• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.991-998
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• 2022

The purpose of this study is to develop GPU (Graphics Processing Unit) acceleration technique for 2-dimensional model and to assess the effectiveness for high resolution flood simulation in wide area In this study, GPU acceleration technique was implemented in the G2D (Grid based 2-Dimensional land surface flood model) model, using implicit scheme and uniform square grid, by using CUDA. The technique was applied to flood simulation in Jinju-si. The spatial resolution of the simulation domain is 10 m × 10 m, and the number of cells to calculate is 5,090,611. Flood period by typhoon Mitag, December 2019, was simulated. Rainfall radar data was applied to source term and measured discharge of Namgang-Dam (Ilryu-moon) and measured stream flow of Jinju-si (Oksan-gyo) were applied to boundary conditions. From this study, 2-dimensional flood model could be implemented to reproduce the measured water level in Nam-gang (Riv.). The results of GPU acceleration technique showed more faster flood simulation than the serial and parallel simulation using CPU (Central Processing Unit). This study can contribute to the study of developing GPU acceleration technique for 2-dimensional flood model using implicit scheme and simulating land surface flood in wide area.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.176-177
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• 2000

대도시의 국소지역인 도심지 도로변 양측은 빌딩에 의해 둘러싸여 있어 canyon으로 비유되어 street canyon이라고 하며 도로에 관한 선행연구는 도로변에 관한 것과 street canyon에 관한 것 그리고 두 경우를 전부 포함하는 경우로 분류할 수 있다. 도로변에 있어서 자동차 배출가스의 확산 예측에 관한 연구는 가우시안형 해석해 모형이 가장 많고 그 외 비가우시안형 해석해 모형, 반경험식 모형, 수치해 모형으로 분류되고 있다. (중략)

• Journal of the Korean Regional Science Association
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• v.33 no.3
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• pp.21-30
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• 2017

The purpose of this study is to analyze the effect of urban characteristics on regional population and to suggest policy implications based on the analysis results. For this purpose, this study used spatial econometrics analysis(SAR, SEM, SAC) using data on 122 eup-myon-dong areas in Incheon Metropolitan City. As a result of the analysis, First, in terms of spatial, population density showed positive (+) effect while employment density has negative (-) effect. Also, the increase in the number of tertiary industries and workers in the industry has a positive (+) effect. Second, in terms of housing, the apartment ratio showed positive (+) effect and the increase of low-rise deteriorated housing has negative (-) effect. Third, the increase in educational facilities and urban parks showed positive (+) effect on population. In conclusion several policy implications for urban management found through this analysis are discussed.

• Journal of Korean Society of Transportation
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• v.36 no.3
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• pp.195-202
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• 2018

Jobs-housing balance refers to the situations where the employment (work) and housing (house) opportunity are coincided in certain geographical area. This paper aims to examine the impact of jobs-housing balance to traffic safety. In pursuing the above, this paper particularly focuses on modeling the traffic accidents by metropolitan area. The main results are as follows. First, three generalized linear models which are all statistically significant are developed. Jobs-housing balance factors are judged to significantly influence on traffic accidents in all models. Second, among common variables, the housing supply rate is analyzed to impact to decreasing, and economically active population and commuting trip attraction are analyzed to impact to increasing. Hence, the alleviation of jobs-housing mismatch is evaluated to be important. Finally, the jobs-housing and business trip rates in Seoul metropolitan area, and the cross-commuting rate in Busan-Ulsan metropolitan area are judged to be essential to transportation safety policies

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.44-51
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• 2009

The main purpose of this study is to identify urban spatial structure by applying geographic information system and remote sensing data. This study identifies the urban spatial structure of non-megalopolis by analyzing the spatial distribution of population and employment in the case of Daegu metropolitan area. For this purpose, multi-temporal satellite image data (Landsat TM; 1995, 2000 and 2005) were utilized through the geographic information system. The distance-decay estimations in terms of population and employment density show that Daegu region as a whole shows monocentric urban characteristics. However, some evidences of polycentricism such as low explanation power of monocentric urban model, rises in multiple employment centers, decentralization of employment are emerging.

• The Journal of Engineering Geology
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• v.2 no.2
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• pp.131-140
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• 1992

GIS(Geographic Information System) technology was applied for analysis of the potential degree of regional geologic hazard, especially landslide hazards in the suburb of Seoul City, whereby a regional geologic hazard map was produced. The factors causing a landslide such as slope geometry, geology, groundwater, soil property, rainfall and vegetation were incorporated through GIS in order to predict the potential hazards in this area. Cartographic simulation was finally made with these factors to produce a regional geologic hazard map. For this study, ARC/INFO and ERDAS systems were used in SUN 4-390 workstation.

• Journal of Korea Water Resources Association
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• v.36 no.1
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• pp.75-85
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• 2003

Urban rainfall-runoff procedures are more complex than the agricultural procedures due to the spreading and development of town. And the applications of theses models are more difficult due to the change of real basins. In this study, I applied SWMM and Expert System to get runoff characteristics of an urbanized basin. Noen in Daejeon is selected as a study basin. Real basin data of facilities, rainfall, runoff, and various rainfall intensity equations are used. An Expert System is used to get the parameters of this model. These results can be applied to analyze the reaction tendencies of the urban basin with the time distributions of design rainfall and the urbanization.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.42-42
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• 2016

지난 135년(1880~2014년) 동안 지구온난화에 따른 기후변화로 지구의 평균 기온은 $0.85^{\circ}C$ 상승하였으며, 이는 수문현상에 영향을 미쳐 강우량 및 강우강도가 증가하는 경향성을 보이고 있다. 이처럼 기후변화로 말미암아 수문 현상의 변화에 따른 불확실성이 커져 물 순환 과정의 정확한 파악이 더욱 어려워지고 있다. 따라서 미래 안정적인 물 공급을 위한 수자원계획 수립 및 관리를 위해 기후변화를 고려한 물 수요 예측이 필요하다고 하겠다. 본 연구에서는 도시화에 따라 물수요가 변화하고 있는 안성천을 대상유역으로 선정하여 기후변화를 고려한 미래 물 부족량을 산정하고자 하였다. 이를 위해, 기후변화 RCP 8.5 시나리오를 이용하여 미래 강수량을 모의하였고, 준 분포 강우-유출 모형인 SLURP 모형을 이용하여 미래 유출량을 분석하였다. 미래 유출량을 토대로 정확한 물 수요 예측을 위해 통합수자원평가계획 모형인 K-WEAP 모형을 이용하여 소유역별 물수지 분석을 위한 네트워크 및 시나리오를 구성하였다. 또한 용수이용량(생활, 공업, 농업용수)의 과거자료를 활용한 선형예측함수식을 통해 장래 물 수요 추정량을 산정하였다. 물 수지 분석 결과, 안성천 유역은 인구 증가, 급격한 도시화로 인해 용수 이용량이 증가하고 있었으나 농업용수는 점차적으로 감소하고 있었다. 따라서 생활 및 공업 용수에 대한 수요를 충족하지 못해 미래 물 부족량이 증가하고 있는 것으로 확인되었으며, 본 연구에서는 물부족 해소를 위한 방안으로 광역상수도 확충과 제한급수를 제시하여 분석을 수행하였다.

• Environmental and Resource Economics Review
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• v.23 no.1
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• pp.21-42
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• 2014

In this study, we are estimating the economic effects of the rising sea level due to the climate change in the Korean Eastern and Southern coastal areas. Using disaggregated regional data, we also estimate the optimal rate of coastal protection. We use FUND (The Climate Framework for Uncertainty, Negotiation and Distribution) in order to obtain estimates of the expected inundation ratios by geographical district. Our estimates suggest that in Busan the ratio of inundated land to total territory will likely constitute 3.19% by 2100, while the number in Gangwon-do province is estimated to be lower at only 0.1%. We estimate the associated economic damage to differ by geographical district with the economically active regions such as e.g. Busan and Ulsan cities, or the Gyeongsang-nam-do province, likely to sustain relatively more damage. In Busan and Ulsan where the coastal line is relatively short and the size of expected economic damage is rather high, we estimate the optimal rate of coastal protection to be at the level of 98% and 92%, respectively. In the Kyeongsang-nam-do area that is also likely to suffer a substantial economic damage due to the inundation, we suggest the optimal ratio of coastal protection to be set at the level of 78%~79%. In contrast, in the Kangwon-do province where the expected economic damage is estimated to be low, the optimal rate of coastal protection is estimated to be around 43%, depending on the scenario.

• Journal of the Korean Society for Library and Information Science
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• v.41 no.2
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• pp.237-256
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• 2007

This study examined DEA(Data Envelopment Analysis) and how it measures the efficiency of library units. DEA is a useful nonparametric method to evaluate the relative efficiency of a set of decision making units(DMUs) with multiple inputs and outputs. This study evaluated 102 different public libraries utilizing 4 inputs and 4 outputs focussing on the year 2005. For inefficient libraries, the study analysed the potential improvement and the source of inefficiency comparing the peer groups. The result of this study shows that efficiency of public libraries varies in different localities and forms of operation.