• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1471-1479
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• 2015

A major portion of the capital costs in the present day power transmission systems are due to the cost of equipment and construction process. Transmission utilities in the recent years are drawing greater attention towards performing life cycle costing studies for cost management and decision making. However, the data involved in these studies are highly uncertain and the effect of these uncertainties cannot be directly included in the study process, resulting in inaccurate solutions. Interval mathematics provides a method for including these uncertainties throughout the cost analysis and provides final solution range in the form of intervals. In this regard, it is essential and extremely important that significant research has to be carried out in understanding the principles of life cycle costing methodology and its applicability to cost analysis of transmission lines along with uncertainties involved in the cost assessment process. In this paper, economic analysis of power transmission lines using interval mathematics has been studied. Life cycle costing studies are performed using net present value analysis on a range transmission lines used in India and the results are analyzed. A cost break even analysis considering right of way costs was carried out to determine the point of economy indifference.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1523-1529
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• 2018

Electric vehicles that are currently in operation are being produced domestically. Therefore, there is no great difficulty in receiving or repairing the failed parts or in the overall repair. On the other hand, most of the electric locomotives are manufactured by introducing the parts and technology of foreign vehicle manufacturers. In this paper, conducted a study about life cycle cost analysis of developed auxiliary power unit in 8200 series electric locomotive and suggested cost down method. This confirms the economic benefits of the developed products of the auxiliary power supply compared to the existing products. In addition, a sensitivity analysis of MTBF was conducted to suggest a life cycle cost down method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.259-260
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• 2016

Recently, world-wide focusing on the interest for the reduction of greenhouse gas emissions associated with climate change and global warming, South Korea also has set up a national greenhouse gas reduction target and action plans seeking to achieve them. In particular, in the construction area, to encourage green building certification of the building and carbon labeling acquisition of building products, in order to reduce the environmental impact caused by the industrial activities have been in steady efforts. Therefore, this study estimates the life cycle carbon footprint of building construction materials applied to carbon emissions reduction technology and analyzes the results. Through the CO₂ emissions analysis in construction phase and maintenance phase of the building, it provides basic resource for future research expansion and establishes a step-by-step whole life cycle carbon emissions reduction plan in new construction and existing buildings.

• 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.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.593-598
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• 2016

Static tests and low-cycle fatigue tests were conducted to analyze the characteristics of the bellows for LNG vessels according to the forming methods. The cycle life of bellows was tested based on the specified cyclic life, 80000 cycles, to analyze the difference in characteristics between pre-and post-test data by measuring the strain and stress of each convolution of formed bellows. The low-cycle fatigue test was conducted using a strain gauge that was attached to the convolution of bellows. Formed bellows were placed on the structural test device which was equipped with a hydraulic system and was capable of moving in the x-y direction. Data was measured and processed by a multi recorder. Through the static test and low-cycle fatigue tests results, the difference between the cycle life of bellows formed by mechanical methods and of those formed by hydraulic methods was investigated. Moreover, the cause of difference in cyclic life according to forming methods was performed.

• ALGAE
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• v.33 no.2
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• pp.191-203
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• 2018

Fragilariopsis cylindrus is one of the most successful psychrophiles in the Southern Ocean. To investigate the molecular mechanism of biomineralization in this species, we attempted to synchronize F. cylindrus growth, since new cell wall formation is tightly coupled to the cell division process. Nutrient limitation analysis showed that F. cylindrus cultures rapidly stopped growing when deprived of silicate or light, while growth continued to a certain extent in the absence of nitrate. Flow cytometry analysis indicated that deprivation of either silicate or light could effectively arrest the cell cycle of this diatom species at the G1 phase, suggesting that synchrony can be established using either factor. Fluorescence labeling of new cell walls was faintly detectable as early as approximately 6 h after silicon repletion or light irradiation, and labeling was markedly intensified by 18 h. It is revealed that the synthesis of girdle bands begins before valve synthesis in this species, with active valve synthesis occurring during the G2 / M phase. Expression profiling revealed that selective member(s) of the F. cylindrus SIT genes (FcSIT) respond to silicate and light, with a different set of genes being responsive to each factor. The Si / light double depletion experiments demonstrated that expression of one FcSIT gene is possibly correlated to transition to G2 / M phase of the cell cycle, when the valve is actively formed.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.546-554
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• 2023

The cyclical behavior of Alloy 617 was examined at 25 ℃ and high temperatures of 800, 850, 900, and 950 ℃ in air to obtain its fatigue life curves. The specimens tested at 25, 800, and 850 ℃ cyclically hardened, whereas those tested above 900 ℃ cyclically softened from the first cycle, that is, their fatigue life was reduced at high temperatures owing to loss of strength. Parameters of the typical Coffin-Manson-Basquin relationship were determined for each test temperature. Interestingly, no significant difference in fatigue life was observed for the specimens tested in the range of 800-950 ℃. Owing to the similarity in fatigue life, we determined fatigue strength and fatigue ductility exponents that could be applied for this temperature range. The parameters obtained were close to the universal slopes, although the fatigue ductility exponent was slightly different. The proposed fatigue life curves were compared with those presented in ASME code.

• Clean Technology
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• v.20 no.3
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• pp.241-250
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• 2014

In this study, performance and environmental characteristics of cyclone vacuum cleaners are analyzed and product improvement methods are investigated to minimize environmental effect of the cleaners using the result. A simplified LCA method is used to analyze environmental characteristics of the cyclone vacuum cleaners. Two cyclone vacuum cleaners with similar specifications are chosen for the experiment. Typical characteristics of cyclone vacuum cleaners such as energy consumption, suction force, noise and temperature are measured and compared. Most environmental effect was caused by the energy consumption in use phase of life cycle. Some ideas are created to reduce energy consumption of the vacuum cleaners in use phase like installing baffle, and methods to extend exchange period of filter. It is analyzed how recyclability rate of vacuum cleaners could be improved to reduce the environmental effect in whole life of the vacuum cleaners.

• Journal of Korean Society of Transportation
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• v.18 no.1
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• pp.7-15
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• 2000

물류에서는 재화 또는 정보의 흐름이 매우 중요하다. 그 동안 우리나라에서는 물류시스템을 물리적인 시설로 간주 시설의 공급에만 관심을 기울여 왔다. 그 결과 물류활동을 지원할 수 있을 만한 정보시스템의 구축이 충분히 이루어지지 못하였다. 본 연구에서는 화물운송을 위주로 한 화물유통체계의 합리화 방안을 모색하기 위하여 교통부분과 밀접한 연계를 갖는 첨단화물운송체계의 도입효과를 논의하고 Life-Cycle Cost의 개념을 이용하여 첨단화물운송체계의 시스템 대안을 평가하였다. 분석결과 노변 통신시스템을 이용한 시스템의 구성이 중장기적으로 유리한 것으로 평가되었다. 이는 통신비의 부담이 시설의 유지보수비의 부담보다 크기 때문이다. 그러나 노변통신시스템시설은 표준화 등의 문제로 아직 적용에 문제점들이 많으며 낙뢰 등 비용산정에 포함되지 못한 유지보수의 추가비용이 발생할 소지가 크다. 그러므로 교통시설의 특징에 따라 두 접근방식을 혼용하는 방안이 검토되어야 한다.

• Journal of Information Technology Applications and Management
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• v.19 no.2
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• pp.135-147
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• 2012

Software architecture, as a blueprint for the system, should provide a robust foundation for design, implementation, and maintenance, for communication and documentation, and for reasoning about important system properties. Software architecture plays a central role during the whole software life-cycle. There are so diverse definitions of the software architecture, however, and there is no common agreement about what software architecture is. Examining 27 'published' definitions of software architecture, we synthesize an extensive model on the essential elements of software architecture, which consists of components, interaction among components, well-formed structure, reasons, and various perspectives. Further, we explore the possibility of unifying diverse software architecture definitions into a software architecture life-cycle model.