• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.5
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• pp.1589-1597
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• 2014

For several decades, economic growth has achieved in the aspect of productivity and effectiveness not environmental friendly. As a result, global warming is a major agenda to solve. Therefore, global effort to sustainable development has been adopted like UNFCCC and Kyoto protocol that aimed to reduce greenhouse gas. However, the construction industry has only focused on applying techniques for using less energy sources not monitoring sustainable construction and development. Therefore, this study developed a tool for monitoring greenhouse gas emissions in construction industry. The proposed system evaluates and estimates BAU (Business as usual) for each phase of a construction project. For this purpose, analyzed the greenhouse gas emission factors coincide to life cycle of a construction project. The scope of monitoring is determined according to data availability and emission factor. Then, the system framework is developed and the calculation logic is proposed the system features provide comparison between the emission estimates for eco-friendly design and the actual emission of construction and operation phases. The system would be utilized as a tool for supporting to green construction realization and green construction performance evaluation.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.125-133
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• 2016

The Project Risk Management is intended to result in the effective management by identifying in advance and mitigating all significant risks including project risks and opportunities during the entire project life cycle - from project inception to completion of construction. It is impossible to predict an exact budget and construction duration before finishing a project. So, Washington Department of Transportation mandates that workshop-based risk management is conducted for projects over specific cost. However, the domestic construction sites have depended on numerical risk analysis without any workshop and efficient risk management have not made. Therefore, in this study, we propose the effective risk management using the RBES program which is very useful for workshop-based risk management and pre & post mitigation, by workshop-based risk management techniques. This proposed risk management approach is applied to a domestic 'A' river recovery project. It is concluded that we may expect the effect to mitigate the total cost overrun problem and the construction duration delay effect in the project by identifying significant risks and by preparing effective risk mitigation strategies.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.26-37
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• 2009

Ministry of Land, Transportation and Marine Affairs(MLTM) has implemented Construction CALS project for improving productivity of construction industry and for making construction project management efficient by responding to informatization and knowledge base society in 21st century. CALS has beeb applied successfully to projects form MLTM, however, the outcomes of Construction CALS hasn't been recognized. In addition, there is no way to find how high the level of Construction CALS is when it is compared with other SOC informatization projects. This study found out the informatiziation level of Construction CALS by using the evaluation index proposed in the former study, and by comparing with other sectors. The evaluation on the level was implemented in the three parts such as informatization infrastructure(network, hardware, standardization, data, informatization, informatization security), informatization utilization(information usage, IT performance), and informatization support(informatization goal, organization of informatization, informatization investment, informatization education), and then, this evaluation was compared with "Assessment for level of industry information system", "Assessment for level of small and midium sized industry information system", and "IICI(Informatizaion Index for the Construction Industry)". With the result from the comparison, this study produced superior factors and inferior factors for each sector. These results are expected to be useful for prioritizing budget allocation by finding out the informatization level of Construction CALS.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.111-118
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• 2009

This study is to analyze the performance of SWH(Solar Water Heating) and GSHP(Ground Source Heat Pump) systems by evaluating their energy efficiency and LCC(Life Cycle Cost) as being applied to the OO hall as a selected building in the Army. The OO hall, used as bathrooms, dining rooms, accommodations and offices, has reinforced concrete structure system with three floors above the ground and one underground, and its total floor area is approximately 2,917$m^2$. Two energy simulations are conducted to predict the yearly cooling and heating energy of the selected building: One is for analysis of an air-conditioning energy consumption using the e-Quest program, and another is for two new-renewable energy facilities as a water heating source using the RETScreen. The installed capacity of two new-renewable energy facilities is determined according to the 5% level of total standard construction cost. As a briefly result, SWH system is more energy-effective than GSHP system. Considering the break-even point, it is expected that SWH can take only 3 years 11 months to pay for itself in savings while the investment of GSHP can be recovered in more than 16 years 6 months.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.715-722
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• 2020

This paper proposes a design verification method based on system dynamics for offshore separation systems. Oil and gas separation systems are key components of offshore oil platforms; these systems determine the competitiveness of engineering, procurement, and construction (EPC) projects, especially in terms of added value. However, previous research on design verification has been limited to the process and deliverables of design. To address this, the study aims to develop a comprehensive design verification method and the associated functions from the perspective of project management, for the entire project life-cycle of offshore structures. The proposed methodology for design verification is expected to contribute toward effective and detailed designs as well as improve the competitiveness of EPC companies in constructing of shore structures during the early design stages. We first analyzed the separation system of the FPSO using the design verification method adopted by advanced countries and compared it with the system dynamics process formalized as ISO 15288. Subsequently, a tailored process for the design verification of the offshore structure was derived. It is shown that the proposed design verification method can be applied to the front-end engineering design process of of shore structures. Moreover, it can contribute toward the successful performance of offshore projects in the future and also minimize design changes and critical risks during the construction of these offshore structures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.3602-3610
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• 2013

The risk of failure in the development of modern weapon systems has been increasing as the demand on the capability and the resulting complexity of the weapons on the war fields are increasing drastically. The analysis of failure has indicated that the main causes can be the following: one is attributed to the unsatisfaction of the system operation concept; and the other is the use of premature technology. As such, DAPA in Korea is urging that the weapons systems development should meet the required operational capability (ROC) as a critical performance requirement. On the other hand, an approach to risk management is to use the technology readiness level (TRL) assessed for each individual technology alone. However, the method of TRL cannot assess the effect of integration between technologies and cannot be performed at system level, which is crucial to systems development. In order to improve the shortfalls, a concept of system readiness level (SRL) has been studied by introducing the technologies integration and also some forms of analysis of advanced degree of difficulty studied separately, but no model considering both of two reported yet. In this paper, under the framework of meeting the ROC, an improved SRL assessment model is presented, which is also considering the advanced degree of difficulty simultaneously. The application of the improved assessment method is discussed in connection with the life cycle of the weapon systems development in conformance with the ROC of DAPA.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.784-793
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• 2017

A two-axis gimbal-type X-band antenna mounted on an observation satellite can efficiently transmit high-capacity image data to a ground station regardless of both the satellite position and the orbital motion. However, this X-band antenna induces unnecessary micro-jitter which can degrade the image quality of the high-resolution observation satellite. Therefore, to achieve the high-resolution image quality from the observation satellite, micro-jitters have been required to be isolated. In this study, to resolve aforementioned drawback, we proposed blade gear using a shape memory alloy (SMA) applied to azimuth stage of X-band antenna. To investigate the rotational basic characteristics of the proposed SMA blade gear, we performed rotational static loading test. Futhermore, to evaluate the cycle to failure of the gear, accelerated life test was conducted. The temperature test was conducted to confirm rotational basic characteristics at various temperature conditions. To verify the isolation performance for micro-jitter, we performed micro-jitter measurement test.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.2
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• pp.141-149
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• 2015

In the fabrication of electronic circuits used in electronic products, molybdenum thin films are deposited on semiconductors to prevent oxidation. During the deposition, the presence of a particle or dust at the interface between the thin film and substrate causes the decrease of adhesion, performance, and life cycle. In this study, a damage measurement targeting two kinds of glass substrate, with and without particles, was performed in order to measure the change in the molybdenum thin film deposition area in the presence of a particle. Clean and dirty molybdenum thin film specimens were fabricated and directly deposited on a substrate using the sputtering method, and a reflection-type digital holographic interferometer was configured for measuring the damage. Reflection-type digital holography has several advantages; e.g., the configuration of the interferometer is simple, the measurement range can be varied depending on the magnification of a microscopic lens, and the measuring time is short. The results confirm that reflection-type digital holography is useful for the measurement of the damage and defects of thin films.

• 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.

• Journal of the Korea Institute of Building Construction
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• v.10 no.5
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• pp.45-54
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• 2010

Recently more and more construction projects have become high-rise, complex and intelligent. Accordingly, such projects require an integrated management system for tasks, with a lean approach to construction with work processes for management and productivity. In particular, Construction Information Technology (CIT) fields are concerned with Building Information Modeling (BIM), which represents the process of generating and managing building data during its life cycle. Constructability research has progressed for the project goal which is a cost-time-quality of optimization by integrated construction knowledge and experience. However, the current constructability process has not been performed efficiently, as the existing 2D drawings and papers lack consistent and accurate information, it is difficult to share the contents of work, and the use of information is inefficient. This study proposes that the reformation and enhancement of BIM-based constructability work process can lead to brilliant performance in the framework of the construction phase through achieving collaboration between the design team and the workers at the site.