• Steel and Composite Structures
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• v.43 no.4
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• pp.465-481
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• 2022

This paper presents a comprehensive integrity assessment of welded structural components, including uniform high- and low-cycle fatigue assessment of welded plate joints and fatigue-induced fracture assessment of welded plate joints. This study reports a series of fatigue and fracture tests of welded plate joints under three-point bending. To unify the assessment protocol for high- and low-cycle fatigue of welded plate joints, this study develops a numerical damage assessment framework for both high- and low-cycle fatigue. The calibrated damage material parameters are validated through the smooth coupon specimens. The proposed damage-based fatigue assessment approach describes, with reasonable accuracy, the total fatigue life of welded plate joints under high- and low-cycle fatigue actions. Subsequently, the study performs a tearing assessment on the ductile crack extension of the fatigue-induced crack. The tearing assessment diagram derives from the load-deformation curve of a single-edge notched bend, SE(B) specimen and successfully predicts the load-crack extension relation for the reported welded plate joints during the stable tearing process.

• Environmental and Resource Economics Review
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• v.27 no.2
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• pp.261-286
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• 2018

This paper evaluated the economic feasibility of the life extension of Kori unit 1 and Wolsong unit 1 according to the types of the nuclear power plants (NPPs) and the life extension period comparing to the levelized costs of energy (LCOE) of the new NPPs, coal-fired plants (CFPs), and combined cycle gas turbine (CCGTs) which proposed in the $7^{th}$ Basic Plan for Electricity Supply and Demand. The economic feasibility of the life extension of NPPs using LCOE method is affected by the types of NPPs, lifetime extension periods, discount rate, and capacity factor. According to the analysis results, the pressurized light water reactor (PWR) is more economical than the pressurized heavy water reactor (PHWR). Comparing the economical efficiency between the life extension of NPPs and other alternatives, the operation of the PWR for 20 years is more economical than the one of new NPPs and CFPs. However, 20 years of life extension of PHWR is more economical than the CCGTs, but less economical than new NPPs and CFPs. In summary, the 20 years of life extension of the NPPs seems to be more, especially for the PWR, which is more cost effective than other generation alternatives. Therefore, the government policy of the life extension of NPPs need to be a selective approach that simultaneously considers both safety and economics rather than closing all NPPs.

• Journal of Agricultural Extension & Community Development
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• v.10 no.1
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• pp.1-14
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• 2003

This study proposes strategies for information requirements analysis (IRA) for successful agricultural management information system (MIS) development. The study frist defines IRA based on literature review and emphasizes the importance of IRA by its position in SDLC (System Developments Life Cycle). Then, the study reviews fifteen cases of agricultural MIS development projects appeared in the report of all the MIS related ARPC(Agricultural R&D Promotion Center) projects from 1995 to 1998 and finds that IRA is not properly performed in most of the projects. Finally, this study proposes seven strategies for IRA for successful agricultural MIS development based on the finding of this study and those from the literature related to IRA methods.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.515-519
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• 1997

The purpose of this study is to reduce the fast neutron fluence at the reactor pressure vessel(RPV) and to provide a basis for plant-life extension. In this study, different neutron absorbers were employed in the core outer assemblies of Kori Unit 1 Cycle 14. The modified assemblies were used to calculate fast neutron fluence at the RPV and to evaluate reduction of outer assembly power and total power in core. By comparison with the case of no suppression fixture, the fast neutron fluence of a case with two rows stainless steel around the assembly with natural uranium pins is decreased by 85.8%. It is noted that the modification of outer assembly is more efficient than the previous low leakage loading pattern (LLLP) applied to Kori Unit 1. Also, compared fast neutron fluence in Cycle 1 with Cycle 14, fast neutron fluence at the RPV between Cycle 1 and Cycle 14 is not significantly different. It is found that LLLP applied to the Kori Unit 1 has not contributed to fast neutron fluence reduction at the RPV.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.122-129
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• 2004

In plastic working, as working becomes speedy, automatic and working condition deteriorates, the increase of forging working has been remarkable. Therefore, we need the estimation of mold lift in detail, in order to counterplan of effective mold life extension. In this study, on the SKH51, mold steel which is forged by cold working and the KCW1, tool steel of low alloy, we estimated mold life on the base of FEM analysis and investigated mold lift by low cycle fatigue test. Also, this paper suggested a new method of estimation of mold lift.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1103-1107
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• 2016

The automatic tensioning device of the catenary system constantly maintains the tension of the trolley wire by absorbing the variations due to the elasticity of the line caused by temperature variation. The tension plays an important role in affecting the electric motorcar operation directly. This paper suggests the methodology of the life cycle extension and the maintenance of the automatic tensioning device by means of performance diagnosis of the pulley type automatic tensioning device which has been commonly used for the electric railway system. Through conducting performance diagnosis and comparative test for the wornout pulley type automatic tensioning device by replacing the components such as the bearing and the bearing shaft without replacing all the assembly, the tensioning device is analyzed whether it is properly functioned. Provided that the maintenance regulation is reinforced so as to implement the bearing replacement through periodical precise inspection along with random check-up inspection which is now carried out by the operating organizations, it is ensured that the life cycle extension and the reduction of maintenance cost of the tensioning device could be achieved.

• Journal of KIISE:Software and Applications
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• v.30 no.5_6
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• pp.503-514
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• 2003

In conventional development methodologies, requirements are considered to be not changing after analysis phase, and requirements specifications are used for the next step system design purpose. But in the real world, requirements can be changed and modified throughout the development life cycle according to end-user's more understanding about the target system, new IT technologies, changes of customer environment and market situation, and so on. So there needs a requirements change management process that can extend requirements management over the entire development life cycle and can support managing changes to the requirements after design phase. In this paper, a requirements change management process that can be integrated into conventional development methodologies is proposed to support the extension of requirements life cycle and managing changes to the requirements after design phase. This process was evaluated through an verification test with a widely used development methodology‘MaRMI’.

• Journal of Fashion Business
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• v.27 no.4
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• pp.1-20
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• 2023

This study proposes the practical design elements of sustainable fashion by understanding the values of the MZ generation and analyzing the design characteristics that can extend the life of clothing. The theoretical concept of sustainable fashion through previous studies was reviewed and in-depth interviews were conducted with the MZ generation on "design characteristics of clothes that they have actually used for a long time." The result was drawn by approaching the constant comparison method through the qualitative methodology. As a result of the study, the design characteristics of clothes that can be worn for a long time are as follows. First, simple design pursues simplicity that is not excessive to the essential characteristics of clothes. Second, sturdy material is durable and not easily damaged. The clothing storage method and laundry method were also factors that could extend the life of the garment. Third, emotional design is a design that fits well with your mood and body type and gives a special meaning to your emotions. This study is meaningful in suggesting elements necessary for extending the life cycle of clothing and providing basic data that can be applied to the practical design steps of the fashion industry.

• Journal of the Korea Fashion and Costume Design Association
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• v.19 no.2
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• pp.1-14
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• 2017

The consumption trend of fashion in modern industrial society is developing from the rapid changes, and the lifespan of fashion products becomes shorter due to the various industrial wastes. Due to the attitude change caused by the ethical consumption consciousness and environment awareness, the up-cycle fashion products got to receive attention, and it is in the limelight as a new trend to realize the sustainable fashion products in the domestic and foreign fashion. The purpose of this study lies in drawing the expression characteristics by investigating and analyzing the cases of each type on the fashion bag products of up-cycle brand, and contributing to the diversification of product family fitting to the characteristics of fashion bag product of up-cycle brand, systematic strategies of up-cycle fashion products, and activation of up-cycle fashion market. In research methods, the theatrical researches were conducted centered the relevant domestic literature materials, preceding papers, etc., which ran paralleled with the actual case analysis study. Through the preceding research and websites related to selected products, websites of up-cycle companies, relevant books, related articles, etc., the expression characteristics of up-cycle fashion bag products were drawn. The results of this study are as follows: First, as it has the feature of historicality, the designs can be created by containing the designer's story, story of materials, and consumer's story. Second, since it has the characteristic of sustainability, the application of manufacturing process and materials, extension of product life, conversion of original material's function, etc. can be sustainable. Third, as it's a trait of scarcity, all products may be produced by hand, and it can have the specialty which the original materials have. Fourth, since it has an eco-friendly trait, even while saving the original materials, the aesthetic needs could be met according to the consumers' continuous demand.

• Korean Journal of Computational Design and Engineering
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• v.13 no.5
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• pp.352-361
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• 2008

Architectural design work depends on information made from earlier phases such as feasibility study, planning, and conceptual design. This design guideline information includes design objectives, requirements, and constraints made by decision-making, and has great influence on various works of latter phases of design process. Despite of this cognition, however, the lack of design guideline information management still remains as one among the critical issues in design area. Design tools with design guideline information do not also address the issue of interoperability throughout the life-cycle of buildings. The purpose of this research is to propose a method for design guideline information management by using the IFC technology and IFC Property set (Pset) extension mechanism. The method comprises defining and mapping the practically used design guideline items and extensible IFC data model, and includes the management of relationships that exist between design guideline information and design model in the IFC data model.