• Construction Engineering and Management
• /
• v.20 no.1
• /
• pp.31-33
• /
• 2019

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.3
• /
• pp.47-57
• /
• 2023

In this study, pull-out tests were performed to investigate the effects of stirrup spacing, rebar diameter, and corrosion rate on bond strength of deformed bars in reinforced concrete. Twelve pull-out specimens with different stirrup spacing, rebar diameter, and corrosion rate were prepared following the RILEM RC6 guidelines. The test results showed that the bond strength of specimens with stirrups increased when the corrosion rate was less than 3%, whereas it decreased when the corrosion rate was more than 3%. On the other hand, the bond strength of specimens without stirrups decreased as the corrosion rate increased. The effect of rebar diameter was less significant compared to those of stirrup spacing and corrosion rate. A bond strength model for pull-out specimens was proposed considering stirrup ratio and corrosion rate, and the model showed the lowest error among the previous models.

• Atmosphere
• /
• v.31 no.2
• /
• pp.241-249
• /
• 2021

A smart city utilizes data collected from various sensors through the internet of things (IoT) and improves city operations across the urban area. Recently substantial research is underway to examine all aspects of data that requires for the smart city operation. Atmospheric data are an essential component for successful smart city implementation, including Urban Air Mobility (UAM), infrastructure planning, safety and convenience, and traffic management. Unfortunately, the current level of conventional atmospheric data does not meet the needs of the new city concept. New and innovative approaches to developing high spatiotemporal resolution of observational and modeling data, resolving the complex urban structure, are expected to support the future needs. The geographic information system (GIS) integrates the atmospheric data with the urban structure and offers information system enhancement. In this study we proposed the necessity and applicability of the high resolution urban meteorological dataset based on heavy fog cases in the smart city region (e.g., Sejong and Pusan) in Korea.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.5
• /
• pp.105-112
• /
• 2023

Steel fiber reinforced concrete (SFRC) exhibits enhanced strength and superior energy dissipation capacity compared to normal concrete, and it can also reduce crack propagation and fragmentation of concrete even when subjected to blast loads. In this study, the parameters defining failure surface and damage function of the K&C concrete nonlinear model were proposed to be applied for the properties of SFRC in LS-DYNA. Single element analysis has been conducted to validate the proposed parameters in the K&C model, which provided very close simulations on the compressive behavior of SFRC. In addition, blast analysis was performed on SFRC columns with different volume fractions of steel fibers, and the blast resistance of SFRC columns was quantitatively analyzed with Korea Occupational Safety & Health Agency (KOSHA) guidelines.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2021.05a
• /
• pp.285-288
• /
• 2021

4차 산업혁명의 출현과 함께 스마트공장, 스마트시티, 스마트러닝 등이 등장하면서 스마트 물관리시스템과 그 평가지표의 연구개발이 주요 사회문제로 대두되고 있다. 따라서 본 논문에서는 스마트 물 관리시스템의 자동화 수준 평가지표를 제안하고자 한다. 그 세부 연구내용은 다음과 같다. 첫째, 기존의 CMM과 SPICE 소프트웨어 프로세스 평가모델과 스마트공장의 평가지표를 검토하고, 스마트 정수처리장의 개념을 살펴본다. 둘째, 제안하는 스마트 물관리시스템의 평가지표에는 정수장의 주요 공정에 따라 착수 공정, 약품투입 공정, 혼화·응집 공정, 침전 공정, 여과 공정, 소독 공정의 6개 평가영역으로 세분화 하였고, 각 평가영역별로 0에서 4까지의 5단계 평가수준으로 구분하여 제안하였다.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.5
• /
• pp.130-138
• /
• 2023

In this study, experimental and analytical studies were conducted on the structural performance of permanent steel formed wide beams in construction stage. Four specimens were fabricated with different rib spacings of the side steel formwork and fixing plate depths, and experimental tests were performed to investigate the effects of variables on the structural performance. Also, an finite element analysis model of the steel permanent formwork wide beam was proposed based on the test results. Using the proposed model, parametric studies were performed with variables including rib spacing of the bottom and side steel formwork, spacing, depth, and thickness of the fixing plate to derive optimized details. Furthermore, an artificial neural network model was developed to easily estimate the deformation of the steel permanent formwork wide beam with various details.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.11
• /
• pp.226-232
• /
• 2020

The Stage-Gate is a market-oriented model that aims to launch new products on the market. Therefore, it can be appropriately introduced and applied to the operation and management of NSSCP, which is undergoing demonstration projects for Daegu and Siheung. In addition, smart cities have the characteristics of convergence and complex among various innovative technologies. When the Stage-Gate is introduced, the performance can be managed centering on the outcomes for each research institution. Therefore, the NSSCP is applying the Stage-Gate for the first time among national R&D projects to improve the quality of the research results and to demonstrate and commercialize them successfully. This paper reviews the operation results of the 1st and 2nd years when the State-Gate was introduced and analyzes the opinions of an R&D management agency, research institutes, and gate reviewers to present the supplementary and improvements for applying to the evaluation process for the next year. When operating the Stage-Gate by optimizing the situation for each project and being wary of inefficiencies caused by the rigid operation, it is expected that flexible evaluation for each outcome will be possible according to the convergence characteristics of smart cities.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.1
• /
• pp.415-423
• /
• 2021

Citizen participation and Living Lab are attracting interest as one of the major strategies for the success of smart cities. In a Living Lab, citizens, who are the end-users of technology, participate in the search for alternatives to define and solve problems and repeat experiments to verify alternatives in a circular process. The purpose of this research was to present an operating model of a citizen-participating online community platform to improve urban problems, implement and test it, and show its applicability. To this end, an operation model of a citizen-participating online community platform was proposed to improve urban problems. An online platform was designed and implemented to reflect the functions pursued by the operation model. Finally, a pilot test for the function was performed using the Oma Elementary School case located in Ilsan, Goyang-si, Gyeonggi-do. The operating model was designed with the city's pedestrian environment and children. As a result, the sharing and communicating process of urban issues among community members worked appropriately according to the designed intention. The Living Lab coordinator could visualize and view urban issues posted by users on a map based on location information. Visualizing the urban problem as a heat map confirmed that urban problems were concentrated in a specific area.

• Journal of Cadastre & Land InformatiX
• /
• v.50 no.1
• /
• pp.163-180
• /
• 2020

In this study, to build a spatial information infrastructure, which is a component of a smart city, a 3D digital twin model in the downtown area was built based on the latest spatial information acquisition technology, the drone. Several analysis models were implemented by utilizing. While the data processing time and quality of the three types of drone photogrammetry software are different, the accuracy of the construction model is ± 0.04 in the N direction and ± 0.03m in the E direction. In the m and Z directions, ± 0.02m was found to be less than 0.1m, which is defined as the allowable range of surveying performance and inspection performance for the boundary point in the area where the registration of the boundary point registration is executed. 1: 500 to 1 of the aerial survey work regulation: The standard deviation, which is the error limit of the photographic reference point of the 600 scale, appeared within 0.14 cm, and it was found that the error limit of the large scale specified in the cadastral and aerial survey was satisfied. In addition, in order to increase the usability of smart city realization using a drone-based 3D urban digital twin model, the model built in this study was used to implement Prospect right analysis, landscape analysis, Right of light analysis, patrol route analysis, and fire suppression simulation training. Compared to the existing aerial photographic survey method, it was judged that the accuracy of the naked eye reading point is more accurate (about 10cm) than the existing aerial photographic survey, and it is possible to reduce the construction cost compared to the existing aerial photographic survey at a construction area of about 30㎢ or less.

• Journal of the Korean Regional Science Association
• /
• v.33 no.1
• /
• pp.69-85
• /
• 2017

The positive changes in urban space and urban activities resulting from the urban services provided by Smart City is not accomplished by simply creating the physical environment built on ICT but through the cooperation and participation of citizens and private sector, which is in fact key to success. In this study, this research analyzed the role and structure of smart governance, which is a system of horizontal cooperation between public and private sector, and analyze its role in developing Smart City. The study also proposes various ways to facilitate such development in each of critical categories. For this purpose, this research studied 228 smart services across 11 categories registered in the Ministry of Land and Transport in Korea to analyze the spatial distribution of smart services by spatial hierarchy and their characteristics Also, the research conducted a case study of MetroGIS, which is an information collaboration governance system for the greater area of Minneapolis and St. Paul in the state of Minnesota, United States, to explore how governance is formed; its organizational structure; the role of sub-level organization hierarchy and their interrelationship. The results of the analysis suggest that the following conditions are required to create a smart city: first, public sector resource assistance for building community; second, enhanced communication system within the community and with outside the community; securing financial stability and establishing a model of sustainable development to induce the community to evolve into a governance form.