• Title/Summary/Keyword: urban studies

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Analysis of Relationships between Features Extracted from SAR Data and Land-cover Classes (SAR 자료에서 추출한 특징들과 토지 피복 항목 사이의 연관성 분석)

  • Park, No-Wook;Chi, Kwang-Hoon;Lee, Hoon-Yol
    • Korean Journal of Remote Sensing
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    • v.23 no.4
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    • pp.257-272
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    • 2007
  • This paper analyzed relationships between various features from SAR data with multiple acquisition dates and mode (frequency, polarization and incidence angles), and land-cover classes. Two typical types of features were extracted by considering acquisition conditions of currently available SAR data. First, coherence, temporal variability and principal component transform-based features were extracted from multi-temporal and single mode SAR data. C-band ERS-1/2, ENVISAT ASAR and Radarsat-1, and L-band JERS-1 SAR data were used for those features and different characteristics of different SAR sensor data were discussed in terms of land-cover discrimination capability. Overall, tandem coherence showed the best discrimination capability among various features. Long-term coherence from C-band SAR data provided a useful information on the discrimination of urban areas from other classes. Paddy fields showed the highest temporal variability values in all SAR sensor data. Features from principal component transform contained particular information relevant to specific land-cover class. As features for multiple mode SAR data acquired at similar dates, polarization ratio and multi-channel variability were also considered. VH/VV polarization ratio was a useful feature for the discrimination of forest and dry fields in which the distributions of coherence and temporal variability were significantly overlapped. It would be expected that the case study results could be useful information on improvement of classification accuracy in land-cover classification with SAR data, provided that the main findings of this paper would be confirmed by extensive case studies based on multi-temporal SAR data with various modes and ground-based SAR experiments.

Land Cover Classification of the Korean Peninsula Using Linear Spectral Mixture Analysis of MODIS Multi-temporal Data (MODIS 다중시기 영상의 선형분광혼합화소분석을 이용한 한반도 토지피복분류도 구축)

  • Jeong, Seung-Gyu;Park, Chong-Hwa;Kim, Sang-Wook
    • Korean Journal of Remote Sensing
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    • v.22 no.6
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    • pp.553-563
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    • 2006
  • This study aims to produce land-cover maps of Korean peninsula using multi-temporal MODIS (Moderate Resolution Imaging Spectroradiometer) imagery. To solve the low spatial resolution of MODIS data and enhance classification accuracy, Linear Spectral Mixture Analysis (LSMA) was employed. LSMA allowed to determine the fraction of each surface type in a pixel and develop vegetation, soil and water fraction images. To eliminate clouds, MVC (Maximum Value Composite) was utilized for vegetation fraction and MinVC (Minimum Value Composite) for soil fraction image respectively. With these images, using ISODATA unsupervised classifier, southern part of Korean peninsula was classified to low and mid level land-cover classes. The results showed that vegetation and soil fraction images reflected phenological characteristics of Korean peninsula. Paddy fields and forest could be easily detected in spring and summer data of the entire peninsula and arable land in North Korea. Secondly, in low level land-cover classification, overall accuracy was 79.94% and Kappa value was 0.70. Classification accuracy of forest (88.12%) and paddy field (85.45%) was higher than that of barren land (60.71%) and grassland (57.14%). In midlevel classification, forest class was sub-divided into deciduous and conifers and field class was sub-divided into paddy and field classes. In mid level, overall accuracy was 82.02% and Kappa value was 0.6986. Classification accuracy of deciduous (86.96%) and paddy (85.38%) were higher than that of conifers (62.50%) and field (77.08%).

Regulatory Reform for Service Development (서비스발전을 위한 규제개혁의 새 패러다임)

  • Jeong, Ki-Oh
    • Journal of Service Research and Studies
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    • v.6 no.3
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    • pp.1-15
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    • 2016
  • Despite that Korea has tried radical efforts in the global flow of regulatory reform in the past twenty years, the result was not radical at all, but rather disappointing. One examines the possibility of paradigm shift in regulatory reform based on new theoretic perspectives. Regulatory reform, one argues, is not just a neo-liberal approach to cut off overflowing regulation. It is a highly conflictual struggle in state order to move from industrial age paradigm to service age paradigm. In the process of the great shift states become integrated into the world of life constructed by the exercise of civil rights. The relation between the civic socio-economic life and the state apparatus became totally different. Past effort for deregulation missed this point without correct recognition of the role of civil freedom and rights in service economy. One treats three typical forms of regulation whereby conventional rules and regulations effectively damper the development of services: reciprocal perspective in contract management, industrial mind in urban and spaces design, and old way of human capital management. According these analyses a new initiative of regulatory reform is proposed to take place at the National Assembly.

Trend Analysis for the Beehive Removal Dispatch of the 119 Rescue Teams in Busan (부산지역 119구조대의 벌집 제거 출동 경향 분석)

  • Lee, Geun-chul;Kim, Byoung-Gwon;Seo, Il-hwan
    • Journal of the Society of Disaster Information
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    • v.17 no.4
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    • pp.667-673
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    • 2021
  • Purpose: The aim of this study is to analyze the trend for the dispatch of the 119 rescue teams to remove the beehive according to the distribution of temperature and time in Busan metropolitan city for 5 years from 2015. Method: From January 2015 to December 2019, 11 fire stations in Busan were dispatched and the source data of rescue and emergency activities were collected. The number of beehive removal dispatches was determined by the Busan Metropolitan Fire Station's jurisdiction over the past five years, and the temperature meteorological factors and honeycomb removal dispatches were analyzed in frequency and percentage. Result: The frequency of dispatch began to increase at an monthly average temperature of more than 20℃ and was higher at 23℃ to 29℃ than other temperature range. The highest frequency of dispatch was 7,900 cases in 2017. In particular, we found that the start timing of the honeycomb removal is getting faster as the year goes by. Gijang-gun had the largest frequency of dispatch, and Haeundae-gu, Geumjeong-gu, and Nam-gu were found to have a higher that. Conclusion: We found that the start timing of the honeycomb removal is getting faster as the year goes by and temperature changes. The results of this study are considered to be useful in future studies of wasps in urban areas.

A Study on the Application of CIGS Solar Cells to Improve the Aesthetics of Public Facilities (공공시설물 심미성 향상을 위한 CIGS 태양전지 적용 방안 연구)

  • Lee, Saem;Seo, Ji-Young;Park, Su-Jy;Nam, Won-Suk;Jang, Jung-Sik
    • Journal of the Korea Convergence Society
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    • v.12 no.12
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    • pp.235-243
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    • 2021
  • As environmental problems accompanied by industrialization have emerged worldwide, solar and wind energy have entered the stage of commercialization, especially in Korea. In addition, research on improving aesthetics using solar cells is being actively conducted. Examples include developing a transmissive solar cell and developing a solar cell with flexibility and color. Therefore, in line with the upward trend of solar cell development and solar cell-based public facility installation, we will present guidelines for designing public facilities using solar cells to improve aesthetics. First of all, components were derived to increase the suitability of solar cell application through literature surveys on solar cells and case studies on public facilities using solar cells. Next, through prior research on public facility guidelines, we established evaluation principles and drafted design guidelines. Based on this, a Delphi survey was conducted on a group of experts to verify its validity. Design guidelines for solar cells application measures to improve the final public design aesthetics were derived. The goal is to improve the public facilities using solar cells, through Accessibility and cognition, Usability, Shape and aesthetics, Sustainability and energy efficiency, Continuity with the urban landscape. And it is expected that this data will be used to improve the aesthetics of public design using solar cells in the future.

Comparative Analysis of BIM Acceptance Factors between Korea and China (한국과 중국의 BIM 수용영향요인 비교분석)

  • Song, Jingxu;Lee, Seulki;Yu, Joungho
    • Korean Journal of Construction Engineering and Management
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    • v.22 no.6
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    • pp.3-14
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    • 2021
  • In the Chinese construction industry, the utilization of Building Information Modeling (BIM) aims to increase the total output of the construction industry by solving the problem of inefficient interoperability in the construction industry. In 2011, the Chinese Ministry of Housing and Urban-Rural Development despite the technical advantages of BIM and the government policy, the BIM adoption rate in China is lower than 45%. Meanwhile, as the South Korean construction industry is a step ahead of its Chinese counterpart in introducing and utilizing BIM, it is expected that BIM is more actively utilized and accepted in South Korea than in China. According to a comparative study based on the hype-cycle theory, South Korea is at a more advanced stage of introducing BIM, than in China. This study aimed to suggest how to increase BIM utilization rates in China. To this end, this study comparatively analyzed factors affecting BIM acceptance between China and South Korea. For the comparative analysis of the BIM acceptance factors between China and South Korea, literature reviews on the technology acceptance model (TAM) and BIM acceptance model were carried out, and based on that, the BIM acceptance factors were classified. Other BIM acceptance factors were also added and considered, as they reflected Chinese national characteristics and construction industry. As for the derived BIM acceptance factors, construction project participants, especially actual BIM users in China and South Korea, were targeted for the survey. A t-test using SPSS 22.00 was carried out to identify significant differences in data. Finally, based on the t-test results, this study suggested ways of improving the BIM utilization rate in China. Based on the findings, this study is expected to contribute to activating BIM adoption in the Chinese construction industry and also to set a theoretical foundation for future studies on BIM utilization in the industry.

Research on rapid source term estimation in nuclear accident emergency decision for pressurized water reactor based on Bayesian network

  • Wu, Guohua;Tong, Jiejuan;Zhang, Liguo;Yuan, Diping;Xiao, Yiqing
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2534-2546
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    • 2021
  • Nuclear emergency preparedness and response is an essential part to ensure the safety of nuclear power plant (NPP). Key support technologies of nuclear emergency decision-making usually consist of accident diagnosis, source term estimation, accident consequence assessment, and protective action recommendation. Source term estimation is almost the most difficult part among them. For example, bad communication, incomplete information, as well as complicated accident scenario make it hard to determine the reactor status and estimate the source term timely in the Fukushima accident. Subsequently, it leads to the hard decision on how to take appropriate emergency response actions. Hence, this paper aims to develop a method for rapid source term estimation to support nuclear emergency decision making in pressurized water reactor NPP. The method aims to make our knowledge on NPP provide better support nuclear emergency. Firstly, this paper studies how to build a Bayesian network model for the NPP based on professional knowledge and engineering knowledge. This paper presents a method transforming the PRA model (event trees and fault trees) into a corresponding Bayesian network model. To solve the problem that some physical phenomena which are modeled as pivotal events in level 2 PRA, cannot find sensors associated directly with their occurrence, a weighted assignment approach based on expert assessment is proposed in this paper. Secondly, the monitoring data of NPP are provided to the Bayesian network model, the real-time status of pivotal events and initiating events can be determined based on the junction tree algorithm. Thirdly, since PRA knowledge can link the accident sequences to the possible release categories, the proposed method is capable to find the most likely release category for the candidate accidents scenarios, namely the source term. The probabilities of possible accident sequences and the source term are calculated. Finally, the prototype software is checked against several sets of accident scenario data which are generated by the simulator of AP1000-NPP, including large loss of coolant accident, loss of main feedwater, main steam line break, and steam generator tube rupture. The results show that the proposed method for rapid source term estimation under nuclear emergency decision making is promising.

The Research Trends in Journal of the Korean Institute of Landscape Architecture using Topic Modeling and Network Analysis (토픽모델링과 연결망 분석을 활용한 국내 조경 분야 연구 동향 분석 - 한국조경학회지를 대상으로 -)

  • Park, Jae-Min;Kim, Yong Hwan;Sung, Jong-Sang;Lee, Sang-Seok
    • Journal of the Korean Institute of Landscape Architecture
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    • v.49 no.2
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    • pp.17-26
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    • 2021
  • For the past half century, the Journal of the Korean Landscape Architecture has been leading the landscape architecture research and industry inclusively. In this study, abstracts of 1,802 articles were collected and analyzed with topic modeling and network analysis method. As a result of this paper, a total of 27 types of subjects were identified. Health and healing in the field of environmental psychology, garden and aesthetics, participation and community, modernity, place and placenness, microclimate, tourism and social equity also have been continued as important research area in this journal. Modernity, community and urban regeneration is hot topics and ecological landscape related topics were cold topics. Although there was a difference by subject, the variability of the research subjects appeared after the 2000s. In Network analysis, it shows that 'Park' is a representative keyword that can symbolize the journal, and 'landscape' is also important a leading area of the journal. Looking at the overall structure of the network, it can be seen that the journal conducts research on 'utilizing', 'using', and creating 'park', 'landscape', and 'space'. This study is meaningful in that it grasped the overall research trend of the journal by using topic modeling and network analysis of text mining.

The Effect of Macroeconomic and Real Estate Policies on Seoul's Apartment Prices (거시경제와 부동산정책이 서울 아파트가격에 미치는 영향 연구)

  • Bae, Jong-Chan;Chung, Jae-Ho
    • Land and Housing Review
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    • v.12 no.4
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    • pp.41-59
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    • 2021
  • This study reviews theoretical considerations and past studies about real estate prices, macroeconomic variables, and real estate policies. Monthly data from January 2003 to June 2021 are used, and a VEC model, the most widely used multivariate time series analysis method, is employed for analysis. Through the model, the effects of macroeconomic variables and real estate regulatory policies on real estate prices in Seoul are analyzed. Findings are summarized as follows. First, macroeconomic variables such as money supply and interest rates do not have a significant impact on Seoul's apartment prices. Due to the high demand for housing and insufficient supply, there is a demand for buying a home regardless of macroeconomic booms or recessions. Second, tax and financial regulatory policies have an initial impact on the rise in apartment prices in Seoul, and their influence diminishes over time. Third, anti-speculation zones are expected to decrease apartment prices through the suppression of demand. However, these zones cause a rise in apartment prices. This could be understood as a lock-in effect due to the strengthening of capital gains tax. Fourth, the price ceiling did not decrease apartment prices. These findings propose that, in Seoul, where demand is high and supply is insufficient, the supply of high-quality and sufficient housing should be prioritized over various regulations such as tax regulations, financial regulations, anti-speculation zones, and price caps. Moreover, the findings provide an implication that city-specific real estate policies should be implemented for Seoul rather than regulation-oriented approaches in public policy.

EU Smart City Demonstration and Expansion by the Lighthouse Project (EU 라이트하우스 프로젝트 분석을 통한 스마트시티 실증과 확산을 위한 시사점 도출)

  • Jung, Seung-Hyun;Kim, Min-Ju
    • Land and Housing Review
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    • v.12 no.2
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    • pp.1-12
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    • 2021
  • The purpose of this study is to provide implications for the demonstration and the spread of smart cities. For this, the European Lighthouse project, a well-known smart city initiative, is analyzed. This article investigates agendas, applied solutions, stakeholders and cooperation, and expansion strategies in the 18 Lighthouse projects implemented by the EIP-SCC Smart City Demonstration Project. Four implications are discussed for Korean smart city projects. First, in promoting smart cities, clear philosophies and principles should be established in response to global issues such as climate change. Second, smart cities should be understood as the approaches for problem-solving rather than simply applying advanced technology. Third, a business system should be established in a way to meet the needs of the actors participating in the smart city demonstration project. Finally, an evaluation framework should be established to verify the performance of the project. High-performing best-practice projects should be supported by articulating their standards for their lessons to be spread into other cities. The implications presented here can contribute to developing smart city models along with follow-up studies.