• Proceedings of the KSR Conference
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• 2011.05a
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• pp.221-225
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• 2011

The railway system consists of many items such as sub-systems, equipments and parts to accomplish the required function. Also the railway system is very complex system that these items are connected with interface among items. According with this complexity, the process of system engineering is applied to the construction of new railway project to manage systematically. In addition, the research about system engineering is progressing in recent. The RAMS management is one part of system engineering, and is to assure the required safety and performance. Also, this RAMS should be managed through system life cycle. This paper show the case study of management of RAMS during construction and operation phase in respect of system life cycle. As a result of this research, the best way of RAMS management based on system engineering in operation phase for railway system is suggested.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1282-1288
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• 2011

Recently, the demand regarding reliability and safety of the railroad are increased as built to high-speed railway and Driverless LRT systems. Accordingly, effective management of construction projects is being applied, with the introduction and use of PMIS computerized systems. Due to the construction of railways, from the start of PMIS research planning, design, procurement, to construction and commissioning, various expertise is being carefully gathered, and by integrating it into the unified budget ideas and processes, rational, efficient, organized, and manageable financial plans are developed for the computerized system. However, the current PMIS does not take into account the life-cycle. Therefore, this study is to bring attention to the BIM smart BOM-based configuration management for life-cycle through the consideration for railway construction project management.

• 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.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.396-407
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• 2002

New Electric Multiple Units that will be released in the rolling stock market are required to meet regulations of reinforced safety and conveniences for passengers. For those reasons, Vehicle purchasing cost to be increased will be unavoidable. However, The reduction of operating cost by employing effective and efficient design on the EMU at initial phase will be expected. Hence, Vehicle purchasing shall be determined to take into consideration of purchasing cost vehicle at first stage and operation cost appropriately. In order for introducing method to presume such costs, this document will show Life Cycle Cost on vehicle and its applicability.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1145-1146
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• 2008

Failures of equipments are linked directly to extensive damages of human lives or financial losses from the increasing uses of railway signaling equipments utilizing computers. Then safety organizations have to establish for guaranteeing safety during the system life-cycle. In this paper, we examine the relationship between railway signaling standards and other safety standards for safety meaning establishment.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.201-206
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• 2006

As the seriousness of the global environment is gaining increasing our attention recently, studies on application of LCA(Life Cycle Assesment) to ship are being carried dynamically in various industry fields. This study examined general outline about local and international application cf LCA to ship. First of all, international background for the appearance of LCA and its general meaning are introduced. The state-of-the-art for its application to ship will be also explained. Finally, domestic study methodology for application of LCA to ship were suggested.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.7-12
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• 2000

The automatic turbine startup system provides turbine control based on thermal stress. During the startup, control system monitors and evaluates main components of turbine using damage mechanism and life assessment. In case of valve chest, the temperature of inner/outer wall is measured by thermo-couples and the safety of these values are evaluated by using allowable ${\Delta}T$ limit curve during the startup. Because allowable ${\Delta}T$ limit curve includes life assessment, it is possible to apply this curve to turbine control system. In this paper, low cycle fatigue damage and combined rupture and low cycle fatigue damage criterion proposed for yielding the allowable ${\Delta}T$ limit curve of CV(control valve) chest. To calculate low cycle fatigue damage, the stress analysis of valve chest has peformed using FEM. Automatic turbine startup to assure service life of CV was achieved using allowable ${\Delta}T$ limit curve.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.1-6
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• 2002

The automatic turbine startup system provides turbine control based on thermal stress. During the startup, control system monitors and evaluates main components of turbine using damage mechanism and life assessment. In case of valve chest, the temperature of inner/outer wall is measured by thermo-couples and the safety of these values are evaluated by using allowable △T limit currie during the startup. Because allowable ΔT limit curve includes life assessment, it is possible to apply this curve to turbine control system. In this paper, low cycle fatigue damage, combined rupture and low cycle fatigue damage criterion were proposed for yielding the allowable ΔTf limit curve of CV(control valve) chest. To calculate low cycle fatigue damage, the stress analysis of valve chest has been performed using FEM. Automatic turbine startup to assure service life of CV was achieved using allowable ΔT limit curve.

• Smart Structures and Systems
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• v.12 no.2
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• pp.209-233
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• 2013

With an annual growth rate of about 30%, wind energy systems, such as wind turbines, represent one of the fastest growing renewable energy technologies. Continuous structural health monitoring of wind turbines can help improving structural reliability and facilitating optimal decisions with respect to maintenance and operation at minimum associated life-cycle costs. This paper presents an integrated monitoring system that is designed to support structural assessment and life-cycle management of wind turbines. The monitoring system systematically integrates a wide variety of hardware and software modules, including sensors and computer systems for automated data acquisition, data analysis and data archival, a multiagent-based system for self-diagnosis of sensor malfunctions, a model updating and damage detection framework for structural assessment, and a management module for monitoring the structural condition and the operational efficiency of the wind turbine. The monitoring system has been installed on a 500 kW wind turbine located in Germany. Since its initial deployment in 2009, the system automatically collects and processes structural, environmental, and operational wind turbine data. The results demonstrate the potential of the proposed approach not only to ensure continuous safety of the structures, but also to enable cost-efficient maintenance and operation of wind turbines.

• International Journal of Computer Science & Network Security
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• v.23 no.3
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• pp.31-48
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• 2023

The popularization of smart devices and subsequent optimization of their sensing capacity has resulted in a novel mobile crowdsensing (MCS) pattern, which employs smart devices as sensing nodes by recruiting users to develop a sensing network for multiple-task performance. This technique has garnered much scholarly interest in terms of sensing range, cost, and integration. The MCS is prevalent in various fields, including environmental monitoring, noise monitoring, and road monitoring. A complete MCS life cycle entails task allocation, data collection, and data aggregation. Regardless, specific drawbacks remain unresolved in this study despite extensive research on this life cycle. This article mainly summarizes single-task, multi-task allocation, and space-time multi-task allocation at the task allocation stage. Meanwhile, the quality, safety, and efficiency of data collection are discussed at the data collection stage. Edge computing, which provides a novel development idea to derive data from the MCS system, is also highlighted. Furthermore, data aggregation security and quality are summarized at the data aggregation stage. The novel development of multi-modal data aggregation is also outlined following the diversity of data obtained from MCS. Overall, this article summarizes the three aspects of the MCS life cycle, analyzes the issues underlying this study, and offers developmental directions for future scholars' reference.