• 제목/요약/키워드: Urban Dynamics

검색결과 287건 처리시간 0.029초

Examining the dynamics among multiple actors through the mobilization of Public Procurement for Innovation in South Korea

  • Dongho Han;Tae Hyuk Kwon;Byoung Gun Kim
    • Asian Journal of Innovation and Policy
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    • 제12권3호
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    • pp.383-400
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    • 2023
  • This research focuses on examining the mobilization of Public Procurement for Innovation (PPI) in South Korea as a case study in technology innovation. By using the lens of policy mobility and qualitative research methodologies, it emphasizes the circulation of PPI is an outcome of an assemblage of multiple actors who are responsible for the introduction of PPI. The Public Procurement Service in South Korea has actively sought to understand and adopt the concept of PPI from developed countries. This initiative has been localized under the umbrella of 'innovative technology and product.' Throughout the mobilization, a cadre of technocrats, the Innovation Procurement Competence Center plays a pivotal role, and particularly encourages Small and Medium Enterprises to bolster their export capabilities, resulting in a reciprocal circulation of policies and programs from South Korea to foreign countries as well as within intra-urban area. Consequently, the above findings, revealing the nuanced evolution of policy mobility in local contexts, hold practical significance as they provide valuable insights and lessons for urban studies.

Hierarchical multiscale modeling for predicting the physicochemical characteristics of construction materials: A review

  • Jin-Ho Bae;Taegeon Kil;Giljae Cho;Jeong Gook Jang;Beomjoo Yang
    • Computers and Concrete
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    • 제33권3호
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    • pp.325-340
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    • 2024
  • The growing demands for sustainable and high-performance construction materials necessitate a deep understanding of their physicochemical properties by that of these heterogeneities. This paper presents a comprehensive review of the state-of-the-art hierarchical multiscale modeling approach aimed at predicting the intricate physicochemical characteristics of construction materials. Emphasizing the heterogeneity inherent in these materials, the review briefly introduces single-scale analyses, including the ab initio method, molecular dynamics, and micromechanics, through a scale-bridging technique. Herein, the limitations of these models are also overviewed by that of effectively scale-bridging methods of length or time scales. The hierarchical multiscale model demonstrates these physicochemical properties considering chemical reactions, material defects from nano to macro scale, microscopic properties, and their influence on macroscopic events. Thereby, hierarchical multiscale modeling can facilitate the efficient design and development of next-generation construction.

System Dynamics에 의한 도시활동의 동적 예측 (Dynamic Forecasting of Urban Activity by System Dynamic)

  • 황진성
    • 한국산업융합학회 논문집
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    • 제5권1호
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    • pp.53-64
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    • 2002
  • The purpose of this study was to predict the future urban activities effectively and rationally. For the purpose, a simulation model, based on SD, was built by integrating economic activities, land use and traffic of a city and by dividing Daegu Metropolitan City into seven districts and one county. To identify the effect of the development of a new city in the Dalsung County area, the future population and traffic volume of the city were predicted, using the model. The results are summarized as follows. The future population according to the development of a new city in the Dalsung County area was predicted, and the effects before and after the development twenty years later were compared. The future population of the Dalsung County was found to have slightly increased, whereas that of the adjoining Dalsuh Metropolitan District was found to has slightly decreased. For the other districts, there were no changes of the future population. It was found, therefore, that the development of a new city would have no effect on other districts. Then, the traffic volume according to the development of a new city in the Dalsung County area was also predicted. It was found that in the initial stage the traffic volume would increase with the increase in population of Dalsung County. It was predicted that particularly,. the traffic volume for the purpose of business would greatly increase. The traffic volume of Dalsuh Metropolitan District showed a slight decrease, whereas for the other districts, there were no changes of the traffic volume.

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CFD 모형을 이용한 도시 도로 협곡에서의 흐름 체계 분류 (Classification of Flow Regimes in Urban Street Canyons Using a CFD Model)

  • 김재진;백종진
    • 한국대기환경학회지
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    • 제21권5호
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    • pp.525-535
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    • 2005
  • Using a three-dimensional computational fluid dynamics (CFD) model with the $k-{\varepsilon}$ turbulence closure scheme based on the renormalization group theory, flow regimes in urban street canyons are classified according to the building and street aspect ratios. The transition between skimming flow (SF) and wake interference flow (WIF) is determined with the size of double-eddy circulation generated behind the upwind building. The transition between WIF and isolated roughness flow (IRF) is determined with the flow reattachment distance from the upwind building. The critical aspect ratios at which the flow transition occurs are found and compared with those in previous studies. The results show that the flow-regime classification method used in this study is quite reasonable and that the values of the critical aspect ratios are generally consistent with those in fluid experiments or large-eddy simulation. The regression equation describing a relation between the building and street aspect ratios at the flow-regime transition is presented.

초고층 공동주택의 주방.욕실 배기풍속 활용을 위한 기초연구 (A Basic Study on the Utilization of Kitchen and Bathroom Exhaust Wind Velocity in High-Rise Apartment)

  • 김성용;이용호;박진철;황정하
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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    • pp.226-231
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    • 2011
  • This study set out to review the air current fluidity in exhaust common ducts by installing an inlet pipe at a leisure space in the PS(Pipe Shaft)room for the sake of wind power generation with kitchen and bathroom exhaust common ducts of all the equipment and air conditioning shafts in high-rise apartment. The air current functionality of kitchen and bathroom exhaust common ducts was reviewed by analyzing wind velocity changes according to changes to the area of exhaust common ducts through a simulation, changes to the wind velocity of the kitchen hood by applying an external inlet pipe, changes to the usage factor of exhaust common ducts, and changes to wind velocity by altering the form of the ventilator at the bottom of the old exhaust common duct. It was a basic study on the utilization of exhaust wind velocity in exhaust common ducts.

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인공신경망 및 물질수지 모델을 활용한 하수처리 프로세스 시뮬레이터 구축 (Development of Wastewater Treatment Process Simulators Based on Artificial Neural Network and Mass Balance Models)

  • 김정률;이재현;오재일
    • 상하수도학회지
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    • 제29권3호
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    • pp.427-436
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    • 2015
  • Developing two process models to simulate wastewater treatment process is needed to draw a comparison between measured BOD data and estimated process model data: a mathematical model based on the process mass-balance and an ANN (artificial neural network) model. Those two types of simulator can fit well in terms of effluent BOD data, which models are formulated based on the distinctive five parameters: influent flow rate, effluent flow rate, influent BOD concentration, biomass concentration, and returned sludge percentage. The structuralized mass-balance model and ANN modeI with seasonal periods can estimate data set more precisely, and changing optimization algorithm for the penalty could be a useful option to tune up the process behavior estimations. An complex model such as ANN model coupled with mass-balance equation will be required to simulate process dynamics more accurately.

도심 고층건물 지붕에서의 소형 풍력발전기 발전량 예측 (Estimation of wind power generation of micro wind turbine on the roof of high rise buildings in urban area)

  • 최형식;장호남
    • 신재생에너지
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    • 제5권4호
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    • pp.21-27
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    • 2009
  • Potential yield of micro wind turbine on the roof of urban high rise buildings is estimated. Urban wind profile is modeled as logarithmic profile above the mean building height with roughness length 0.8, displacement 7.5 m. Mean wind velocity from the meteorological agency data at the hight of 50m is used. Wind velocity changes are simulated on the rectangular roof of 26, 45, 53 degree pitch and the circular roof by computational fluid dynamics and RNG k-$\varepsilon$ turbulence models. Wind velocity increased approximately by a factor of the order of 270 % on the 26 degree pitched roof. In the 100 m and 200 m high buildings, wind enhancement is greater at the front side than at the center of the building. In the building arrangement model wind velocity changes abruptly and it becomes wind gusts. When commercial wind turbines are installed on the building roof, average power and annual power generation enhanced by 3~4 times than normal wind velocity at 50m and 6 kw wind turbine can generate 1053 kwh per month on the 26 degree pitched roof at 50m height and sufficiently supply electrical power with 15 household for common electrical use and food waste disposer. However, power output will vary significantly by the wind conditions in the order of $\pm$ 20 %.

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Evaluation of urban pollutant washoff characteristics and treatment efficiency of a small constructed wetland

  • Reyes, Nash Jett DG.;Geronimo, Franz Kevin F.;Kim, Lee-Hyung
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2019년도 학술발표회
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    • pp.412-412
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    • 2019
  • Nature-based solutions (NBS) offer a wide variety of techniques that promote cost-efficient stormwater management practices. In particular, low impact development facilities utilize NBS principles to restore the ecosystem services in a highly-urbanized area. Despite the advancements in these technologies, several considerations should still be addressed to ensure optimum functionality and attainment of desired pollutant removal efficiency a LID facility. This study evaluated the mass flushing characteristics of pollutants in an urban catchment and the efficiency of a small constructed wetland (SCW) in treating urban stormwater runoff. 21 rainfall events from 2010 to 2018 were monitored to determine and quantify stormwater pollutants. The highest pollutant washoff was observed on rainfall depths ranging from 0.1mm to 10mm, whereas events with greater rainfall depths exhibited lower pollutant concentrations due to dilution effect. However, the SCW manifested lower pollutant-removal performance on rainfall depths exceeding 10mm due to the exceedance of the facility's design rainfall. This study is beneficial in assessing the dynamics of pollutant washoff and efficiency of LID facilities subjected under various external factors.

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Stress Dynamics in Seoul's Public Housing based on Housing Prices - Analyzing Discrimination and the Mitigating Role of Social Capital -

  • Jea-Heun KIM;Ja-Hoon KOO
    • 융합경영연구
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    • 제12권2호
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    • pp.61-71
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    • 2024
  • Purpose: This study explores the impact of discrimination experience on stress levels among Seoul's public housing complex residents, emphasizing the moderating role of social capital. Research design, data and methodology: Utilizing the 2019 Seoul public housing (PH) panel data and an ordered logit model, the research categorizes residents based on personal and environmental factors, contrasting them across different local housing price levels. Results: We find that public housing residents' experience of discrimination has a significant impact on stress, and local housing prices are positively related to stress. Interestingly, stress due to discrimination is more pronounced in high-priced neighborhoods, which are associated with real estate inequality. Conversely, this impact is less pronounced in lower-priced neighborhoods. Importantly, social capital not only has a significant moderating effect on stress for all residents, but in high-priced neighborhoods, it also moderates the stress caused by experiences of discrimination for social housing residents. Conclusions: These findings highlight the need for policy interventions to strengthen social capital and address socioeconomic disparities in public housing, and are significant for analyzing the nuanced relationship between neighborhood, housing affordability, discrimination, and stress in urban communities for public housing residents, which is a socially problematic issue.

Digital Twin based Household Water Consumption Forecasting using Agent Based Modeling

  • Sultan Alamri;Muhammad Saad Qaisar Alvi;Imran Usman;Adnan Idris
    • International Journal of Computer Science & Network Security
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    • 제24권4호
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    • pp.147-154
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    • 2024
  • The continuous increase in urban population due to migration of mases from rural areas to big cities has set urban water supply under serious stress. Urban water resources face scarcity of available water quantity, which ultimately effects the water supply. It is high time to address this challenging problem by taking appropriate measures for the improvement of water utility services linked with better understanding of demand side management (DSM), which leads to an effective state of water supply governance. We propose a dynamic framework for preventive DSM that results in optimization of water resource management. This paper uses Agent Based Modeling (ABM) with Digital Twin (DT) to model water consumption behavior of a population and consequently forecast water demand. DT creates a digital clone of the system using physical model, sensors, and data analytics to integrate multi-physical quantities. By doing so, the proposed model replicates the physical settings to perform the remote monitoring and controlling jobs on the digital format, whilst offering support in decision making to the relevant authorities.