmental Panel on Climate Change (IPCC) were used. For the climate change scenario, detailed data on the Sangsa Lake basin were used by the Korea Meteorological Administration, and after being evaluated as a correction and verification process for the 10-year period from 2012 to 2021, the present, 2025-2036, 2045- The summer period from June to August and the winter period from December to February were analyzed separately for each year by dividing it into 2056 and 2075-2086. RCP 8.5 was higher than RCP 4.5 as an arithmetic mean for the flow rate of the watershed of the superior lake for the entire simulation period, and TN and TP also showed a tendency to be higher at RCP 4.5. However, in RCP 8.5, the outflow of pollutants decreased during the dry season and the outflow of pollutants increased during the summer, indicating that the annual pollutant outflow was concentrated during the flood season, and it is analyzed that countermeasures are needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.143-150
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• 2018

Periodic and systemic disaster management has become more important than ever owing to the recent continuous occurrence of disasters, such as fires, earthquakes, and flooding. This management goes beyond simple disaster preparedness, which was introduced minimally under the existing legal system. For effective disaster management, facilities should be managed through regular maintenance on a daily basis, and in the case of an emergency, intuitive and accurate communication is essential regarding the situation and purpose. BIM manages the entire building property data using the effective 3D visualization model, so it can be used for various management purposes from design to facility maintenance. In this study, through an expert survey on the use of services in a BIM-based integrated disaster information system, the available areas of BIM data were organized in terms of facility information management, 3D visualization, and disaster control. Later, through the use service and DB definition within the BIM-based disaster integration information system, the main facilities monitoring and response services based on BIM and BIM-based spatial management service are proposed. Based on this study, it is hoped that the BIM-based application service functions within the system will be implemented to enable an effective system response.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.3
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• pp.166-173
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• 2008

Recently, problem of earth environment being attended with international issue, people are concerned about the environmentally-friendly and renewable biomass energy. Especially, the forest biomass is more important because Korea have to control carbon footprint for Kyoto Protocol and Convention on Climate Change. In case of Korea, forest area covers the land about 2/3 of all country. It is needed that more economical and efficient method to estimate the biomass by remote sensing data which include wide coverage and is progressed by one-step. In this study, we estimate forest biomass with LiDAR data and aerial photograph. Three biomass equation is used and estimate mean biomass of single tree and entire biomass in plots. The results are compared with field data. $R^2$ of the mean biomass of single tree is greater than 0.8 and that of entire biomass in plots is greater than 0.65. In conclusion, the method using remote sensing data is verified more economical and efficient than previous field data method.

• Archives of design research
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• v.17 no.3
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• pp.133-146
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• 2004

Diagrams have been deeply and widely used for supporting effective communication relating to design information and knowledge in most design fields. The results show that their role expands to "developmental design material" increasing the principle and method of design process. It's recent trend that Digital-Diagrams are aggressively used in multimedia design fields such as web contents, interactive movies and DVD Titles in order to support user's information understanding more effectively and to stimulate user's participation in information acquiring process. This study aims to clarify the essence of digital diagram corresponding to infographic material in multimedia design and application of multimedia contents development process . This study purpose leads to argue the substance of Digital-Diagrams as one of infographic types and identity of Digital-Diagrams which is relatively compared to existing Diagrams. Eventually, this study examines the application issues of Digital-Diagrams in multimedia design process. Regarding the identity of Digital-Diagrams, they are functionally utilized depending on hypertext based on language forms and interactivity based on graphical forms as core attributes. Therefore, they semantically enlarge user s information understanding by segmenting hierarchy of information expression and rather support user s acquisition of information control ability. Relating to multimedia design process, Digital-Diagrams are used by information designers and navigation designers as method for ‘modeling for realization based on information acquisition support for information-users. Especially, the study results show that the applications of Digital-Diagrams are performed for information representing methods for information designers and embodiment of useful functional factors of interface for navigation designersgation designers.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.79-91
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• 2020

Accurate assessment of greenhouse gas emissions is a cornerstone of every climate change response study, and reliable assessment of greenhouse gas emission data is being used as a practical basis for the entire climate change prediction and modeling studies. Essential, fundamental technologies for estimating greenhouse gas emissions include an on-site monitoring technology, an evaluation methodology of uncertainty in emission factors, and a verification technology for reductions. The closed chamber method is being commonly used to measure gas fluxes between soil-vegetation and atmosphere. This method has the advantages of being simple, easily available and economical. This study presented the technical bases of the closed chamber method for measuring methane fluxes from a rice paddy. The methane fluxes from rice paddies occupy the largest portion of a single source of greenhouse gas in the agricultural field. We reviewed the international and the domestic studies on automated chamber monitoring systems that have been developed from manually operated chambers. Based on this review, we discussed scientific concerns on chamber methods with a particular focus on quality control for improving measurement reliability of field data.