• Title/Summary/Keyword: spatial panel model

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PIV Measurements of Ventilation Flow from the Air Vent of a Real Passenger Car (거대 화상용 PIV 시스템을 이용한 실차 내부 공기벨트 토출흐름의 속도장 측정 연구)

  • Lee, Jin-Pyung;Kim, Hak-Lim;Lee, Sang-Joon
    • Journal of the Korean Society of Visualization
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    • v.7 no.1
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    • pp.3-8
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    • 2009
  • Most vehicles have a heating, ventilating and air conditioning (HVAC) device to control the thermal condition and to make comfortable environment in the passenger compartment. The improvement of ventilation flow inside the passenger compartment is crucial for providing comfortable environment. For this, better understanding on the variation of flow characteristics of ventilation air inside the passenger compartment with respect to various ventilation modes is strongly required. Most previous studies on the ventilation flow in a car cabin were carried out using computational fluid dynamics (CFD) analysis or scale-down water-model experiments. In this study, whole ventilation flow discharged from the air vent of a real passenger car was measured using a special PIV (particle image velocimetry) system for large-size FOV (field of view). Under real recirculation ventilation condition, the spatial distributions of stream-wise turbulence intensity and mean velocity were measured in the vortical panel-duct center plane under the panel ventilation mode. These experimental data would be useful for understanding the detailed flow structure of real ventilation flow and validating numerical predictions.

Analysis of Factors Affecting Regional Total Fertility Rate: Using a Model Considering Cross-sectional Dependence (지역 합계출산율에 영향을 미치는 요인 분석: 횡단면 의존성을 고려한 모형을 이용하여)

  • So-Youn Kim;Su-Yeol Ryu
    • Asia-Pacific Journal of Business
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    • v.15 no.1
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    • pp.335-352
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    • 2024
  • Purpose - Low fertility rate is a serious problem, and this study analyzes factors affecting total fertility rate using panel data from 16 metropolitan cities and provinces in Korea from 2000 to 2022. Design/methodology/approach - Estimating the SAR model considering the weak cross-sectional dependence that exists in variables related to the regional total fertility rate, and using the DKSE estimation method considering the strong cross-sectional dependence. Findings - Estimation results considering weak and strong cross-sectional dependence were similar, confirming the robustness of the results. Female labor force participation rate has a positive effect on total fertility rate, and employment rate has no effect. However, the interaction term is a negative (-) sign. Crude marriage rate has a positive effect on total fertility rate, and apartment price has a slightly positive effect. Environmental factor has no effect, and policy factor has a negative effect. Research implications or Originality - In order for an increase in the female labor force participation rate to lead to an increase in the total fertility rate, qualitative improvements in female employment must be made. Financial investment policies for childbirth must increase their effectiveness. The problem of low fertility rate requires not only population policy but also social, economic, cultural, environmental, and policy conditions to be considered.

A Study on the Characteristic of Rococo Style in the Soubise Mansion (hotel de Soubise) (수비즈' 저택을 통해서 본 Rococo 양식의 특성에 관한 연구)

  • 한경희
    • Korean Institute of Interior Design Journal
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    • no.2
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    • pp.46-53
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    • 1994
  • The Soubise Mansin which construction ended in the latter half of 1730s has several rooms which symbolize Rococo which appeared in the 18 century. The work of the Soubis Mansion done by an architect, Boffrand , is a significant work in which he had introduced a new style of building , Rococo, based on a style of Regency, thereby showing a big leaf in that kind of art. In other words, with the elements already established in the days of Regency-white wood panel, gold molding, mirror technique, etc. -and the characteristics of unprecedent, outstanding spatial forms and Rococo decoration introduced. Rococo had enjoyed its peak of full flourish within the moderation of being never excessively magnificent, beautiful, and dignified. It is a remarkable thing that a model of such perfect ideal beauty was suggested even in the begining state of Rococo and it is deemed that such a point resulted in such influence on other places like the Versalilles Palace, etc.

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The Impact of Regional Economic Growth on Intraregional Disparities in Korea (지역경제 성장에 따른 지역 내부의 경제적 격차 추정에 관한 연구)

  • Lee, Ju-Han;Kim, Donghyun
    • Journal of the Korean Regional Science Association
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    • v.36 no.3
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    • pp.29-40
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    • 2020
  • The aims of this study to identify the relationship between regional economic growth and intraregional regional disparities. The 16 metropolitan area, the Capital region and the southeastern region of Korea were put in the spatial scope and the time range from 2005 to 2016. Regional gross domestic product data were used to show regional growth and intraregional disparity. Panel data for each spatial unit were established, panel unit root test and panel cointegration test were conducted to check the stability of the data. The DOLS method was used to identify relationship between regional economic growth and intraregional disparity, and the VECM model and Granger causality test was conducted to verify causality. The result of analysis of 16 metropolitan area units showed that the intraregional disparity increases as regional economic growth progresses. When the regional gross domestic product increased by 1%, the intraregional disparity increased by 1.258%, and there are short-term and long-term causality. Both the Capital region and the southeastern region had a mutual relationship between regional economic growth and intraregional disparity, but the disparity in the Capital region showed an increase and the southeastern region showed a decrease. The results of this study show that the regional disparity is increasing nationwide, but the Capital region and the southeastern region showed different stages of growth.

A Study of Rent Determinants of Small and Medium-Sized Office Buildings in Seoul Using a Dynamic Panel Model: Focusing on CBD and GBD Comparison (동적패널모형을 활용한 서울시 중소형 오피스 빌딩 임대료 결정 요인 연구: CBD(도심권)와 GBD(강남권) 비교를 중심으로)

  • NaRa Kim;JinSeok Yu;Jongjin Kim
    • Land and Housing Review
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    • v.14 no.4
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    • pp.47-62
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    • 2023
  • Using the dynamic panel model, this study investigates rent determinants for small and medium-sized office buildings in Korea's CBD and Gangnam areas, key business districts. The results reveal that rents for small and medium-sized office buildings in CBD and Gangnam areas are influenced by macroeconomic fluctuations and characteristics of buildings and locations, suggesting a market with both spatial consumer and investment goods attributes. There are several investment implications as follows. First, even if the location in the CBD area is advantageous, the practical limitations in renovating aging small and medium-sized office buildings must be taken into account when investing. Second, parking conditions are a key factor influencing rent prices in CBD areas, so evaluating the parking facilities and improvement potential of small and medium-sized office buildings is essential for investors. Finally, due to the high sensitivity of Gangnam's small and medium-sized office market to macroeconomic trends, it's vital to prioritize monetary policy shifts as a key factor in investment decisions.

Effects of High-Speed Train on Regional Population In-Migration - Focusing on Shrinking City and Demographic Structure - (고속철도가 지역 인구 이동에 미치는 영향 -지방소멸 위험과 인구 구조를 중심으로-)

  • Eunji Kim;Heeyeun Yoon
    • Journal of the Korean Regional Science Association
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    • v.40 no.2
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    • pp.91-106
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    • 2024
  • Around the world, many countries experiencing the issue of shrinking cities are continually expanding high-speed rail networks to enhance regional accessibility and address imbalances. This study analyzed the effects of high-speed train operations on the age-specific population migration in South Korean municipalities from 2012 to 2019, taking into account the risk levels of shrinking cities. For this purpose, an analysis was conducted using age-specific net in-migration population as the dependent variable, employing the spatial panel autoregressive model. The research results indicated that the influence of high-speed rail on regional population inflow varies depending on the risk level of shrinking city. In other words, high-speed railway operations had positive effects on population inflow in the capital areas and some major cities, while explained population outflow in the other regions. High-speed railways particularly exerted a significant impact on the inflow of the young and middle-aged population, representing the working age, but this effect was also limited to regions with a low risk of shrinkage. The findings of this study emphasize the importance of considering planned population and industrial attraction when installing high-speed rail with the goal of achieving regional balanced development and mitigating shrinkage. The results of this study also suggest the need for subsequent research to explore factors that positively influence population structure and inflow based on the level of shrinkage risk in each region, as well as the introduction of new policies tailored to the specific situations of each local government.

The Coordinated Development of New Urbanization Quality and Green Economy Efficiency in Jiangsu Province (중국 강소성 신도시화의 질적향상과 녹색경제효율성의 연계 발전에 관한 연구)

  • Manqian Cao;Jae-Yeon Sim
    • Industry Promotion Research
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    • v.8 no.2
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    • pp.165-176
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    • 2023
  • This article uses panel data of thirteen prefecture-level cities in Jiangsu Province from 2007 to 2021, and adopts entropy method, SBM model, and coupling coordination degree model to empirically study the development level of new model of urbanization and green economic efficiency in Jiangsu Province and the coupling coordination relationship between them. The results show that: the coupling coordination was in a moderate disorder and on the verge of disorder in 2008 and 2009. However, it steadily improved after 2010, and even witnessed a significant increase from 2018 to 2021. After that, it shows a high-quality coordination in 2021, indicating that the level of coordination between urbanization and green economic efficiency in Jiangsu province is steadily improving. Analyzed from a spatial perspective, the overall development of the regions in the province is sound and the coordination is growing at a significant rate, but there are still certain gaps in the coordinated development between the regions.

Assessment of the Potential Impact of Climate Change on the Drought in Agricultural Reservoirs under SSP Scenarios (SSP 시나리오를 고려한 농업용 저수지의 이수측면 잠재영향평가)

  • Kim, Siho;Jang, Min-Won;Hwang, Syewoon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.66 no.2
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    • pp.35-52
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    • 2024
  • This study conducted an assessment of potential impacts on the drought in agricultural reservoirs using the recently proposed SSP (Shared Socioeconomic Pathways) scenarios by IPCC (Intergovernmental Panel on Climate Change). This study assesses the potential impact of climate change on agricultural water resources and infrastructure vulnerability within Gyeongsangnam-do, focusing on 15 agricultural reservoirs. The assessment was based on the KRC (Korea Rural Community Corporation) 1st vulnerability assessment methodology using RCP scenarios for 2021. However, there are limitations due to the necessity for climate impact assessments based on the latest climate information and the uncertainties associated with using a single scenario from national standard scenarios. Therefore, we applied the 13 GCM (General Circulation Model) outputs based on the newly introduced SSP scenarios. Furthermore, due to difficulties in data acquisiton, we reassessed potential impacts by redistributing weights for proxy variables. As a main result, with lower future potential impacts observed in areas with higher precipitation along the southern coast. Overall, the potential impacts increased for all reservoirs as we moved into the future, maintaining their relative rankings, yet showing no significant variability in the far future. Although the overall pattern of potential impacts aligns with previous evaluations, reevaluation under similar conditions with different spatial resolutions emphasizes the critical role of meteorological data spatial resolution in assessments. The results of this study are expected to improve the credibility and accuracy formulation of vulnerability employing more scientific predictions.

Spatial Patterns of Urban Flood Vulnerability in Seoul (도시 홍수 취약성의 공간적 분포 - 서울 지역을 중심으로 -)

  • Kim, Jisoo;Sung, Hyo Hyun;Choi, Gwangyong
    • Journal of the Korean association of regional geographers
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    • v.19 no.4
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    • pp.615-626
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    • 2013
  • In this study, spatial patterns of the urban flood vulnerability index in Seoul are examined by considering climate exposure, sensitivity, and adaptability associated with floodings for recent 5 year (2006~2010) period by the smallest administrative unit called Dong. According to the results of correlation analyses based on the IPCC(Intergovernmental Panel on Climate Change)'s vulnerability model, among many variables associated with urban flooding, rainwater tank capacity, 1-day maximum precipitation and flood pumping station capacity have statistically-significant, and relatively-high correlations with the number of flood damage in Seoul. The flood vulnerability map demonstrates that the extensive areas along Anyang and Joongnang streams show relatively high flood vulnerability in Seoul due to high sensitivity. Especially in case of Joongnang stream areas, climatic factors also contribute to the increase of flood vulnerability. At local scales, several Dong areas in Gangdong-gu and Songpa-gu also show high flood vulnerability due to low adaptability, while those in Gangnam-gu do due to high sensibility and climate factor such as extreme rainfall events. These results derived from the flood vulnerability map by Dong unit can be utilized as primary data in establishing the adaptation, management and proactive policies for flooding prevention within the urban areas in more detail.

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Sea-Level Trend at the Korean Coast

  • Cho, Kwangwoo
    • Journal of Environmental Science International
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    • v.11 no.11
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    • pp.1141-1147
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    • 2002
  • Based on the tide gauge data from the Permanent Service for Meau Sea Level (PSMSL) collected at 23 locations in the Korean coast, the long-term sea-level trend was computed using a simple linear regression fit over the recorded length of the monthly mean sea-level data. The computed sea-level trend was also corrected for the vertical land movement due to post glacial rebound(PGR) using the ICE-4G(VM2) model output. It was found that the PGR-corrected sea-level trend near Korea was 2.310 $\pm$ 2.220 mm/yr, which is higher than the global average at 1.0∼2.0mm/yr, as assessed by the Intergovernmental Panel on Climate Change(IPCC). The regional distribution of the long-term sea-level trend near Korea revealed that the South Sea had the largest sea-level rise followed by the West Sea and East Sea, respectively, supporting the results of the previous study by Seo et al. However, due to the relatively short record period and large spatial variability, the sea-level trend from the tide gauge data for the Korean coast could be biased with a steric sea-level rise by the global warming during the 20th century.