• Korean Journal of Remote Sensing
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• v.33 no.5_3
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• pp.821-834
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• 2017

The increase in the rate of industrialization due to urbanization has caused the Urban Heat Island phenomenon where the temperature of the city is higher than the surrounding area, and its intensity is increasing with climate change. Among the cities where heat island phenomenon occurs, Seoul city has different degree of urbanization, green area ratio, energy consumption, and population density in each administrative district, and as a result, the strength of heat island is also different. So It is necessary to analyze the difference of Urban Heat Island Intensity by administrative district and the cause. In this study, the UHI intensity of the administrative gu and the administrative dong were extracted from the Seoul metropolitan area and the differences among the administrative districts were examined. and linear regression analysis were conducted with The variables included in the three categories(weather condition, anthropogenic heat generation, and land use characteristics) to investigate the cause of the difference in heat UHI intensity in each administrative district. As a result of analysis, UHI Intensity was found to be different according to the characteristics of administrative gu, administrative dong, and surrounding environment. The difference in administrative dong was larger than gu unit, and the UHI Intensity of gu and the UHI Intensity distribution of dongs belonging to the gu were also different. Linear regression analysis showed that there was a difference in heat island development intensity according to the average wind speed, development degree, Soil Adjusted Vegetation Index (SAVI), Normalized Difference Built-up Index (NDBI) value. Among them, the SAVI and NDBI showed a difference in value up to the dong unit and The creation of a wind route environment for the mitigation of the heat island phenomenon is necessary for the administrative dong unit level. Therefore, it is considered that projects for mitigating heat island phenomenon such as land cover improvement plan, wind route improvement plan, and green wall surface plan for development area need to consider administrative dongs belonging to the gu rather than just considering the difference of administrative gu units. The results of this study are expected to provide the directions for urban thermal environment design and policy development in the future by deriving the necessity of analysis unit and the factors to be considered for the administrative city unit to mitigate the urban heat island phenomenon.

• Journal of Korea Water Resources Association
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• v.44 no.10
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• pp.819-830
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• 2011

The multi-slope MUSCL, proposed by T. Buffard and S. Clain, determines slopes of conserved variables at each edge of a cell in the linear reconstructions of data. In this study, the second order accurate numerical model was developed according to the multi-slope MUSCL to solve the shallow water equations on the unstructured grids. The HLLL scheme of approximate Riemann solvers was used to calculate fluxes. For the review of the applicability of the developed model, the results of the model were compared to the 'isolated building test' and the 'model city flooding experiment' conducted as part of the IMPACT (Investigation of extreMe flood Processes And unCerTainty) project in Europe. There were limitations to predict abrupt rising of water depths by the resistance of model buildings and water depths at the specific locations among the buildings. But they were identified as the same problems also revealed in results of the other models to the same experiment. On the more refined meshes to the 'model city flooding experiment' simulated results showed good agreement with measurements. It was verified that the developed model simulated well the complex phenomena such as a dam-break problem and the urban inundation by flash floods.

• Journal of the Korean Institute of Gas
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• v.20 no.5
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• pp.64-71
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• 2016

According to the urban gas business law, electrical corrosion prevention measures shall be installed to the buried gas pipelines and the pipe-to-soil potentials should be measured at the test box at least once a year. Most of the test boxes installed in urban area are usually located on the road where the vehicle travels, therefore, it is difficult to measure the CP potentials at the test boxes. That is, we need traffic control when carrying out the measurement of the CP potentials on daytime when the traffic is heavy, or we have to measure the potentials in the late night when the traffic is light. To solve these difficulties, we have studied remotely CP potential measuring method by using the patrol car. We have installed solid reference electrodes and data loggers under the test boxes on the site and received the CP potentials from the data loggers when the vehicle moves. It was difficult to send and receive the data because the data logger was located under the ground. We have applied 3 different method including 2 antenna systems to achieve best effective way in receiving the data. We have found the remote CP measuring method by using a car can save more 20 times of measuring time than conventional measuring methods.

• Journal of the Korean Institute of Gas
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• v.22 no.4
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• pp.74-81
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• 2018

The Korean Government has proceeded petroleum gas pipeline construction business since 2014 for rural districts. The operating pressure of petroleum gas pipeline are from 25kPa to 75kPa which are different from that of natural gas pipeline. Petroleum gas pipeline pressure is ten or forty times higher than natural gas operating pressure. For this reason, petroleum gas pipeline has higher probability of accident occurrence from massive gas leakage. Korea Gas Safety Corporation begins to development excess flow valves and their performance testing equipment since 2017. The excess flow valves stop the gas flow when a overflow happened in gas pipeline. The excess flow valves are generally not installed in main pipeline, because that may block massive gas supply. So, the valves are installed in starting points of branch pipes. According to the number of house and amount of gas use, a shut-off point of exxcess flow valve is determined called as Trip Flow. The trip point is the most important thing of excess flow valve, so, it is required a equipment testing the performances of excess flow valve as trip point.

• The Journal of Society for e-Business Studies
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• v.15 no.3
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• pp.25-44
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• 2010

In recent years, Ubiquitous City (u-City), the integrated and convergence of ubiquitous services, infrastructure, technologies and city management of the new future development city, is being initiated by the Korean government and local authorities as their new national growth engine. However, a performance measurement system for evaluating and monitoring the impacts of U-City implementation is yet to be established. This paper aims to develop an integrated performance management system (PMS) and extensively used as a tool for managing performance activities to support the visions and goals of the u-City operations. Based on current reviews on the literature and interviews with experts drew Critical Success Factors (CSF) and Key Performance Indicators (KPI) by four different measurement domains including U-City services, infrastructure, technologies, management and developed into an integrated performance measurement system based on the Balanced Scored Card (BSC) perspective. The system also provides number of examples of 'u-City Strategy Map' which illustrates a causal relationship between CSFs to execute u-City visions and goals.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.399-406
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• 2004

최근 급속한 도시의 팽창과 산업의 발전으로 인하여 가스시설은 급속히 확대되고 있는 실정이다. 이러한 가스시설물의 중요성을 인식하고 많은 도시가스업체에서는 가스관망 시설정보를 전산화하여 항상 최신의 현황을 유지할 수 있는 가스시설물관리시스템을 개발하여 사용하고 있다. 그러나 이러한 시스템은 가스시설물의 현황파악 및 유지관리를 위한 기본적인 기능만을 제공하는 관계로, 가스 누출사고 발생시 정확한 사태의 파악과 함께 신속한 대책 마련을 위한 의사결정 지원이 어려운 실정이다. 따라서 체계적인 가스사고관리를 수행할 수 있는 응용시스템의 필요성이 증대되고 있다. 이러한 시점에서 본 연구에서는 가스사고분석을 신속하고 체계적으로 수행할 수 있는 가스사고관리 적용알고리즘 분석 및 최적의 알고리즘을 정립하여 가스사고관리시스템을 구현하였다. 본 연구를 통한 결과는 1ㆍ2차 차단밸브의 산정이 가능해짐으로써 빈번한 가스 누출사고 발생시 실시간으로 적정대처방안의 제시가 가능하게 되었다. 또한, 누출 최대가스량을 제시함으로써 누출에 대한 피해예상 분석을 위한 정보 제공 및 가스의 신속한 재공급을 위해 필요한 의사결정 지원 정보의 제공이 가능하게 되었다. 아울러, 가스누출사고에 의한 가스공급중단 관로 및 수용가에 대한 속성현황의 파악은 물론 시각적인 도식을 통한 전체적 현황파악이 가능하였다. 이러한 가스사고관리시스템의 개발을 통하여 사고 발생시 신속한 사고방안 제시 및 사고피해의 최소화를 위해 필요한 의사결정 지원 정보의 제공이 가능하게 됨으로써 국민의 안전 및 복지와 도시가스업체의 업무 효율화로 인한 예산절감 효과를 기대할 수 있다. 가시권 분석기능을 이용하여 실제 지형공간상에서 전파경로 손실치를 도시화함으로써 전파관리자가 무선서비스지역 설계, 전파음영지역 판단, 최적 중계기와 기지국 위치 선정에 기여할 것으로 판단된다.하지 않은 지역과 서로 다른 분광특성을 나타내므로 별도의 Segment를 형성하게 된다. 따라서 임상도의 경계선으로부터 획득된 Super-Object의 분광반사 값과 그 안에서 형성된 Sub-Object의 분광반사값의 차이를 이용하여 임상도의 갱신을 위한 변화지역을 탐지하였다.라서 획득한 시추코아에 대해서도 각 연구기관이 전 구간에 대해 동일하게 25%의 소유권을 가지고 있다. ？스굴 시추사업은 2008년까지 수행될 계획이며, 시추작업은 2005년까지 완료될 계획이다. 연구 진행과 관련하여, 공동연구의 명분을 높이고 분석의 효율성을 높이기 위해서 시료채취 및 기초자료 획득은 4개국의 연구원이 모여 공동으로 수행한 후의 결과물을 서로 공유하고, 자세한 전문분야 연구는 각 국의 대표기관이 독립적으로 수행하는 방식을 택하였다 ？스굴에 대한 제1차 시추작업은 2004년 3월 말에 실시하였다. 시추작업 결과, 약 80m의 시추 코아가 성공적으로 회수되어 현재 러시아 이르쿠츠크 지구화학연구소에 보관중이다. 이 시추코아는 2004년 8월 중순경에 4개국 연구팀원들에 의해 공동으로 기재된 후에 분할될 계획이다. 분할된 시료는 국내로 운반되어 다양한 전문분야별 연구에 이용될 것이다. 한편, 제2차 시추작업은 2004년 12월에서 2005년 2월 사이에 실시될 계획이다. 수백만년에 이르는 장기간에 걸쳐 지구환경변화 기록이 보존되어 있는 ？스굴호에 대한

• Journal of the Korean Institute of Gas
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• v.20 no.4
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• pp.33-43
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• 2016

Grinding, weld deposition, type A sleeve, type B sleeve, composite sleeve, hot tapping and clamp are used as the method to repair the buried pipelines in the United States, UK and Europe. In the event of defect to the pipeline, they have repaired the pipeline through the fitness-for-service assessments. In addition, they have guidelines for the possible repair methods to apply to each type of damage, which is occurred due to the 3rd party construction or corrosion. According to the KGS FS551, Safety Validation in Detail including ECDA(External Corrosion Direct Assessment) as one method of integrity management should be carried out for the old pipeline which supply natural gas as the middle pressure in Korea. Where a defect on the pipelines is found, on the result of Safety Validation in Detail, the pipelines should be repaired or replaced by new piping. However, there are no guidelines or regulations regarding the repair and reinforcement of pipeline, so that, cutting the damaged pipeline and replacing it as a segment of new pipe is the only way in Korea until now. We have suggested pipeline repair methods including type A, B sleeve, composite sleeve, after the survey of foreign repair method and standards including the method of United States and the United Kingdom, and after analysis of the results on pipeline repair test including type A, type B sleeve and composite sleeve.

• Land and Housing Review
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• v.13 no.1
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• pp.99-112
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• 2022

There is growing significance in securing urban parks and enhancing their accessibility due to irrational residential developments and apartment construction. Accordingly, Daejeon Metropolitan City has carried out urban park management projects to improve the quality of parks and create new parks. Daejeon Metropolitan City generates and manages park data for the purpose of management by the administrative district. However, these datasets take different forms in each administrative district. This study integrates the park data in Daejeon, generated by administrative districts, into the same format and generates geographic information data with the area information of each park for analysis. Analysis results show that urban parks are severely imbalanced across administrative districts, requiring new policy measures. In addition, by normalizing the park analysis results and, then, creating their rankings, this study compares them with the actual park information in detail to confirm the soundness of the dataset. The analysis results provide implications to improve the management of urban parks. This study proposes integrated datasets and the continued management of them in each administrative district by including essential data that can feature the objective information of the parks along with park evaluation indicators based on previous studies.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.4
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• pp.74-82
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• 2011

During the industrialization and urbanization of the country, urban rivers have been covered over and developed without forethought and thus became estranged from spaces utilized by area residents in everyday life. Recently, an influx of people and uses have increased largely because accessibility improved through restoration projects which have transformed these river areas into pleasant environments. It thus appears that these projects have an impact on community consciousness for area residents who live near the restored rivers to some extent. The purpose of this study was to determine via questionnaire the effects and influences of urban river restoration on area residents targeting visitors to Seongnaecheon(stream), Songpa-gu, Seoul, which has been restored recently. Factors in the questionnaire analysis included such items as the use status of Seongnaecheon, community consciousness(feeling of belonging, solidarity, feeling settled), and a before and after comparison of the restoration(change of consciousness, regional effects), etc. According to the results of analysis, visitors who have utilized the stream more than 1~2 times per week after the restoration project accounted for the greatest portion. The main purposes of these visits were to 'rest' and 'exercise' while the ratio of using it as a 'meeting space with neighbors and strangers' was low. Community consciousness of area residents using Seongnaecheon was generally high. As a result of an analysis of consciousness differences between groups after dividing visitors into 3 groups according to the frequency of visits, there were significant differences in the consciousness level between groups with high community consciousness levels in visitors who visited frequently. In consideration of these results, the provision of programs along with proper facilities that can be used is deemed important for area residents so as to inspire community consciousness of the area by means of activating both community activities and the progressive use of the restored river.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.1029-1042
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• 2021

As part of the next-generation Compact Advanced Satellite 500 (CAS500) project, CAS500-4 is scheduled to be launched in 2025 focusing on the remote sensing of agriculture and forestry. To obtain quantitative information on vegetation from satellite images, it is necessary to acquire surface reflectance through atmospheric correction. Thus, it is essential to develop an atmospheric correction method suitable for CAS500-4. Since the absorption and scattering characteristics in the atmosphere vary depending on the wavelength, it is needed to analyze the sensitivity of atmospheric correction parameters such as aerosol optical depth (AOD) and water vapor (WV) considering the wavelengths of CAS500-4. In addition, as CAS500-4 has only five channels (blue, green, red, red edge, and near-infrared), making it difficult to directly calculate key parameters for atmospheric correction, external parameter data should be used. Therefore, thisstudy performed a sensitivity analysis of the key parameters (AOD, WV, and O₃) using the simulated images based on Sentinel-2 satellite data, which has similar wavelength specifications to CAS500-4, and examined the possibility of using the products of GEO-KOMPSAT-2A (GK2A) as atmospheric parameters. The sensitivity analysisshowed that AOD wasthe most important parameter with greater sensitivity in visible channels than in the near-infrared region. In particular, since AOD change of 20% causes about a 100% error rate in the blue channel surface reflectance in forests, a highly reliable AOD is needed to obtain accurate surface reflectance. The atmospherically corrected surface reflectance based on the GK2A AOD and WV was compared with the Sentinel-2 L2A reflectance data through the separability index of the known land cover pixels. The result showed that two corrected surface reflectance had similar Seperability index (SI) values, the atmospheric corrected surface reflectance based on the GK2A AOD showed higher SI than the Sentinel-2 L2A reflectance data in short-wavelength channels. Thus, it is judged that the parameters provided by GK2A can be fully utilized for atmospheric correction of the CAS500-4. The research findings will provide a basis for atmospheric correction of the CAS500-4 in the future.