• Atmosphere
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• v.34 no.3
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• pp.233-255
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• 2024

This study analyzed the distribution of Aerosol Robotic Network (AERONET) Version 3 Level 2.0 data, spanning over two decades, across South Korea and its six administrative regions (Seoul metropolitan area, Chungcheong, Jeolla, Gangwon, Gyeongsang, and Jeju). The research assessed long-term trends in aerosol optical depth (AOD) and mass concentration of particulate matter (i.e., PM₁₀ and PM_2.5), using data from the AERONET direct sun product and AirKorea, respectively. Additionally, eight aerosol types were identified using the scattering Ångström exponent and absorption Ångström exponent from the AERONET inversion product. The study further explored their domestic and regional distributions. Findings indicated that AERONET data were predominantly concentrated in the western regions of South Korea, including the Seoul metropolitan area, Chungcheong, and Jeolla, with a higher frequency of data in spring, thus demonstrating spatial and temporal heterogeneity. The annual average AOD exhibited a declining trend of -0.006 yr^-1. Similarly, PM₁₀ and PM_2.5 mass concentrations decreased by -1.324 ㎍ m^-3 yr^-1 and -1.335 ㎍ m^-3 yr^-1, respectively. These trends in AOD and PM₁₀ (PM_2.5) demonstrated positive correlations, with correlation coefficients of 0.674 (0.753) and statistically significant low p-values of 0.00058 (0.03), respectively. The analysis also revealed that aerosols in South Korea predominantly consisted of black carbon (BC) or BC-mixed types (84.09%), with a notable presence of smaller, less absorbent aerosol types (13.11%).

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.77-86
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• 2004

In this study, we applied the Bayesian Network for the case of the mode choice models using the Seoul metropolitan area's house trip survey Data. Sex and age were used lot the independent variables for the explanation or the mode choice, and the relationships between the mode choice and the travellers' social characteristics were identified by the Bayesian Network. Furthermore, trip and mode's characteristics such as time and fare were also used for independent variables and the mode choice models were developed. It was found that the Bayesian Network were useful tool to overcome the problems which were in the traditional mode choice models. In particular, the various transport policies could be evaluated in the very short time by the established relation-ships. It is expected that the Bayesian Network will be utilized as the important tools for the transport analysis.

• Journal of the Society of Disaster Information
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• v.20 no.1
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• pp.222-231
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• 2024

Purpose: The purpose of this study is to study how to activate the use of public transportation by identifying the main factors that reduce the use of public transportation due to external influences such as COVID-19 infectious diseases. Method: This study analyzed the connection between the traffic behavior and the characteristics of public transportation use in the metropolitan area changed by COVID-19 with COVID-19 indicators, and analyzed social and environmental factors affecting traffic. Results: It was analyzed that the traffic behavior in the metropolitan area moves from commercial areas to tourist resort areas, the number of COVID-19 deaths affects the use of public transportation, and the lower the deviation between population density, agricultural and forestry areas, and gender ratios due to social and environmental factors, the more significant differences are shown. Conclusion: In the future, it will be able to be activated as a basic analysis model for revitalizing the city's transportation system, regional bases, and various social and economic indicators, such as quarantine of public transportation and social distancing, and can be used as basic data for establishing public transport policy directions according to major influencing factors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.2
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• pp.115-127
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• 1991

In this paper. we dIscussed wIth the ISDN numberIng system of Korea 2digIt of NDC(National Destination Code)is assigned to the common carrier indenttification and an other the service network identification code as conbining the flIst and second dIgIt. The last ot NDC is applicable to for each area code. Resulty. we become 10 digit number for toll system vice 7 digit for local numbering. It is satisfactory to CCITT recommandtion and also. We has been suggested that existing network the mobile. pagget, FAX, TELEX and public networks are able to be connetcted to the ISDN. Near the 1994. we guess that it is fully occupied with 7 digit number to the metropolitan area to solve this problem, after divide to 3 part provincial area southern. nothem and mid-Korea. We suggested that special number system are reorganized with the new and existing service numbers plan. Although, we don't deal with the SA of ISDN numbering systems. Resultly, know that we are to design efficiently number system as 3 digit code for ISDN/NSN.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.189-199
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• 2019

The purpose of this study is to derive spatial area(preventive zone) where the movement of livestock vehicles occurs frequently. For this purpose, this study used 6 periods facility entrance data provided by KAHIS. This data was converted into vehicle movement data between livestock facilities and aggregated into administrative district units. The R-mode factor analysis was performed on the constructed OD data, and the region extracted by the same factor was judged as one region. The results of the analysis are summarized as follows. First, the factor analysis of 6 periods data showed 16 ~ 18 factors, and the derived factors explained 63 ~ 68% of the total variance. Second, based on the factors that were derived, Jeonam coastal area, Jeonnam area, Jeonbuk area, Chungnam coastal area, Gyeongnam area, northern Gyeongbuk area, Yeongnam costal area were found to be stable, with little change over time. On the other hand, Chungbuk area, Gangwon area, Seoul metropolitan area are relatively volatile areas. Third, 13 areas were derived by combining data from six periods.

• Journal of Korean Society on Water Environment
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• v.32 no.3
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• pp.310-317
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• 2016

It has been a big problem to estimate rainfall for the studies of mud-debris flows because the estimated rainfall from the nearest AWS (Automatic Weather Station) can tend to be quite inaccurate at individual sites. This study attempts to improve this problem through accurate rainfall depth estimation by applying an artificial neural network with radar rainfall data. For this, three models were made according to utilizing methodologies of rainfall data. The first model uses the nearest rainfall, observing the site from an ungauged site. The second uses only radar rainfall data and the third model integrates the above two models using both radar and observed rainfall at the sites around the ungauged site. This methodology was applied to the metropolitan area in Korea. It appeared as though the third model improved rainfall estimations by the largest margin. Therefore, the proposed methodology can be applied to forecast mud-debris flows in ungageed sites.

• Journal of Family Resource Management and Policy Review
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• v.13 no.1
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• pp.61-81
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• 2009

The purpose of this study was to investigate the policy demands of the family sector for work-family balance, with a focus on the child care and household labor provisions. For empirical analysis, data were collected from 197 dual-income families with at least one young child under age 10 in the metropolitan area via self-administered questionnaires. The major findings of this study were as follows. First, child care provisions for working mothers and fathers were insufficient and unfair, and the ratio of child care provisions offered by familial child care network was high. The characteristics of child care provisions for working parents were associated with family structure, working conditions, and demographic variables. Second, household labor provisions for working mothers and fathers were also insufficient and unfair, and the ratio of socialization was high. Third, the level of family satisfaction varied by the level of child care and household labor provisions, respectively, controlling family structure, working conditions, and demographic variables. The empirical results of the study provided policy implications for work-family balance.

• Korea Journal of Hospital Management
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• v.23 no.4
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• pp.26-39
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• 2018

Purposes: The purpose of this study is to analyze the issue of interest in patient medical service of small and medium hospitals using big data. Methods: The method of this study was implemented by data mining and social network using SNS big data. The analysis tool were extracted key keywords and analyzed correlation by using Textom, Ucinet6 and NetDraw program. Findings: In the results of frequency, the network-centered and closeness centrality analysis, It was shown that the government center is interested in the major explanations and evaluations of the technology, information, security, safety, cost and problems of small and medium hospitals, coping with infections, and actual involvement in bank settlement. And, were extracted care for disabilities such as pediatrics, dentistry, obstetrics and gynecology, dementia, nursing, the elderly, and rehabilitation. Practical Implications: Future studies will be more useful if analyzed the needs of customers for medical services in the metropolitan area and provinces may be different in the small and medium hospitals to be studied, further classification studies.

• Journal of Urban Science
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• v.10 no.1
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• pp.49-60
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• 2021

The purpose of this study is to analysis the impact on the inside of the new city when an incidents occurs on the Songdo International City connecting road, which has a limited access. The analysis data used KTDB's O/D and network data of the Seoul metropolitan area. In addition, the scenario composition applied a method of reducing the number of lanes on the road according to the situation of incidents, targeting bridges advancing from Songdo International City to the outside in the morning peak hours. The analysis method analyzed the traffic volume, total travel time, total travel kilometer, and route change in the new city based on the results of the traffic allocation model. As a result of the analysis, the range of influence was shown to two types. First, of the seven bridges, Aam 3, Aam 2, and Aam 1 were analyzed to have an impact only in some areas of the northwestern part of the new city. On the other hand, the remaining bridges were analyzed to affect the new city as a whole. The analysis results of this study are expected to be used as basic data to establish the scope of internal road network management when similar cases occur in the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.7
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• pp.963-971
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• 2022

Water pipeline network in local and metropolitan area is buried underground, by which it is hard to know the degree of pipe aging and leakage. In this study, assuming various sensor combinations installed in the water pipeline network, the optimal algorithm was derived by predicting the water flow rate and pressure through artificial intelligence algorithms such as linear regression and neuro fuzzy analysis to examine the possibility of detecting pipe leakage according to the data combination. In the case of leakage detection through water supply pressure prediction, Neuro fuzzy algorithm was superior to linear regression analysis. In case of leakage detection through water supply flow prediction, flow rate prediction using neuro fuzzy algorithm should be considered first. If flow meter for prediction don't exists, linear regression algorithm should be considered instead for pressure estimation.