• Advances in concrete construction
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• v.13 no.6
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• pp.423-431
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• 2022

Although the influence of moisture content on the mechanical properties of concrete has been studied for a long time, research related to its influence on the damping and energy dissipation property of concrete structure is still very limited. In this paper, the relationship between damping property and moisture content of concrete using cyclic uniaxial compression is firstly presented, and the mechanism of the influence of moisture content on concrete damping and energy dissipation capacity is analyzed. Based on the experimental research, moisture-related damping and energy dissipation model is proposed. Results show that the dissipated energy of concrete and loss factor increase as the moisture content increasing. The energy dissipation coefficient reflecting the influence of stress level of concrete under cyclic load, decreases first and then increases as the moisture content increasing. The mechanism of moisture-related energy dissipation behavior can be divided into the reactive force of water, the development of the internal micro cracks and the pore water pressure. Finally, the proposed moisture-related damping and energy dissipation model are verified.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1503-1508
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• 2009

The paradigm of urban generation does not lie in physical development/maintenance such as urban redevelopment any more. The paradigm is shifting to balanced activation of administration / management functions including central commerce/business functions, broad culture/tourism functions, international functions and adequate level of residence functions. The urban regeneration project aims to restore functions of cities by physical/environmental, living/cultural and industrial/economical regeneration and is managed differently from existing projects in that it includes multiple sub-projects in it. The overall projects management should be by managing the value sought by the urban regeneration project and multiple other sub-projects. The objective of this study is to present various methods of value management in order to avoid conflicts between various objectives within the said project. It aims to provide the value management methods for decision making by understanding correlatedness between values of various projects and prioritizing them.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.168-172
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• 2009

Shihmen reservoir was started in May 1963. The main purposes of Shihmen reservoir are for agriculture, power supply, flood control and tourism. Shihme Asn dam is an earth dam. Its crown height is 133m above mean sea level, with length 360 m, watershed 763.4 km², and maximum volume 309 million cms. Turbidity in Shihmen dam was severely affected by typhoons Aere (2004) and Masa (2005). Increased deposition after Aere was 28 million cms. Turbidity at Shihmen Canal Inlet is 3000 NTU (Nephelometry Turbidity Unit). Sediment sluicing strategies for downstream channel are demanded. Therefore, diversionary sediment preventing channel is planned in the upstream of Shihmen reservoir. Finally, turbid flow in tunnel channel is bypassed and diverted its flow down to downstream.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.649-657
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• 2009

BTL projects, which has been 3 years since it was carried out in 2008, trigged the controversy on the adequacy in the calculation of disbursement for Government due to such problems as low earning rate and the burden of service level compared with the project suggestion. Thus, the purpose of this study is to offer a suggestion on the calculation system for the purpose of the standardized - expense appropriation by item and database including the antecedent study on the finance model and the feasibility in BTL projects. The system is composed of 4 steps - project management, basic database, an analysis on expense by item and the result, and an analysis on sensitivity, and it is possible to carry out a comparative analysis on single and multi alternatives by variable change along with the ground on expense calculation.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.424-428
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• 2005

As the application of NPM in waste administration branch this paper proposes a new waste management method in order to increase the efficiency of resources and reduce the quantity of waste. First the matrix method is suggested which comprehensively consider and integrate the proposals of different government departments. Moreover the inhabitant's attitude toward the new waste management measures was investigated. Based on the investigation the evaluation function was made, which include three elements: necessary budget, the effect of cost decrease and the environmental burden decrease. The optimal method of budget allocation to maximize social welfare is proposed under the condition of limited budget by the evaluation function. By applying this system further local governments will be able to determine their adequate service level and budget size.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.881-885
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• 2005

Scheduling repetitive projects under limitations on the amounts of available resources (labor and equipment) has been an active subject because of its practical relevance. Traditionally, the limitation is specified as a deterministic (fixed) number, such as 1000 labor-hours. The limitation, however, is often exposed to uncertainty and variability, especially when the project is lengthy. This paper presents a stochastic optimization model to treat the situations where the limitations of resources are expressed as probability functions in lieu of deterministic numbers. The proposed model transfers each deterministic resource constraint into a corresponding stochastic one and then solves the problem by the use of a chance-constrained programming technique. The solution is validated by comparison with simulation results to show that it can satisfy the resource constraints with a probability beyond the desired confidence level.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1009-1016
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• 2022

As environmental concerns grow, people are becoming more aware of energy efficiency, carbon reduction, and sustainable development. Leadership in Energy and Environmental Design (LEED) certification is currently the most widely recognized building environment assessment method connected to energy and the environment worldwide. This study explores trends for six factors (energy and atmosphere, materials and resources, indoor environmental quality, sustainable sites, water efficiency, and innovation in design) to assess four levels of LEED certification (Platinum, gold, silver, and certified) using 11,209 LEED projects in the United States. The study analyzes trends using scores of percentages of maximum points by certification level, ownership type, space type, and climate zones. With the interest in the Environmental, Social, and Governance (ESG) principle on the rise, this study contributes to a better understanding of the trends and future of LEED certification in the built environment sector.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.19-20
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• 2022

Portland Limestone Cement (PLC) is a blended cement using limestone powder as SCMs (Supplementary Cementitious Materials), and is currently regarded as an essential means for achieving carbon neutral in the cement industry. This study was performed to investigate the fresh and hardened properties of cement mortar according to the fineness and replacement ratio of limestone powder. As a result, the compressive strength of mortar used high blaine limestone powder were equivalent level of that of OPC.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.67-68
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• 2021

In this study, Repair mortar was prepared using CNT powder with improved dispersibility and its characteristics were analyzed. As a result of the experiment, the compressive strength and flexural strength were found to be at similar levels compared to Plain without CNT. In addition, as a result of the drying shrinkage test, it was found that the drying shrinkage amount was decreased due to the effect of CNT mixed into the porous material filling the internal pores of the repair mortar.. The Bond strength of the repair mortar was at a similar level regardless of whether CNT was added or not

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.254-255
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• 2021

The urban renewal type redevelopment project is a project to improve the urban environment for the recovery of urban functions and revitalization of commercial districts in commercial and industrial areas. Urban regeneration projects are not progressing smoothly. The urban renewal type is not so for landowners, who require a high level of professional knowledge and experience to carry out smooth projects. In addition, the core part of business conflicts can be seen as the problem of management and disposal methods. Therefore, as landowners, etc. become the actual subjects, the public will take charge of project execution, but all development gains and losses will be attributed to the owner of the land, etc.