• 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.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.167-172
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• 2011

Generally, the analysis of railroad wear data is most effective method for the efficient railway maintenance. The wear of railway track affects loss of rough ride, noise or vibration of train and traveling safety. Moreover as the track is worn away, this promotes destruction of structural mechanism of rail track which can bring about increasing of rail track maintenance cost drastically. For this reason, it is very important and interested research subject to design railway track structure and to analyse train movement mechanism based on systematic analysis of the reasons causing rail wear possible in real field. In this research, for the efficient maintenance, Life Cycle Performance of rail track and maintenance characteristics are computed considering some track components such as track type, contracting type, sleeper type and roadbed type. Time - Wear probabilistic distribution relationship as well as multiple regression analysis based on time, curvature and wear data are computed to predict the service life remainder of railway track and to be adapted to safety assessment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.193-201
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• 2014

This study attempts to utilize the economic efficiency analysis results focused on the break-even point as an indicator for the decision making of commanders and staff. We suggested a method of determining economic life by utilizing logistics information system and commercial program Minitab with a focus on the equipment's operational environment and performance data, whereas previously the equipment's retirement period was simply determined by the current equipment prices and sustainable period.

• Structural Engineering and Mechanics
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• v.77 no.2
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• pp.197-215
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• 2021

Under a severe environment of multiple hazards such as earthquakes and winds, the life-cycle performance of engineering structures may inevitably be deteriorated due to the fatigue effect caused by long-term exposure to wind loads, which would further increase the structural vulnerability to earthquakes. This paper presents a framework for evaluating the lifetime structural seismic performance under the effect of wind-induced fatigue considering different sources of uncertainties. The seismic behavior of a high-rise steel-concrete composite frame with buckling-restrained braces (FBRB) during its service life is systematically investigated using the proposed approach. Recorded field data for the wind hazard of Fuzhou, Fujian Province of China from Jan. 1, 1980 to Mar. 31, 2019 is collected, based on which the distribution of wind velocity is constructed by the Gumbel model after comparisons. The OpenSees platform is employed to establish the numerical model of the FBRB and conduct subsequent numerical computations. Allowed for the uncertainties caused by the wind generation and structural modeling, the final annual fatigue damage takes the average of 50 groups of simulations. The lifetime structural performance assessments, including static pushover analyses, nonlinear dynamic time history analyses and fragility analyses, are conducted on the time-dependent finite element (FE) models which are modified in lines with the material deterioration models. The results indicate that the structural performance tends to degrade over time under the effect of fatigue, while the influencing degree of fatigue varies with the duration time of fatigue process and seismic intensity. The impact of wind-induced fatigue on structural responses and fragilities are explicitly quantified and discussed in details.

• Korean Journal of Construction Engineering and Management
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• v.6 no.6 s.28
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• pp.133-141
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• 2005

In the resent years, the importance of VE (value engineering) and LCC (life cycle cost) analysis for apartment building construction projects has been fully recognized. Accordingly theoretical models, guidelines, and supporting software systems were developed for the value engineering and life cycle cost analysis for construction management including large building systems. However, the level of consensus on VE and LCC analysis results is still low due to the lack of reliable data on maintenance. This paper presents time dependent LCC model based value analysis method for rational investment decision making and design alternative selection for construction of apartment building. The proposed method incorporates a time dependent LCC model and a performance evaluation technique by fuzzy logic theory to properly handle the uncertainties associated with statistics data and to analyze the value of alternatives more rationally. The presented time dependent VE and LCC analysis procedure were applied to a real world project, and this case study is discussed in the paper. The model and the procedure presented in this study can greatly contribute to design value engineering alternative selection, the estimation of the life cycle cost, and the allocation of budget for apartment building construction projects.

• Smart Structures and Systems
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• v.16 no.4
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• pp.743-758
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• 2015

This paper presents an advanced life cycle cost (LCC) analysis of a ground source heat pump (GSHP) system and suggests a smart operation mode with a thermal performance test (TPT) and an energy pile system constructed on the site of the Incheon International Airport (IIA). First, an economic analysis of the GSHP system was conducted for the second passenger terminal of the IIA considering actual influencing factors such as government support and the residual value of the equipment. The analysis results showed that the economic efficiency of the GSHP system could be increased owing to several influential factors. Second, a multiple regression analysis was conducted using different independent variables in order to analyze the influence indices with regard to the LCC results. Every independent index, in this case the initial construction cost, lifespan of the equipment, discount rate and the amount of price inflation can affect the LCC results. Third, a GSHP system using an energy pile was installed on the site of the construction laboratory institute of the IIA. TPTs of W-shape and spiral-coil-type GHEs were conducted in continuous and intermittent operation modes, respectively, prior to system operation of the energy pile. A cooling GSHP system in the energy pile was operated in both the continuous and intermittent modes, and the LCC was calculated. Furthermore, the smart operation mode and LCC were analyzed considering the application of a thermal storage tank.

• Journal of Intelligence and Information Systems
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• v.15 no.4
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• pp.37-51
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• 2009

One of the critical issues in the management of manufacturing companies is the efficient process of planning and operating service resources such as human, parts, and facilities, and it begins with the accurate service demand forecasting. In this research, service and sales data from the LCD monitor manufacturer is considered for an empirical study on Product Life Cycle (PLC) based service demand forecasting. The proposed PLC forecasting approach consists of four steps : understanding the basic statistics of data, clustering models using a self-organizing map, developing respective forecasting models for each segment, comparing the accuracy performance. Empirical experiments show that the PLC approach outperformed the traditional approaches in terms of root mean square error and mean absolute percentage error.

• Journal of Environmental Science International
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• v.22 no.3
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• pp.281-289
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• 2013

For the purpose of evaluating the eco-efficiency(EE) on surplus heat generated from industrial process, techniques of life cycle assessment are adopted in this study. Because it can be indicated both environmental impacts and economic benefits, EE is well known as a useful tool for symbiosis network on the sustainable development of new projects and businesses. To evaluate environmental impacts, the categories were divided into two areas of resource depletion and global warming potential. It can be seen that environmental impact increased a little but much higher economic benefit on the company, environmental performance and economic value were improved on the apartment by the district heating, respectively. In result, eco-industrial park(EIP) project on surplus heat should be found sustainable new business because the EE was in the area of fully positively eco-efficiency and, moreover resource depletion was taken place than the reduction of greenhouse gas.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.4
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• pp.135-147
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• 2018

There has been a recent increase in the interest towards founding companies and in line with the South Korean Government's policy on start-up support, discussions are rife about the effect of entrepreneurship on the management and performances of these companies. To enhance the competitiveness of SMEs, it is expedient to acquire and deploy consistent entrepreneurship, differentiate corporate resources, ensure the appropriate utilization of resources and the integration of such factors in response to the changing environment. This research examines relationships among entrepreneurship, three components of corporate capabilities, dynamic capability and technical performance based on resource-based view and the dynamic capability theory. The authors also investigate the moderating role of corporate life cycle. To test the hypothesis, we conducted a survey on 352 technologies -innovative SMEs located in South Korea via professional research institutes. The findings confirm the hypothesis that SMEs' entrepreneurship has a positive effect on three kinds of corporate capabilities (e.g., marketing, R&D, operations capability), and it had a positive effect on dynamic capability, whiles dynamic capability also had an influence on technical performances. The findings also confirmed the hypothesis that corporate life cycle moderates the relationship between dynamic capability and technical performances respectively. The research implications for both practitioners and academicians are discussed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.7
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• pp.491-499
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• 2007

An architectural means of optimal daylight distribution is by using so-called light shelf systems, horizontal shading and redirecting devices. The overall performance of the daylighting system can be improved by the incorporation with electric lighting control devices. This paper aims to exemplify the benefit of daylighting in term of economic consideration. In such a case a reasonable technique to compare system costs is by life-cycle costing. Stated simply, a life-cycle cost represents the total cost of a system over its entire life cycle, that is, the sum of first cost and all future costs. Four different electric lighting system designs are proposed and a lighting control system that is continuously operating according to the level of daylight in the space has been adapted. The result shows clearly that although denser layout of lighting fixtures might be more effective to interface to the level of daylight ceaselessly changeable, its economic benefit may not meet the expected criterion the reason of increased initial investment and maintenance cost for the fixtures and control devices.