• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.673-678
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• 2005

IMO adopted ' International Convention for The Control and Management of Ships' Ballast Water and Sediments ' on February 13th 2004. According to this convention, a ballast water treatment system should be installed in all ships obligatorily up to a standard date. When the system is installed, economic propriety should be considered. The economic propriety analysis examines the profit of a relevant project which can be presented by a equation, (Profit) = (income) - (expense) - (tax). However, the ballast water system is not for the profit during the life cycle but for the satisfaction of the regulation. Therefore, the expense should be minimum against the profit. This study presents the LCC(Life-Cycle Cost) analysis for economic evaluation of several ballast water system of foreign products.

• Journal of the Korean Society for Railway
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• v.17 no.5
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• pp.373-380
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• 2014

With a view to the commercialization of the Korean automatic variable-gauge bogie in the Eurasia railway system, the aim of this research was to perform an economic analysis concerning the possible introduction and operation of this bogie at the present time. For this purpose, we compared the possible types of freight connection service for container transportation, transshipment and the gauge-adjustable system, estimating the total life-cycle cost (LCC) incurred by each system, depending on type and quantity, over the whole process of acquisition, operation, maintenance and disposal. Based on this, we presented a case-by case analysis. Furthermore, in estimating economic feasibility, we analyzed the cost-benefit ratio taking into account not only the objective LCC, but also the reduced time required for the gauge-change and customer convenience. After estimating the LCC and analyzing the cost-benefit ratio of the respective systems, we demonstrated the economic superiority of view of the gauge adjustable system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1275-1282
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• 2012

Helicopter rotor systems are dynamically loaded structures with many composite components such as the main and the tail rotor blades. The fatigue properties of composite materials are extremely important to design durable and reliable helicopter rotor blades. The safe-life methodology has generally been used in the helicopter industry to substantiate dynamically loaded composite components. However, it cannot be used to evaluate the strength reducing effects of flaws and defects that may occur during manufacturing and operational usage. The damage tolerance methodology provides a proper means to overcome this shortcoming; however, it is difficult to economically apply it to every composite component. The flaw tolerant methodology is an equivalent option to the damage tolerance methodology for civil and military rotorcraft. In this study, the flaw tolerant safe-life evaluation is described and illustrated by means of successful application to substantiate the retirement time of composite rotor blades.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.5
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• pp.436-442
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• 2020

ESS(energy storage system) has recently become an important power source in various areas due to increased renewable energy resources. The more ESS is used, the less the effective capacity of the ESS. Therefore, it is important to manage the remaining useful lifetime(RUL). RUL can be checked regularly by inspectors, but it is common to be monitored and estimated by an automated monitoring system. The accurate state estimation is important to ESS operator for economical and efficient operation. RUL estimation model usually requires complex mathematical calculations consisting of cycle aging and calendar aging that are caused by the operation frequency and over time, respectively. A lightweight RUL estimation model is required to be embedded in low-performance processors that are installed on ESS. In this paper, a lightweight ESS RUL estimation model is proposed to operate on low-performance micro-processors. The simulation results show less than 1% errors compared to the original RUL model case. In addition, a performance analysis is conducted based on ATmega 328. The results show 76.8 to 78.3 % of computational time reduction.

• Korean Journal of Construction Engineering and Management
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• v.7 no.3 s.31
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• pp.112-121
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• 2006

The purpose of this study is to execute economical analysis for two types of office building HVAC system using LCC technique : single vs, separated HVAC(equal partition installation, unequal partition installation) system. The research method of this study includes the case analysis and questionnaire surveys. The results of this study are as follows: (1) LCCs of 3 types of HVAC system are estimated and the most economical one is investigated as single HVAC system, (2) In this case study, the single HVAC system was investigated as 34% lower in LCC during 15 years per $100m^2$ compared to equal partition installation, as 41% compared to unequal partition installation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.177-184
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• 2017

Understanding trends and drivers of technology diffusion is imperative to forecast new technology adoption and understand the process of technological innovation. Our research utilizes a quantitative trend analysis considering both technological and economic indicators for trends and drivers of technology diffusion for 32nm, 22nm, and 14nm logic semiconductor technology. In terms of technological performance, the technology diffusion curve showed an S-curve pattern during the stages of maturity and decline, and the diffusion curve showed evidence supporting the learning curve. The diffusion curve showed the life cycle duration of 2 years, and the rate of technological performance and obsolescence are observed quantitatively between generations. Architectural innovation is affected by technological drivers more significantly than economic drivers. This research has implications as empirical research on the trends and drivers of technology diffusion in the high-tech semiconductor industry, and is meaningful in forecasting new technology adoption or build technology strategy.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.233-241
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• 2017

Annual reports on the ease of doing business, published from the World Bank, measure the regulations of economies that enhance business activity and those that constrain it by the 10 areas of business life-cycle. It then calculates the scores and ranks in each of the areas and in aggregate. The aggregate scores are the summation of the scores in the areas. This means that all the areas have the same weight. As evaluation results can vary greatly by the areas used and their weights, it is possible that the areas emphasized by small and medium-sized enterprises(SMEs) of Korea are not appropriately reflected in the evaluation results. From the viewpoint of small and medium-sized Korean enterprises, this paper tries to compare the ease of doing business of economies via determining the weights of the 10 areas. Through an AHP-based survey on Korean professors of a business school and SME CEOs, the weights are determined and then applied to the calculation of the aggregate scores and the ranks of the economies. While the changes in the top and bottom ranks are relatively small, some cases of big changes are found in the middle ranks.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.107-111
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• 2017

The reliability on high cycle fatigue damage mechanism for new blades manufactured by reverse-engineering is demonstrated by success-run test. Turbine blades always experience various dynamic loads in turbine operation, as well as being in resonance condition and forced by fluid-induced vibrations mostly during run-up/down, which may accumulate high cycle damage to the blades. The accidents caused by blade failure especially incur not only a lot of troubles to the machinery but also huge financial losses. Therefore it is necessary to verify the reliability of blades in advance for the safe use. The success run test for the reliability demonstration is designed and performed for the new blades using the technique known as resonant high cycle fatigue testing.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.329-332
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• 2003

The Ministry of Construction and Transportation has estimated the reconsideration of economy in construction and the dullness of LCC forcast method which supports decision-marking in safety and maintenance of buildings. So, they have introduced LCC analysis method in steps of a feasibility study and design. Because of the introduction of LCC analysis process and method, it would be possible to make a logical decision from management maintenance, estimation, user point of view. In this study, it would bepossible to show a plan and alternative of design factors and structure in one building by using LCC analysis method and to compare and analyze the reduction of life circle cost bi the elapsed time.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.4
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• pp.279-288
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• 2001

This paper is to derive energy retrofit strategies through energy audit and analysis for a selected small-to-medium office building located in Seoul, Korea,. To activate ESCO business in Korea, our final goal is to develope a simple and adequate energy retrofit procedure through computer simulation. Calibration process was fairly successful eve without the aid of tough field measurement. In terms of annual energy consumption, the percent difference between the predicted and the monitored values were within a reasonable tolerance of $\pm10$%. Based on the calibrated baseline model and the systematic investigation of target building, retrofit measures were suggested with two categories such as architectural side and equipment side. Both selected parametric and interactive retrofit measure simulations resulted in various energy saving quantities and cost, thus the priority among the measures were made. If we were to select the more realistic and reasonable retrofit measure in future, economic estimate were should be practiced with the life cycle cost analysis.