• Journal of Wetlands Research
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• v.26 no.2
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• pp.147-159
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• 2024

Lack of streamflow observations makes model calibration difficult and limits model performance improvement. Satellite-based remote sensing products offer a new alternative as they can be actively utilized to obtain hydrological data. Recently, several studies have shown that artificial intelligence-based solutions are more appropriate than traditional conceptual and physical models. In this study, a data-driven approach combining various recurrent neural networks and decision tree-based algorithms is proposed, and the utilization of satellite remote sensing information for AI training is investigated. The satellite imagery used in this study is from MODIS and SMAP. The proposed approach is validated using publicly available data from 25 watersheds. Inspired by the traditional regionalization approach, a strategy is adopted to learn one data-driven model by integrating data from all basins, and the potential of the proposed approach is evaluated by using a leave-one-out cross-validation regionalization setting to predict streamflow from different basins with one model. The GRU + Light GBM model was found to be a suitable model combination for target basins and showed good streamflow prediction performance in ungauged basins (The average model efficiency coefficient for predicting daily streamflow in 25 ungauged basins is 0.7187) except for the period when streamflow is very small. The influence of satellite remote sensing information was found to be up to 10%, with the additional application of satellite information having a greater impact on streamflow prediction during low or dry seasons than during wet or normal seasons.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.4
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• pp.29-38
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• 2016

The maps produced by the NGII(geographical information institute) are composed of 1/1,000, 1/2,500, 1/5,000 large scale maps, 1/25,000, 1/50,000 and smaller scale maps. 1/1,000 digital map, as the most large-scale digital map made by the NGII, has been constructed with the beginning of NGIS(national geographic information System) Project in 1995. However, 1/1000 digital maps have been not produced by the fundamental survey on the basis of systematic planning at the national level, but a lot of parts have been constructed by the public survey for the purpose of the fiscal year of the local governments. Also, these maps have been not regularly updated because of big budget. In this study, we investigated problems related to the construction status, system, and area, and suggested plans that can improve these problems. As the improvement plan, we proposed a nationwide three regionalization for short-term modification and long-term regular update, reset of core downtown boundaries based on topographical features, diversification of budget execution method and an improved execution system.

• Journal of Korea Water Resources Association
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• v.37 no.12
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• pp.1019-1032
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• 2004

Flood frequency estimate is an essential index for determining the scale of small and middle hydraulic structure. However, this flood quantity could not be estimated directly for practical design purpose due to the lack of available flood data, and indirect method like design rainfall-runoff method have been used for the estimation of design flood. To give the good explain for design flood estimates, regional flood frequency analysis was performed by flood index method in this study. First, annual maximum series were constructed by using the collected data which covers from Japanese imperialism period to 1999. Wakeby distribution recommended by WMO(1989) was used for regional flood frequency analysis and L-moment method by Hosking (1990) was used for parameter estimation. For the homogeneity of region, the discordance and heterogeneity test by Hosking and Wallis(1993) was carried for 4 major watersheds in Korea. Physical independent variable correlated with index flood was watershed area. The relationship between specific discharge and watershed area showed a type of power function, i.e. the specific discharge decreases as watershed area increases. So flood quantity according to watershed area and return period was presented for each watershed(Han rivet, Nakdong river, Geum river and Youngsan/Seomjin river) by using this relation type. This result was also compared with the result of point frequency analysis and its regionalization. It was shown that the dam construction couldn't largely affect the variation of peak flood. The property of this study was also examined by comparison with previous studies.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.252-263
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• 2008

This study was conducted to derive the optimal regionalization of the precipitation data which can be classified on the basis of climatologically and geographically homogeneous regions all over the regions except Cheju and Ulreung islands in Korea. A total of 65 rain gauges were used to regional analysis of precipitation. Annual maximum series for the consecutive durations of 1, 3, 6, 12, 24, 36, 48 and 72hr were used for various statistical analyses. K-means clustering mettled is used to identify homogeneous regions all over the regions. Five homogeneous regions for the precipitation were classified by the K-means clustering. Using the L-moment ratios and Kolmogorov-Smirnov test, the underlying regional probability distribution was identified to be the generalized extreme value (GEV) distribution among applied distributions. The regional and at-site parameters of the generalized extreme value distribution were estimated by the linear combination of the probability weighted moments, L-moment. The regional and at-site analysis for the design rainfall were tested by Monte Carlo simulation. Relative root-mean-square error (RRMSE), relative bias (RBIAS) and relative reduction (RR) in RRMSE were computed and compared with those resulting from at-site Monte Carlo simulation. All show that the regional analysis procedure can substantially reduce the RRMSE, RBIAS and RR in RRMSE in the prediction of design rainfall. Consequently, optimal design rainfalls following the regions and consecutive durations were derived by the regional frequency analysis.

• Journal of the Korean association of regional geographers
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• v.8 no.2
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• pp.170-183
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• 2002

Recently it is supposed to be a shift to regional geography. To understand the emergence of the new regional geography, It must be remarked that the progress of capitalist production and consumption change our conceptional apparatus such as representation of space. Region is one of the important mode of representations of space and time. In the Fordist capitalism of 20th century, development is regarded as diffusion of capitalist expansion of western worlds. State must support capitalist growth through regional policies which include constructing of infrastructure and regionalization of spatial division of labour. The regional development theories contributed as ideology and policy tools for state intervention. The region was simply one of the most logical classification tools of organizing geographical informations. In the theories of regional development, the concept of region was reduced to the formal unit of classification. As the transition from Fordism to flexible accumulation, the region is again acquiring its 'identity' and 'authenticity'. In this tendency of the revival of region, it is expected that good achievement could be made in the field of regional geography through relevant research methods. It is also believed one of the available means are historical approaches to the cultural and ecological regions. The historical approaches to cultural and ecological regions are not only correspondent with cultural development strategies of local governments, but also could convey regional identities through both narrativization of place and aestheticization of landscape.

• Journal of the Korean association of regional geographers
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• v.8 no.2
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• pp.184-198
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• 2002

Since the mid-1980s there has been an intensive debate on a regional geography in abroad, and its renaissance has been widely expressed. Under the influences of these academic circumstances, many Korean scholars have tried to introduce this trend and at the same time to propose new development lines of the Korean geography with a critical perspective. However, the empirical study of Korean regional geography including area studies is characterized by a quantitative deficit on the one hand and by its peripheral position on the other. The main reasons of this marginalization of Korean regional geography that we can find include a undifferentiated import of new systematic/nomothetic geography in the 1960s and 1970s, a historical interruption with a tradition of old Korean geography, and the practical difficulties of regional geographical approach itself. Now we face with the fundamental changes including globalization/regionalization and an increasing actual demand for the information on different scales of space and place. In order to cope with these challenges, we inevitably need to revitalize various forms and modem characteristics of regional geographical approaches and try to reexamine the basic concepts, methods, and frameworks of regional geography.

• Journal of the Korean Geographical Society
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• v.50 no.3
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• pp.325-338
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• 2015

Telemedicine, which gives or receives medical information via ICT (information and communication technology), is regarded as innovation in a medical field and its application is various according to offline conditions. For example, the utilization of telemedicine in Korea is unfair because of the administrative discretion, which is the basic unit of telemedicine for its practical operation, in spite of the same diagnostic area. With this mind, this study investigates the cause of regional differences of telemedicine through a case of Kangwon province. Furthermore, the crucial matter is that regional differences of telemedicine are associated with digital divide; therefore, this research considers digital divide triggered by telemedicine. The core results are as follows. First, there are little measures such as increase of the staff, economic compensation for public officials, education of telemedicine facilities; accordingly, only regions, where can accept these insufficient conditions, manage the telemedicine system. Second, the interesting of a mayor or a governor and a head of a health center as a highest decision maker has something to do with different utilization of telemedicine. Third, public health doctors play a role as practical operators in telemedicine, but their stance is skeptic about telemedicine somewhat because of the relationship with the medical association opposing the implementation of telemedicine, unimproved regional health care condition, etc. Forth, it seems that the digital divide caused by the regional differences of the present telemedicine utilization does not led to tangible results and is not turned to another disparity so far, the proper measures are required considering that various health care services based on telemedicine will be extended.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.390-403
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• 1988

The objectives of the study were to provide the basic informations needed in the development of balanced medical services throughout the nation. As the national health care system was expanding rapidly along with the economic growth, quantitative re-evaluation of the system is of great need. For that reason, characteristics of the admitted patients were analyzed for the case-mix and patients' flow within and through regions. Materials were 421,530 cases of inpatients, who were reported through Korea Medical Insurance Corporation(KMIC) for insurance claim, during the period of March 1, 1985 through February 28, 1987. Korean Diagnosis Related Groups(K-DRGs) classification system was adopted for the study of case-mix and 189 cities and counties were classified into 5 district groups by factor analysis results of K-DRGS. The major findings of this study were as follows ; 1) Factor analysis of case-mix, employing K-DRG system, revealed 5 distinct funtional district groups. Group A(18 districts) was prominent for tertiary medical care. In group B(36 districts), rather simple procedures were prevalent. Group C(26 districts) was distinctive for the medical care of well organized internal medicine practices with qualified clinical laboratories. Group D(17 districts) was characterized by relatively high balanced medical care. Group E (92 districts) was with very low level of medical care. 2) Analysis of the case-flow through the districts showed 3 types of flow patterns : inflow, outflow, and balanced types. Inflow type of case-flow was found in Group A, C and D while Group B and E showed outflow type. Inflow was most prominent in Group A and Group E was of typical outflow type. Group B was consistently the outflow type except for Major Diagnostic Category XX regardless of the disease treaters, but Group C and D were inflow or outflow types according to the disease tracers.

• Journal of the Korean Geographical Society
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• v.38 no.4
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• pp.575-590
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• 2003

It was the landscape phase that social relations were extended by production of landscapes during the 16C～17C. Core lineage groups in study area had extended socio-spatial nexus through making of the landscape of ‘authority-ostentation’(권력-과시형 경관) and of ‘kindness-civilization’(시혜ㆍ교화형 경관). Therefore they could gain a result that their power and authority took root in community perfectly. In the case of the Kims of Kwangsan(광산김씨), the first landscape of ‘kindness-civilization’ was Jungheodang(the learning room Jungheo), and next it was built Yangsungdang(the learning room Yangsung), and Imlijung(the pavilion Imli). Through this landscape production, the consciousness of scholastic genealogy was born, and this genealogy consciousness could be deepened and extended in regional scale. One more important feature in this phase is the point that the Kims of Kwangsan in Yeonsan area and the Songs of Unjin(은진송씨) in Hoiduk area could unite socially by the landscape production of ‘kindness-civilization type’ becoming intermediation. And these social union, that is to say, it do connote enlargement of the territoriality. It tells that community of ‘regional’ scale was formed by of core lineage groups of ‘local’ uniting each other.

• Journal of Korea Water Resources Association
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• v.40 no.3
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• pp.205-214
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• 2007

The objective of this study is to generate the regional scale runoff scenarios by using IPCC SRES A2 climate change scenario for analyzing the spatial variation of water resources in Korea. The PRMS model was adopted to simulate long-term stream discharge. To estimate the PRMS model parameters on each sub-basin, the streamflow data at 6 dam sites and Rosenbrock's scheme are used for model parameter calibration and those parameters are translated to ungauged catchments by regionalization method. The other 3 dam sites are selected for the verification of the adequateness of regionalized model parameters in ungagued catchments. The statistical results show that the simulated flows by using regionalized parameters well agree with observed ones. The generated runoff scenarios by climate change are compared with observed data on 4 dam sites for the reference period. The consequences show that the selection of climate station for generating climate scenario affects the reliability of climate scenario at sub-basin. The comparison results of the stream flows between the 30-year baseline period (1971-2000) and future 90-year (2001-2030, 2031-2060, 2061-2090) show that the long-term mean annual runoff in the Han River has increasing trend, while the Nakdong, the Gum, the Youngsan and the Sumjin Rivers have decreasing trend.