• Proceedings of the KIEE Conference
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• summer
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• pp.1208-1210
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• 2004

The Cold-Cathode Fluorescent Lamps (CCFL) are widely used to illuminate the liquid crystal displays(LCD) used in many battery powered instrument. This paper presents analysis of fly-back converter for universal-line applications($90\sim265Vac$) and half-bridge type resonant inverter for CCFL drive for stable characteristic and life improvement of fluorescent lamp operation frequency is higher than resonant frequency for safe operation. The validity of this study was confirmed from the simulation and experiential result.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.376-381
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• 2011

In Korea Water Resources Corporation (K-Water) has seen four problems rising in four aspects of property management of approximately 1,300 buildings scattered through put to country. To solve these, ground data for repair and replacement works to be conducted for prevention will be prepared and building maintenance system (hereinafter referred to as PBMS) intended to record related repair and replacement work histories and calculate LCC of the related these items will be developed. PBMS, a web-based system, will be developed for users' convenience and data monitoring in real time. To sum up, PBMS are expected to maximize efficiency in four aspects including the establishment of repair and replacement work plans for prevention, history management, DB for predicting future work to be occurred and enable the determination of priorities by being developing into facility condition assessment systems through the results of analysis of repair and replacement histories and LCC.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1132-1140
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• 2007

As it recently appears that Life Cycle Cost Analysis may be considered as new methodology for economic valuation of infrastructure many researches have been made to assess LCC(Life Cycle Cost) of each facility based on a reasonable methods. In general, LCC is composed of construction cost and expected maintenance repair cost. And especially, maintenance repair cost must be estimated to enhance the reliability through systematic and reasonable methods. However in Korea, because high speed railway steel bridges are recently constructed no direct statistical data are available for the account of the maintenance cost and then their maintenance characteristics are not linear yet. Therefore, the approach proposed in the paper utilizes a theoretical determination and degradation of the corrosion and fatigue of the bridges based on Rahgozar et al.(2006)'s model on fatigue notch factor considering into the corrosion to incorporate the corrosion effect into the fatigue strength reduction model. And then, the corresponding probability of failure is calculated in terms of the reliability index using S-N curve to formulate the fatigue limit state. Therefore, this paper proposes the minimum Life Cycle Cost through optimum maintenance plan analysis of high-speed railway steel bridges under construction. Finally, this paper reviews the proposed model in oder to confirm the applicability and feasibility by appling it to high speed railway steel bridges under construction

• Proceedings of the IEEK Conference
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• 2000.06c
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• pp.51-54
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• 2000

In this paper, an compiler system is ported and modified for register allocation experiments. This compiler system will enable various global register allocation. Lcc is introduced and Chaitin's graph coloring algorithm is executed with cmcc on DEC ALPHA 255/300. Several functions of SPEC921NT is used as inputs of the compiler system.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.710-714
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• 2011

In present work, $La_{0.8}Ca_{0.2}CrO_{3}$(LCC), $La_{0.8}Sr_{0.2}CrO_{3}$(LSC) and $La_{0.8}Ca_{0.2}CrO_{0.9}Co_{0.1}O_{3}$(LCCC) ceramic interconnect layer for SOFC were prepared by using thermal plasma spray coating process. The LCC, LSC and LCCC powders were characterized by x-ray diffraction(XRD), scanning electron microscopy(SEM), particle counter and BET analysis. In addition, basic and essential properties such as the surface morphology, cross section, gas leak rate, and electrical conductivity of LCC, LSC, and LCCC layers coated by thermal plasma spray coating process were analyzed and discussed. Based on these experimental results, it can be concluded that the LCCC layer coated by thermal plasma spray coating process can be suitable as a ceramic interconnect of SOFC.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.1
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• pp.44-49
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• 2015

Ceiling cooling and heating system that consider load arrangement and space in the ceiling needs to be developed. Therefore, experimental and economic changes were done to verify the performance of compact type VAV. The test results were as follow. 1) Noise test result, measuring approximately 50.4 dB~56.6 dB (before ceiling in landfill), had a better ceiling deadline than the current measure, about a 10 dB noise reduction, so that the office baseline (40~50 dB) noise was judged to be less than test. 2) For the static pressure test result, taking out an outside hydrostatic 25 mmAq, 24.8 mmAq was measured, respectively, at the point. 3) For the life-cycle cost analysis result, the initial investment cost, maintenance replacement costs, and maintenance costs increased 0.2%, but the energy savings ratio was 19.5% while the whole life cycle savings of 40 years LCC was reduced 11.9%.

• Earthquakes and Structures
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• v.9 no.1
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• pp.73-91
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• 2015

The effectiveness of tuned mass dampers (TMDs) in reducing the seismic response of civil structures is still a debated issue. The few studies regarding TMDs on inelastic structures indicate that they would perform well under moderate earthquake loading, when the structure remains linear or weakly nonlinear, while tending to fail under severe ground shaking, when the structure experiences strong nonlinearities. TMD seismic efficiency should be therefore rationally assessed by considering to which extent moderate and severe earthquakes respectively contribute to the expected cost of damages and losses over the lifespan of the structure. In this paper, a method for evaluating, in a life-cycle cost (LCC) perspective, the seismic effectiveness of TMDs on inelastic building structures is presented and exemplified on the SAC LA 9-storey steel moment-resisting frame benchmark building. Results show that the LCC concept may provide an appropriate alternative to traditional performance criteria for the evaluation of the effectiveness of TMDs and that TMD installation on typical existing middle-rise buildings in high seismic hazard regions may significantly reduce building lifetime cost despite the poor control performance observed under the most severe seismic events.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.7
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• pp.299-304
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• 2016

In recent years, heat source systems which have a principal effect on the performance of buildings are difficult to design optimally as a great number of design factors and constraints in large and complicated buildings need to be considered. On the other hand, it is necessary to design an optimum system combination and operation planning for energy efficiency considering Life Cycle Cost (LCC). This study suggests a multi-level and multi-objective optimization method to minimize both LCC and investment cost using a genetic algorithm targeting an office building which requires a large cooling load. The optimum method uses a two stage process to derive the system combination and the operation schedule by utilizing the input data of cooling and heating load profile and system performance characteristics calculated by dynamic energy simulation. The results were assessed by Pareto analysis and a number of Pareto optimal solutions were determined. Moreover, it was confirmed that the derived operation schedule was useful for operating the heat source systems efficiently against the building energy requirements. Consequently, the proposed optimization method is determined by a valid way if the design process is difficult to optimize.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.64-69
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• 2009

Because of their low operating and maintaining costs, ground-source heat pump(GSHP) systems are an increasingly popular choice for providing heating, cooling and water heating to public and commercial buildings. Despite these advantages and the growing awareness, GSHP systems to residential sectors have not been adopted in Korea until recently. A feasibility study of a residential GSHP system was therefore conducted using the traditional life cycle cost(LCC) analysis within the current electricity price framework and potential scenarios of that framework. As a result, when the current residential electricity costs for running the GSHP system are applied, the GSHP system has weak competitiveness to conventional HVAC systems considered. However, when the operating costs are calculated in the modified price frameworks of electricity, the residential GSHP system has the lower LCC than the existing cooling and heating equipments. The calculation results also show that the residential GSHP system has lower annual prime energy consumption and total greenhouse gas emissions than the alternative HVAC systems considered in this work.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.8 no.3
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• pp.12-18
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• 2012

The purpose of this study is to make an economic analysis(Life cycle cost) of selecting optimal air conditioning system for a research building which is 8 stories with a total floor area of $32,010m^2$. Energy consumptions of three proposed air-conditioning systems(Alt-1,2,3) that reflect the government green-growth policy are calculated and compared. The results show that life cycle cost of Alt-3(Ventilation DX AHU+EHP) is less than Alt-1(EHP+ventilation DX AHU) by 5.1%, and Alt-2(Absorption chiller/heater+EHP) by 34.3%. Annual energy consumption of Alt-3 is less than Alt-1 by 9.9%, and Alt-2 by 37.4%. Annual $CO_2$ emission of Alt-3 is less than Alt-1 by 9.9%, and Alt-2 by 0.2%.