• International conference on construction engineering and project management
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• 2009.05a
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• pp.354-360
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• 2009

The demands for large-scale construction projects such as Mega-projects are largely increasing due to the rapid growth of increasing populations as well as the need to replace existing buildings and infrastructure. Increasing costs of materials, supplies, and labors require the first cost estimates at the preliminary planning stage to be as accurate as possible. This paper presents the results obtained from the survey on evaluating nine critical success factors that influence the accurate first cost estimates for large-scale projects from practical experiences. It then examines the current cost structures of construction companies for large-scale projects, followed by the causes for cost and schedule overrun. Twenty completed surveys were collected and the Analytic Hierarchy Process was applied to analyze the data. The results indicate that technology issues, the contract type, and social and environmental impacts are the significant leading factors for accurate first cost estimates of large-scale construction projects.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.57-58
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• 2020

Recently, government office buildings have become important in reducing maintenance costs. However, the loss of information raised a problem for maintenance work that could not meet the needs of users. Therefore, this study proposed a BIM-based integrated maintenance system for public offices in Jeju to efficiently maintenance work. The system can be integrated with IoT sensors, big data and artificial intelligence technologies to integrate information that occurs throughout the building's entire life cycle to exchange information. This system is also scalable to buildings, plants, region and urban infrastructure facilities as well as single buildings. It is expected that the system will provide reliable, high-quality, real-time information for efficient maintenance work, thereby supporting decision making and appropriate budget planning.

• Earthquakes and Structures
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• v.25 no.5
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• pp.369-383
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• 2023

Seismic resilience (SR) plays a vital role in evaluating and improving performance losses along with saving repair costs of structures from potential earthquakes. To further explore the developments, hotspots, and trend directions of SR, a total of 901 articles are obtained from the Web of Science (WoS) database. CiteSpace software is used to conduct a bibliometric analysis, which indicates an upward trend of publications in SR and explores the relationship of countries, journals, cited references, and keywords based on visual maps and detailed tables. Then, based on the results of the bibliometric analysis, a state-of-the-art review is conducted to further explore the current challenges and trend directions of SR. The trend directions can be divided into five categories: (a) SR assessments of infrastructure structures, (b) multi-hazard quantifications of SR, (c) seismic resilient structures, (d) refining and calibrating analytical models, and (e) multi-criteria decision-making frameworks for sustainability and SR.

• Journal of information and communication convergence engineering
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• v.22 no.3
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• pp.215-220
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• 2024

This paper presents an efficient method for expanding interconnections in scenarios involving the reconstruction of interconnections across arbitrarily divided planes. Conventionally, such situations necessitate rebuilding interconnections based on all targets, ensuring minimal cost but incurring substantial time expenditure. In this paper, we present a tinkered tree algorithm designed to efficiently expand interconnections within a Euclidean plane divided into m randomly generated regions. The primary objective of this algorithm is to construct an optimal tree by utilizing the minimum spanning tree (MST) of each region, resulting in swift interconnection expansion. Interconnection construction is applied in various design fields. Notably, in the context of ad hoc networks, which lack a fixed-wired infrastructure and communicate solely with mobile hosts, the heuristic proposed in this paper is anticipated to significantly reduce costs while establishing rapid interconnections in scenarios involving expanded connection targets.

• Journal of Korea Port Economic Association
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• v.33 no.3
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• pp.17-34
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• 2017

This study aims to analyze the freight transport demand and benefit for the introduction of an automated freight transport system focusing on the Global Industry and Logistics City (GILC) in Busan. In pursuit of this aim, four alternatives were calculated - using the freight volume estimating methods and included, the number of businesses, the number of employees set up, future estimated cargo volume, and switched volume from other transport modes into the GILC. Economic benefits were analyzed against social benefits and costs accordingly. The result of the freight transport demand forecast found, the cargo volume of "Alternative 2-1" to be the most advantageous, applying the number of employee unit method and proportion of employees in Gangseo-gu, Busan. In addition to the conventional analysis of direct benefit items (reduction of transport time, traffic accidents and environmental costs), this study also considered additional benefit items (congestion costs savings, and road maintenance costs in terms of opportunity cost). It also considered advanced value for money research in guidance on rail appraisal of U.K, Federal Transport Infrastructure Plan 2003 of Germany, and RailDec of the United States. The study aims to further contribute to estimating minimum cargo transport demands and assess the economic feasibility of the introduction of new intermodal automated freight transport systems in the future.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.89-97
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• 2015

This paper analyzes the duration of the construction document (CD) phase of 42 large public building projects delivered by the total solution service of Public Procurement Services in Korea from 2009 to 2014. The quality of construction documents significantly affects the quality of construction and facility management. Thus, securing appropriate time for the CD phase during project planning is important for the quality of a project. Currently, the duration of the CD phase is planned based on the construction costs of a project following a notice of the Ministry of Land, Infrastructure and Transport. However, our analysis results showed that the correlation between the actual duration of the CD phase and construction costs is very weak. The actual CD phase takes 1.33-1.79 times longer than the planned duration. The practitioners who were interviewed, were already aware that the correlation between the duration of the CD phase and the construction costs is weak. They identified the complexity of the project, the extent of the design changes, project type, client characteristics, and others as more influential factors on the CD phase than the construction costs. To improve the quality of CDs, a new guideline for determining an adequate CD phase duration should be studied and developed.

• Land and Housing Review
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• v.2 no.2
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• pp.101-109
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• 2011

Recently, the construction of U-City or of U-City service (U-service) in many kinds of urban development projects becomes the general trend. However, as the construction of U-city comes into the spotlight like the trend of the times, various service constructions are being indiscreetly implemented since it's processed focusing on local specialized projects or local landmark project by a local autonomous entity or an institute in charge being off the original purpose of the improvement of living quality of residents and the efficiency of urban management, which causes a number of problems on the process, maintenance, operation and management of those projects. Therefore, this study is to derive the standard pattern of U-service construction through the analysis of patterns and numbers of U-service and problems during the process of construction in domestic U-City construction case district, and is aimed to suggest the reasonable direction of service construction based on this. 11 projects areas in which data related to U-service are available among U-City construction project areas were selected for the subjects of this study, and it's standardized with 228 detailed unit services that were suggested by U-Eco City R&D and with 11 service domains that are regulated in "the Act of ubiquitous city construction etc.", and it is limited to services that were suggested in U-City case area of which design was completed by July, 2010 based on this. The actual state of various U-service construction is analyzed through case studies as well as reviews on the legal and theoretical concept and the method of pattern classification of U-service, the plan for the standardization (pattern classification) of U-service and the plan for the construction body of service and to share the costs are suggested as the plan to construct reasonable U-service based on this for the method and the procedure of this study For the method to construct U-service, the plan to classify the pattern of U-service into the basic service and additional service is suggested, and whether it has the publicity, whether urban infrastructure is included, whether utilities are included, the body of realization, the recipients, the urgency, the importance and the spreading, etc. are suggested for the index to determine the pattern of service. The method to get the executor of a project to construct the basic service, the method to get the executor of a project to construct the most basic service among the group classification of service and to get a private entity and a local autonomous entity to perform additional service in the future, and the method to construct the whole service and to distribute the construction costs were suggested, and the first one that determines the body of construction after dividing U-service into the basic service and the additional service was evaluated to be the most reasonable one. And the plan to solve the problem that the excessive construction costs of U-service are shifted onto the executor of a project through benefit principle, balanced distribution principle and consultation and mediation between the interested parties was suggested for the criteria to share the costs.

• Journal of the Korean Society for Railway
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• v.10 no.1 s.34
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• pp.23-37
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• 2007

Since 1964, HSR, which was opened in Japan, has had a hoge impact on the world. Historically, HSR has similar characteristics to the Roman Road, which promoted rapid movement and hada great influence on international society as transport infrastructure. Recently the development of HSR has become more rapid because of economic, environmental and external cost concern, emphasizing Environmentally Sustainable Transport(EST). In particular, the external cost has become more important factor for justifying HSR. The successful factors of HSR are high demand and cost minimal construction costs. There are two successful HSR models, the Japanese and the French. The former operates based on high demand oriented and the latter focuses on its minimizing costs. The demand orientated model means HSR carries over 100,000 passengers per day as in Japan and Far East Asian countries. The cost minimized model focuses on lower operation and construction costs as in France. In particular, Germany carries both passengers and freight on HSR. The construction costs in Germany are in between those of Japan and France. In future, Korea, Taiwan and China HSR will follow Japan's successful model because of high population density and concentration of economic activity along railway lines. This paper supports Vickerman's argument that HSR is justified where there is a demand of between 12 million and 15 million railway passenger a year(about 40thousand persons/day) between two urban center. This will be shown in the future in Korea, in Taiwan and China. Finally, this paper reviews that HSR activates at 250km/h for dedicated new lines and 200km/h for upgraded lines. In particular, it is successful in area of high population density and cost minimizing technology.

• KIISE Transactions on Computing Practices
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• v.23 no.12
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• pp.651-659
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• 2017

IT(Information Technology) has focused on infrastructure-technologies in the past but now focuses on IT service. Many companies strive to save costs and improve IT services. For this reason, they strive to implement a good internalization of ITSM (IT Service Management) by developing ITSM systems based on ITIL (Information Technology Infrastructure Library) from the late 2000s. In particular, IT service operations are one of the structure elements of ITIL version 3 and are highly related to the internalization of ITSM. However, in spite-of-the successful implementation of ITSM, the efficiency of IT service management has not improved due to iterative issues. Therefore, this study developed a user-centered training system by defining the iterative issue guidelines and implementing a database. The implemented user-centered training system provided IT service users with regular training services to produce a good solution for iterative issues after connecting the operation part of the ITSM system. Based on the results of this study, we expect that the proposed ITSM system will contribute to efficiently managing IT services by improving the limitations of IT service operation in the ITSM system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.248-258
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• 2020

This study proposed a breakdown structure for maintenance and management technologies under the concept of comprehensive asset management at the life cycle level of infrastructure based on benchmarking with other developed countries. For this purpose, a comparative case study was performed to review and analyze the existing definitions and hierarchies for infrastructure maintenance, repair, and rehabilitation (MR&R) systems under major industrialized countries and South Korea. In accordance with the ratio of maintenance costs to GDP, the U.S., U.K, and Japan were selected to review their systems. The classifications and definitions of MR&R technologies under the laws were analyzed. The result showed that most developed countries differentiate maintenance and repair from improvement and constitute a system centered on preventive maintenance activities. On the other hand, Korea's system for facility management is not definitely classified and still focused on reactive structures, which need to be improved. In this study, as proposed, a breakdown structure established the concept of Maintenance and Management, Maintenance & Repair, and Performance Improvement. Consequently, this study could be used as the basis for the implementation of preventive MR&R activities and reasonable resource allocations from an asset management point of view.