• International conference on construction engineering and project management
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• 2009.05a
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• pp.1189-1194
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• 2009

A gutter-shaped U grating is a facility that is installed at the sides of a road to provide pedestrians with a rainwater-free road. The previous studies on this facility focused mainly on the progress of the efforts that are being made to improve its performance and interception efficiency so as to prevent damages in regional areas due to the heavy rains caused by climate change. The studies on its maintenance, however, are still inadequate. Therefore, this study was conducted to analyze and compare the life cycle costs and performance evaluations of the steel and magic gratings, which are installed in apartments. The results of the study show that the replacement period and rate of gratings differ depending on where they are installed. The initial capital investment cost of a magic grating installed at a road where many vehicles pass is quite high, but in terms of its maintenance and entire-life-cycle costs, its total expenses are lower than those of a steel grating. The results of this study are expected to serve as preliminary data for the selection of an adequate grating that is suitable for particular places in the design phase of construction projects.

• Journal of Korean Society for Quality Management
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• v.41 no.3
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• pp.413-421
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• 2013

Purpose: System availability and life cycle cost are often used to evaluate the system performance and is influenced by the operation and maintenance characteristic. In this paper, we propose the method to improve life cycle cost and satisfy the target availability through redundancy allocation. Methods: We consider the redundancy is available at all items in multi level system. Thus, we assume that sub-assembly, module, components can be duplicated. Simulation and genetic algorithm are employed to optimize redundancy allocation. Results: Target availability is higher, the life cycle cost is increased. In addition, the items for redundancy are selected at higher level in multi level system if target availability is higher. Conclusion: We could know that target availability affects the duplication number of items and the selection of redundancy items. For further study, we will consider new optimization algorithms to compare with the proposed GA algorithm and improve optimization performance.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.249-256
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• 1999

This study is intended to propose a systematic procedure for the development of the reliability-based seismic safety and cost-effective Performance criteria for design and upgrading of long span PC bridges. In the paper, a set of cost function models for life cycle cost analysis of bridges is proposed. The total life cycle cost functions consist of initial cost and direct/indirect damage costs considering repair/replacement costs, human losses and property damage costs, road user costs, and indirect regional economic losses. The damage costs are successfully expressed in terms of Park-Ang median global damage indices and damage probabilities. The proposed approach is successfully applied to model bridges in both regions of a moderate seismicity area like Seoul, Korea and a high one like Tokyo, Japan. It may be expected that the proposed approach can be effectively utilized for the development of cost-effective performance criteria for design and upgrading of various types of bridges as well as long span PC bridges.

• Earthquakes and Structures
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• v.25 no.1
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• pp.69-78
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• 2023

Life-cycle performance analysis of a reinforced concrete box section bridge was generated. Moreover, Monte Carlo simulation with important sampling (IS) was used to simulate the bridge material and load uncertainties. The bridge deterioration model was generated with the basic probabilistic principles and updated according to the measurement data. A genetic algorithm (GA) with the response surface model (RSM) was used to determine the deterioration rate. The importance of health monitoring systems to sustain the bridge to give services economically and reliably and the advantages of fiber-optic sensors for SHM applications were discussed in detail. This study showed that the most effective loss of strength in reinforced concrete box section bridges is corrosion of the reinforcements. Due to reinforcement corrosion, the use of the bridge, which was examined, could not meet the desired strength performance in 25 years, and the need for reinforcement. In addition, it has been determined that long-term health monitoring systems are an essential approach for bridges to provide safe and economical service. Moreover the use of fiber optic sensors has many advantages because of the ability of the sensors to be resistant to environmental conditions and to make sensitive measurements.

• Journal of KIBIM
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• v.5 no.2
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• pp.34-45
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• 2015

As buildings become larger and more complicated, construction costs have increased with a considerable effect on buildings' Life Cycle Cost (LCC). However, there has been little consideration on economic aspects in the selection of construction materials due to limited information on the materials and dependency in architects' experience and inefficiency in cost estimation, causing design changes, increase in maintenance cost, difficulty in budgeting, and decrease in building performance. To solve these problems, this study proposed a BIM-based material selection model which reflects the comprehensive economic efficiency of building materials. Our cost prediction model can estimates the material-related cost during the entire building life cycle. Furthermore, we implemented the proposed model in connection with BIM, which can analyze and compare LCC by material. Through the validation of the model, we could confirm the necessity of LCC-based material selection in comparison with the conventional cost-centered material selection.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.636-642
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• 2009

The application of LCC-techniques is being introduced at the on-going procurement programs of various techniques. LCC-techniques have the common characteristic that all are designed to motivate contractors to design, manufacture and deliver equipment with lower life cycle costs. You may believe that savings may be in the acquisition cost component of life cycle costs. However, primary emphasis is generally on reducing and controlling operating and support costs by transferring more responsibility to the contractor for equipment operating and support cost performance. It has been found that life cycle cost procurement provisions must be individually tailored to each program. In this study, the currently identified LCC procurement techniques including a variety of LCC incentive provisions are introduced. Moreover, verification method, a procedural issue and incentive to application of LCC-techniques are examined.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.2
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• pp.134-142
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• 2002

LCC (Life-Cycle Cost) analysis is a practical method and a guideline for evalua-ting the economic performance of building service systems. By using the LCC analysis, the most cost-effective design decision can be made, which has the lowest LCC during the project study period among the various design alternatives. The present case shows an example of appro-priate use of the LCC analysis, by demonstrating the procedures of decision making among at-tarnative building HVAC systems at community center and congress hall of a local government.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1463-1467
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• 2009

Construction projects are vulnerable to diverse internal and external factors, requiring systematic and consistent performance management along the entire life cycle of a project. In particular, urban renewal projects have a range of performance measures, including policy reconciliation and permits, project development, project financing, design, construction, and occupancy and maintenance. This requires a program-level megaproject approach, which integrates each stage of a project as well as variety of stakeholders' interests in pursuing a project from different perspectives. However, previous research on performance management has focused especially on the limited scopes of factors, including cost, quality, and schedule at the project level or on financial factors at the firm level. Given the lack of current approaches, this study suggests an integrated and systematic performance management scheme to control urban renewal megaprojects at the broadened perspectives of the program level. To this end, this study adopts the balanced scorecard approach and elicits key performance indices associated with various project configurations. Finally, an algorithm is presented for quantitatively assessing the level of performances along whole life cycle of urban renewal megaprojects.

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.239-246
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• 2015

Enforced environmental regulations call for extending the domain of manufacturers' responsibility to the entire product life cycle. To comply with the environmental regulations, manufacturers have constructed reverse logistics networks to re-collect their leftover waste for recycling consumed resources. However, the operational activities associated with storage, loading and transportation processes within the networks inevitably impose environmental burdens. Particularly, the transportation process largely influences environmental performance due to perpetual uses of transportation vehicles. Therefore, there is a need to develop an environmentally-conscious transportation model that can efficiently manage the uses of transportation vehicles. Additionally, it is vital to analyze its significances of environmental performance to compare quantitatively it with existing models. This paper proposes a transportation model for improving environmental performance in a reverse logistics network. This paper also presents a case study to perform its comparative analysis using Life Cycle Assessment that evaluates potential environmental impacts of a product system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.854-857
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• 2008

Wireless sensor consists of an internal power source which has limited life time. Several MAC protocols have exploited scheduled sleep/listen cycles to conserve energy in sensor networks. Duty cycle is a user-adjustable parameter in low duty cycle MAC protocols, which determines the length of the sleep period in a frame. The sire of duty cycle has direct effect on the Performance of MAC Protocols. In this Paper, we simulated TEEM (A Traffic Aware, Energy Efficient MAC) and S-MAC in NS-2 with different duty cycle values and analyze how duty-cycle effects on the performance and energy consumption of both the protocols.