• Journal of Korea Water Resources Association
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• v.53 no.spc1
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• pp.755-764
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• 2020

In South Korea, 850 standard watersheds and 7,807 KRF catchment areas have been used as basic maps for water resources policy establishment, however it becomes necessary to set up new standard maps with a more appropriate scale for the integrated managements of surface water-groundwater as well as water quantity-quality in the era of integrated water management. Since groundwater has a slow flow velocity and also has 3-D flow properties compared to surface water, the sub-catchment size is more effective than the regional watershed for the evaluation of surface water-groundwater interaction. The KRF catchment area, which has averagely a smaller area than the standard watershed, is similar to the sub-catchment area that generally includes the first-order or second-order tributaries. Some KRF catchment areas, which are based on the surface reach, are too small or large in a wide plain or high mountain area. Therefore, it is necessary to revise the existing KRF area if being used as a unit area for integrated management of surface-water and groundwater. A unit watershed with a KRF area of about 5 to 15 ㎢ can be effective as a basic unit for water management of local government considering a tributary composition and the location of groundwater wells, and as well it can be used as a basic tool for water demand-supply evaluation, hydrological observation system establishment, judgment of groundwater permission through a total quantity management system, pollution assessment, and prioritizing water policy, and etc.

• Korean Journal of Medicinal Crop Science
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• v.10 no.1
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• pp.41-45
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• 2002

An efficient and reproducible procedure for the large scale propagation of Hovenia dulcis Thunb. is described. Shoot primodia emerging from the leaf surface was induced from MS medium supplemented with NAA. Stem cuttings were suitable explants for multiple shoot proliferation. They produced axillary shoots which branched repeatedly, yielding an average of 7 shoots per explants after 4 weeks in culture, when cultured on a woody plant medium (WPM) containing 0.1mg/l BA and 0.1mg/l NAA. Stem, leaf and root segments from axenic seedlings were used as explant source to induce somatic embryogenesis. A high frequency of somatic embryos were induced directly from leaf in MS medium with NAA, 2,4-D and in medium containing NAA, 2,4-D with BA. Somatic embryos were germinated in MS medium supplemented with 1mg/ l $GA_3$. Somatic embryos proliferated secondary somatic embryos rapidly after transfer to MS medium supplemented with 1mg/ l kinetin, 1mg/ l $GA_3$ and 2% dextrose.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.529-537
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• 2014

To establish a foundation to objectively interpret Chosun history, we construct people network of the Chosun dynasty. The network shows scale free network properties as if most social networks do. The people network is composed of 1,379 nodes and 3,874 links and its diameter is 14. To analysis of the network dynamics, whole network that is composed of 27 king networks were constructed by adding the first king, Taejo network to the second king, Jeongjong network and then continuously adding the next king networks. Interestingly, betweenness and closeness centralities were gradually decreased but stress centrality was drastically increased. These results indicate that information flow is gradually slowing and hub node position is more centrally oriented as growing the network. To elucidate key persons from the network, k-core and MCODE algorithms that can extract core or module structures from whole network were employed. It is a possible to obtain new insight and hidden information by analyzing network dynamics. Due to lack of the dynamic interacting data, there is a limit for network dynamic research. In spite of using concise data, this research provides us a possibility that annals of the Chosun dynasty are very useful historical data for analyzing network dynamics.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.582-591
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• 2015

Late-Koryeo people networks were constructed from four different history books that were written by various historic aspects in the period from king Kongmin to the final king of the Koryeo, Kongyang. All networks constructed in this study show scale free network properties as if most social networks do. Tajo-sillok preface is one of subjectively written history book that described personal history of the Lee Seong-gye and his ancestors. It is confirmed that the book is one of the most biased-written history books through network study. Jeong Do-jeon known as a Chosun dynasty projector is not greatly contributed for founding of a Chosun dynasty in network study and various historical documents as well. In this network study, we provide objective historical information in the historical situations of the late-Koryeo and during establishment procedure of Chosun dynasty. Hub nodes in network is denoted highly linked nodes, called degree. Stress centrality is a unit to measure positional importancy in the network. If we employ two factors, degree and stress centrality to determine hub node, it represents high connectivity and importancy as well. As comparing values of the degree and stress centrality, we elucidate more objective historical facts from late-Koryeo situations in this study. If we further develop and employ a new algorithm that is considered both degree and stress centrality, it is a very useful tool for determining hub node.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.1
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• pp.215-233
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• 2014

Seoul is an ancient city with a long history but there is hesitancy over referring to as a historic city due to the lack of traceable historic urban landscape elements which resulted from numerous invasions and general destruction. From a diachronic perspective, the nature which was survived the influence of development, could be the key element that links the past with the city's radically changed image in modern times. Although "old big trees" may be not a dominant influence with regards to the historical authenticity of the city, they are objects which contribute towards the historical authenticity by providing a sense of place in terms of connected narratives, as well as their natural image. However, the protection policy for an "old big tree" would place too much emphasis on the aspect of the ecological value rather than its cultural value. Generally, trees have been protected by installing a fence and a signboard around them as well as receiving additional care. However, it is difficult to find that surrounding space around the "law-protected tree" is connected with its original historical and cultural values. Even though the space around trees are no longer utilized in the same way as was so in the past, they still have high-potential in terms of cultural utilization. Therefore, the subject of this study is the "old big tree" as a natural object which contributed to the historical authenticity of Seoul. The current status of these "old big trees", aged between 100 and 800 years old, currently indicate that there are 215 trees designated as "law-protected tree" by the Seoul metropolitan government. This study aims to investigate the status of protection and utilization of the existing "law-protected trees" in the city of Seoul and find a way to increase both ecological preservation and cultural utilization for the high-potential "law-protected trees" within the city itself. In order to achieve this, previously researched papers shall be reviewed and surveyed pertaining to present usage patterns of the 215 "law-protected trees". In addition, five cases have been reviewed which focus on a few of utilizing the "protected trees" and their surrounding spaces. The results of the research indicate that 21 "old big trees" have high-potential in terms of cultural utilization as well as ecological value. However, it was revealed that there are limitations to pursue the value of preservation and utilization simultaneously throughout current regimental management. In order to cope with the current situation, it is pointed out that management facilities should be designed and installed by creative and flexible methods of organizing with consideration to the surrounding space and context. Even though in the case where there may not be a connecting history or legendary stories, the "old big trees" can serve as the fundamental features of small scale parks -dependent on their location, condition and environment- which will be of value to the local communities. This study could serve as a practical reference for the management and utilization of "old big trees" nationwide with numbers reaching 12,300 besides the city of Seoul.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.2
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• pp.86-100
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• 2015

Cloud computing is a computing term that evolved in the late 2000s, based on utility and consumption of computer resources. Google say that "Cloud computing involves deploying groups of remote servers and software networks that allow different kinds of data sources be uploaded for real time processing to generate computing results without the need to store processed data on the cloud. Cloud computing relies on sharing of resources to achieve coherence and economies of scale, similar to a utility (like the electricity grid) over a network. At the foundation of cloud computing is the broader concept of converged infrastructure and shared services. Cloud computing, or in simpler shorthand just "the cloud", also focuses on maximizing the effectiveness of the shared resources." The cloud service is a smart and/or intelligent service to save private files in any device, anytime, anywhere. Dropbox, OAuth, PAClous are required that the accumulated user's data are archives with cloud service. Currently we suggest an implementation technique to process many tasks to the cloud server with a thread pooling. Thread pooling is one of efficient implementating technique for client and service environment. In this paper, to present the implementation technique we suggest three diagrams in the consideration of software engineering.

• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.41-50
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• 2010

This study presented a model that can enable a reliability analysis for the repair and replacement cycle of a building by using background repair and replacement data and expert opinion as foundation data and applying Monte Carlo Simulation. The presented model offers the time of the repair and replacement of building elements for the period of a year, and supports the prediction of repair and replacement and expenses demand in advance while planning the maintenance of a building. In addition, the model will significantly reduce the risks to the building owner with regard to maintenance decisions. In addition, when a person in charge of the maintenance of large-scale building assets is having difficulties making decisions regarding the repair and replacement of existing building elements due to a lack of background data to support a long-term policy on the repair and replacement requirements, an engineering solution that can ensure the adequacy of this is provided. In summary, it can be largely divided into three study results. First, a method of estimating the repair and replacement cycle that can deal with the development of a construction system was developed. Second, a probabilistic methodology that can quantify the risk of the repair and replacement cycle was proposed. Third, the proposed model can be used as a means of supporting designer and constructor in making decisions for the life cycle plan of a building during a construction project.

• Journal of Preventive Medicine and Public Health
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• v.52 no.6
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• pp.405-415
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• 2019

Objectives: The aim of this study was to evaluate the associations of frailty with perceived neighborhood walkability and environmental pollution among community-dwelling older adults in rural areas. Methods: The participants were 808 community-dwelling men and women aged 65 years and older in 2 rural towns. Comprehensive information, including demographics, socioeconomic status, grip strength, polypharmacy, perceived neighborhood environment (specifically, walkability and environmental pollution), and frailty, was collected from participants using face-to-face interviews conducted between June and August 2018. Perceived neighborhood walkability was measured using 20 items that were selected and revised from the Neighborhood Environment Walkability Scale, the Neighborhood Walkability Checklist from the National Heart Foundation of Australia, and the Physical Activity Neighborhood Environment Survey. The Kaigo-Yobo Checklist was used to assess participants' frailty. Results: The overall prevalence of frailty in this community-dwelling population was 35.5%. Sex, age, cohabitation status, educational attainment, employment status, grip strength, and polypharmacy were significantly associated with frailty. In the logistic regression analysis, frailty was associated with low perceived neighborhood walkability (adjusted odds ratio [aOR], 0.881; 95% confidence interval [CI], 0.833 to 0.932; p<0.001) and severe perceived neighborhood environmental pollution (aOR, 1.052; 95% CI, 1.017 to 1.087; p=0.003) after adjusting for sex, age, cohabitation status, educational attainment, employment status, monthly income, grip strength, and polypharmacy. Conclusions: More studies are warranted to establish causal relationships between walkability and environmental pollution and frailty.

• 한국노년학
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• v.38 no.4
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• pp.999-1013
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• 2018

This study examined the effect of the perception of age-friendly environment on perceived social bonding. In particular, this study focused on the mediating effects of perception of age-integration between perception of age-friendly environment and perceived social bonding. The data were analyzed using the '2017 Ages Integration Survey' conducted by the Korea Research Foundation(SSK). A total of 997 adults from 20 to 86 ears of age were participated in this study. The perception of age-friendly environment was measured using the age-friendly city guidelines set out by WHO and perception of age-integration was measured using questions that asked about age flexibility and age diversity. Also, the social capital scale was used to measure perception of social bonding. In order to increase the reliability of the analysis results, age, gender, educational achievement and residential area were controlled. Structural Equation Modeling approach was employed to answer the research questions. The results are following. First, perception of age-friendly environment was significantly associated with perceived social bonding in a positive direction, controlling for age, gender, educational achievement and residential area. Second, perception of age-integration partially mediated the relationship between perception age-friendly environment and perceived social bonding controlling for covariates. Based on these findings, this study proposes political and practical intervention strategies to promote age-friendly environment and age-integration.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.507-514
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• 2018

TSI (TPI-Slope Index) which is the combination of TPI (Topographic Position Index) and slope was newly proposed for landslide and applied to a landslide susceptibility model. To do this, we first compared the TPIs with various scale factors and found that TPI350 was the best fit for the study area. TPI350 was combined with slope to create TSI. TSI was evaluated using logistic regression. The evaluation showed that TSI can be used as a landslide factor. Then a logistic regression model was developed to assess the landslide susceptibility by adding other topographic factors, geological factors, and forestial factors. For this, landslide-related factors that can be extracted from DEM (Digital Elevation Model), soil map, and forest type map were collected. We checked these factors and excluded those that were highly correlated with other factors or not significant. After these processes, 8 factors of TSI, elevation, slope length, slope aspect, effective soil depth, tree age, tree density, and tree type were selected to be entered into the regression analysis as independent variables. Three models through three variable selection methods of forward selection, backward elimination, and enter method were built and evaluated. Selected variables in the three models were slightly different, but in common, effective soil depth, tree density, and TSI was most significant.