• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.432-443
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• 2018

This study aims to present the direction of development of a policy framework to solve the problems associated with Smart Cities. For this purpose, first, after investigating the development process of domestic smart cities, we examined various cases of smart city policies being established overseas. Second, we analyzed the existing research into smart cities, in order to understand the relationship between the major issues. Third, an expert interview was conducted based on the identified issues. Fourth, we presented the direction of development of a Smart City policy framework to solve the major problems associated with domestic and foreign smart cities. In the policy framework presented in this research, after subdividing the elements used for solving each problem, we linked them with the smart city components and selected matching executable agents to prepare solutions. Then, once the deliberation process of the National Smart City Committee and the Smart Urban Service Support Organization has been completed, the government will support it financially and politically. It also suggested that it is necessary to perform continuous information gathering and monitoring work, along with the construction of a control tower to strengthen the network effect between smart city related markets. This research has significance in that it presents the procedures required for efficiently responding to the problems arising in the smart city promotion process. It is expected that it will serve as the basis for establishing policies dealing with the development and advancement of domestic smart cities in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.370-378
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• 2020

The Construction Operations Building Information Exchange (COBie) collects and documents a large amount of information from different paths in one place during design and construction projects. This documented information is readily available as a means of continuously transferring data to the facility management systems used by building engineers. In this process, the COBie Worksheet, an open standard form, is used to input the information by simplifying the list required by the user. As a result, COBie was developed to improve dramatically how relevant information is obtained and updated to support operations, maintenance, and asset management at the design and construction stages. On the other hand, to use COBie, a great deal of manual work is required for information linkage and quality inspection with heterogeneous data models. These issues become obstacles to COBie-based facility management system development. This study analyzed the COBie information system and defined the framework for simpler operating maintenance information from BIM (Building Information Modeling). Moreover, the rules for facility management information submission, quality inspection, role definition of framework components, and information linkage were derived. COBie DB schema and support data linkages could be generated effectively based on the proposed framework in prototype development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.563-571
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• 2020

The purpose of a utility tunnel is to prevent repeated excavation as well as disasters and calamity. Domestic utility tunnels have been built in new town development plans. Currently, it is difficult to establish a utility tunnel due to a conflict of opinions by organization and financing. In this paper, research was conducted based on systematic procedures to suggest ways of improving the activation of utility tunnels in new cities and existing cities. First, a survey was conducted on the laws and status of utility tunnels, and problems were derived based on the review and analysis of the status. Finally, a method suggesting improvement measures to solve problems was applied. Based on the related laws and problems, the status of the development project was analyzed to select the installation scale in the utility tunnel, and the appropriate scale was reviewed through economic feasibility analysis of the installation scale under 2 million square meters. Considering the new city and the existing city, it was proposed to support administrative expenses to reduce the burden on additional installation areas and occupied institutions in a utility tunnel. In addition, improvement plans were presented for the details of the master plan for reviewing the installation regional of the utility tunnel. This paper will help officials to work smoothly when planning and installing utility tunnels in the future.

• Journal of the military operations research society of Korea
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• v.37 no.1
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• pp.49-70
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• 2011

This paper re-evaluated the research on the accounting information's effectiveness in military construction contracts, questioning the former research results on the central army's construction contract that was under the Qualification Assessment System, especially concerning the relations between the accounting information and the bidding ratios as well as the relations between the bidding rates and the defect rates, which targeted between 1 to 10 billions civil engineering, construction, electricity, telecommunication, and environment work types. Unlike the previous results, the relationship between the accounting information and the bidding rates was shown to be considerably limited that the bidding ratio could not be identified through the accounting information, while it could discern the relations with the defect rates. Furthermore, the proven results did not support the hypothesis that the differences in bidding rates could affect the defect ratio. However, through the prediction model of bidding and defect ratios, we could identity the accounting variables that influenced the ratios. Additionally through the results regarding the non-financial indexes in the Pre-Qualification items, the weight on these indexes could be adjusted. In conclusion, the research results has given us new understanding of the problems in the Qualification Assessment System which accounts for the majority of the current military construction contracts and provide validity on the government's expanded implementation of the Lowest Price Award System.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.35-46
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• 2007

In the study digital imagery was used to examine asphalt concrete pavements. With digitally mastered-image information that was filmed with a video camera fixed on a car travelling on road at a consistent speed, a road surface management system that can gain road surface information (Crack, Rutting, IRI) was developed using an object-oriented language "Delphi". This system was designed to improve visualized effects by animations and graphs. After analyzing the accuracy of 3-D coordinates of road surfaces that were decided using multiple image orientation and bundle adjustment method, the average of standard errors turned out to be 0.0427m in the X direction, 0.0527m in the Y direction and 0.1539m in the Z direction. As a result, it was found to be good enough to be put to practical use for maps drawn on scales below 1/1000, which are currently producted and used in our country, and GIS data. According to the analysis of the accuracy in crack width on 12 spots using a digital video camera, the standard error was found to be ${\pm}0.256mm$, which is considered as high precision. In order to get information on rutting, the physically measured cross sections of 4 spots were compared with cross sections generated from digital images. Even though a maximum error turned out to be 10.88mm, its practicality is found in work efficiency.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.427-432
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• 2020

In order to establish an effective forest management plan, it is necessary to investigate tree management information such as tree height and DBH(Diameter at breast height). However, research on convergence and application of data acquisition technology to improve the efficiency of existing forest survey methods is insufficient. Therefore, in this study, tree management information was constructed and analyzed using point cloud data acquired through a 3D scanner. Data on the study site was acquired using fixed and mobile 3D scanners, and the efficiency of the mobile 3D scanner was presented through comparison of working hours. In addition, tree management information for object management was constructed by classifying vegetation by object using point cloud data, and by constructing information on chest height diameter and height. As a result of the accuracy evaluation compared with the conventional measurement method, the difference in tree height was 0.02-0.09m and DBH was 0.01-0.04m. If information on the location of vegetation and crowns of each object is constructed through additional research in the future, the efficiency of the work related to forest management information construction can be greatly increased.

• Journal of the Korea Concrete Institute
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• v.28 no.2
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• pp.149-156
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• 2016

The service life in RC (Reinforced Concrete) is very important and it is usually obtained through deterministic method based on Fick's 2nd law and probabilistic method. This paper presents an evaluation of $P_{df}$(durability failure probability) and the related service life considering time-dependent behaviors in chloride diffusion and surface chloride content. For the work, field investigation is performed for RC structures exposed to chloride attack for 3.5~4.5years, focusing tidal zone (6.0 m) and sea shore (9.0 m), respectively. Random variables like cover depth, chloride diffusion coefficient, and surface chloride content are obtained, and $P_{df}$ and the service life are evaluated. Unlike the results from deterministic method using LIFE 365, probabilistic method with time effects on diffusion and surface chloride shows a relatively rapid change in the result, which is a significant reductions of service life in the case with low surface chloride content. For probabilistic evaluation of durability, high surface chloride content over $10.0kg/m^3$ is required and reasonable service life can be derived with consideration of time-dependent diffusion coefficient.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.44-52
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• 2002

Low temperature thermal desorption (LTTD) has become one of the cornerstone technologies used for the treatment of contaminated soils and sediments in the United States. LTTD technology was first used in the mid-1980s for soil treatment on sites managed under the Comprehensive Environmental Respones, Compensation and Liability Act (CERCLA) or Superfund. Implementation was facilitated by CERCLA regulations that require only that spplicable regulations shall be met thus avoiding the need for protracted and expensive permit applications for thermal treatment equipment. The initial equipment designs used typically came from technology transfer sources. Asphalt manufacturing plants were converted to direct-fired LTTD systems, and conventional calciners were adapted for use as indirect-fired LTTD systems. Other innovative designs included hot sand recycle technology (initially developed for synfuels production from tar sand and oil shale), recycle sweep gas, travelling belts and batch-charged vacuum chambers, among others. These systems were used to treat soil contaminated with total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAHs), pesticides, polychlorinated biphenyls (PCBs) and dioxin with varying degrees of success. Ultimately, performance and cost considerations established the suite of systems that are used for LTTD soil treatment applications today. This paper briefly reviews the develpoment of LTTD systems and summarizes the design, performance and cost characteristics of the equipment in use today. Designs reviewed include continuous feed direct-fired and indirect-fired equipment, batch feed systems and in-situ equipment. Performance is compared in terms of before-and-after contaminant levels in the soil and permissible emissions levels in the stack gas vented to the atmosphere. The review of air emissions standards includes a review of regulations in the U.S. and the European Union (EU). Key cost centers for the mobilization and operation of LTTD equipment are identified and compared for the different types of LTTD systems in use today. A work chart is provided for the selection of the optmum LTTD system for site-specific applications. LTTD technology continues to be a cornerstone technology for soil treatment in the U.S. and elsewhere. Examples of leading-edge LTTD technologies developed in the U.S. that are now being delivered locally in global projects are described.

• Journal of the Korea Concrete Institute
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• v.25 no.6
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• pp.621-630
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• 2013

Several techniques for steel corrosion detection are proposed and HCP (half cell potential) technique is widely adopted for field investigation. If concrete has cracks on surface, steel corrosion is rapidly accelerated due to additional intrusion of chloride and carbon dioxide ions. This study is for an evaluation of HCP in cracked concrete exposed chloride attack. For this work, RC (reinforced concrete) beams are prepared considering 3 w/c ratios (0.35, 0.55, and 0.70) and several cover depths (10~60 mm) and various crack widths of 0.0~1.0 mm are induced. For 35 days, SST (salt spraying test) is performed for corrosion acceleration, and HCP and corrosion length of rebar are evaluated. With increasing crack width, w/c ratios, and decreasing cover depth, HCP measurements increase. HCP evaluation technique is proposed considering the effects of w/c ratios, crack width, and cover depth. Furthermore anti-corrosive cover depths are obtained through Life365 program and the results are compared with those from this study. The results shows relatively big difference in cracked concrete, however provide similar anti-corrosive conditions in sound concrete.

• Journal of Navigation and Port Research
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• v.31 no.5 s.121
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• pp.421-426
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• 2007

Recently, the defect maintenance period of the new construction structure was extended from 5 years to 10 years. And according to change of realization on the quality of construction and maintenance, a development of semi-permanent method of construction is required for maintenance of blind parts of underwater structure, such as bridge, dam, harbor, etc. In this study, we proposed a floating type sector dry caisson, which is effective to the maintenance of submerged large structures. These large structures were being maintained incompletely, partly due to unskilled divers and difficult working condition. Considering the easiness of access to the maintenance area and the cost for set up the working structure, especially for the case of structure slabs close to the sea surface and harrow pile span structures, we developed and introduced a sector dry caisson instead of the full caisson structure. By doing this, it is easy to move out the caisson rapidly in emergence case. Therefore, we expect that the floating sector caisson will contribute to reduce working time and improve the quality of underwater work in future days.