• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.606-609
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• 2009

Development of renewable energy is very important because of environmental problems caused by greenhouse effect. This is due to the use of fossil fuels which has serious consequences. Therefore, development of small hydropower can be a good countermeasure for the problems. The small hydropower is clean energy because the small hydropower generates few $CO_2$. Moreover, as the energy density by the small hydropower is high, it is economical for a society which wants to introduce the system. The purpose of this study is to improve the turbine performance. This study is about tubular-type hydro turbine among renewable energy that is based using the different water pressure level in pipe lines. The analysis was performed using the commercial CFD code ANSYS-CFX.

• 태양에너지
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• 제18권3호
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• pp.153-160
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• 1998

The methodology and feasibility analysis model for small hydropower plant has been studied and developed. It consists of two main part, the performance prediction model to estimate the performance characteristics and economics anaysis model to evaluate economical characteristics for surveyed sites. The performance characteristics and feasibility assessment for surveyed sites were analyzed, using developed models. Also, primary design specifications such as design flowrate, capacity, load factor were estimated and discussed for surveyed sites in Dan-yang and feasibility was suggested through analyzing the investment, unit cost and payback period.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.105-108
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• 2000

The economical detection of dual-tone multifrequency(DTMF) signals is an important factor when developing cost-effective telecommunication equipment. Each channel has independently a DTMF receiver, and I t informs the detected signal to processors. This paper analyze the power spectra and evaluate the performance of DTMF receiver by using tile quick Fourier transform(QFT) algorithm. As experimental results, it show the improved performance to the DTMF receivers and reduce memory waste and process the real-time.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.82-87
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• 2007

In the present study, the simulation on the annual performance evaluation of a renewable energy systems with fuel cell driven compound source hybrid heat pump systems is applied to the heating and cooling of large community building. The large community building has the economical advantage to apply heat pump cooling and heating systems the long period operation. If air and ground source hybrid heat pump systems are combined, COP of the system can be increased largely. Fuel cell driven compound source hybrid heat pump system can reduced the fuel cost as well as thermal storage tank sharply.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.105-106
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• 2017

Previous studies have confirmed the performance of pH reduction agents using liquid sodium phosphate based ammonium chloride as a pH reduction agent. In this study, the pH reduction performance considering economical and applicability as a practical stage and the property change analysis for the identification of the reaction mechanism of the pH reduction agent were carried out. As a result, the pH reduction performance at a low rate of the pH reducing agent was confirmed. The specific gravity of CaO decreased significantly after XRF analysis. It is also believed that this reduces the amount of Ca(OH)₂ produced and contributes to pH reduction.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.134-136
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• 2013

In general, the seismic retrofit is almost essential to extend and remodel aged buildings. Because domestic seismic design code has been enhanced, seismic performance should be secure for aged building remodeling. Seismic response reduction device (damper) is lately appling to ensure seismic performance. This device is economical efficiency method that can reduce the load to foundation and the range of structural reinforcements, shorten of construction period. New shaped steel damper was applied for extension and remodeling construction for Boramae Deakyo building. As a result, the economy and shortening of construction period was achieved.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제11권3호
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• pp.43-52
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• 2007

A hard disk, which can be classified as an external storage is usually capacious and economical. In spite of the attractive characteristics and efforts on the performance improvement, however, the operation of the hard disk is apparently slower than a processor and the advancement has also been slowly conducted since it is based on mechanical process. On the other hand, the advancement of the processor has been drastically performed as semiconductor technology does. So, disk I/O sub-system becomes bottleneck of computer systems' performance. For this reason, the research on disk I/O sub-system is in progress to improve computer systems' performance. In this paper, we proposed multi-level LRU scheme and then apply it to the computer systems with buffer cache and disk cache. By applying the proposed scheme to computer systems, the average access time to disk blocks can be decreased. The efficiency of the proposed algorithm was verified by simulation results.

• 한국의류학회지
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• 제28권7호
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• pp.1007-1018
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• 2004

Luxury fashion brand business is one of the most successful global businesses in these days. The luxury fashion brands with strong brand power permeates through various regions of the world with high added value and buying power. This study was conducted to determine the dimensions of the luxury fashion brand equity so that the fashion marketers can develop strategies to increase their brand power. ID find out the dimensions of the luxury fashion brand equity, qualitative as well as quantitative research methods were employed. Qualitative research was conducted by interviewing 12 consumers who were loyal to the luxury fashion brands. A total of ten dimensions(uniqueness, sophistication, display, economical and utility value, overall pleasure, satisfaction, reputation, trust respect, social acceptance) were identified as a result of the literature review and the qualitative analysis, and a questionnaire was developed based on them. The questionnaire was administered to 250 subjects and the responses were analyzed by factor analysis to confirm the dimensions empirically. As a result of factor analysis, 7 dimensions of fashion luxury brand equity are ＇chic and pleasure＇, ＇trust＇, ＇distinction＇, ＇reputation＇, ＇economical and utility value＇, ＇social acceptance＇, and ＇status＇. First, ＇reputation＇, ＇economical and utility value＇ and ＇social acceptance＇ are similar to the result of the literature review and the qualitative analysis. Next, ＇Chic and pleasure＇ included ＇overall pleasure＇,＇display＇and＇sophistication＇that were identified previously. We knew that People would expect emotional responses such as display through luxury fashion brand. ＇Trust＇ included ＇trust＇ and ＇satisfaction＇ that were identifed previously. ＇Distinction＇ included ＇uniqueness＇ and ＇respect＇ that were identifed previously. Finally, ＇status＇ included ＇sophistication＇ and ＇reputation＇ It seemed that the concept of ＇sophistication＇ was near symbolic rather than descriptive.

• 한국소음진동공학회논문집
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• 제20권11호
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• pp.995-1000
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• 2010

With the development of the auto industry, the automobile manufacturers demand to shorten development period and reduce the cost. Compared with the traditional method, applying the virtual prototype is more economical. This paper presents a method for parameters sensitivity analysis and optimizing the performance of vehicle noise and vibration. The existing design processes were repeatedly analyzed with a focus on vehicle performance to decide the design parameters of dimension, thickness, mounting type of body and chassis systems in the vehicle development period. This paper describes the prediction technique of vehicle performance using L18 orthogonal array layout, quality deviation analysis and parameter sensitivity analysis for robust design. This paper analyzed the performance correlation equation through the frequency and sensitivity database according to a design factor change. The new concept is that the performance prediction is possible without repeated activities of test and analysis. This paper described the parameter analysis applications such as bush dynamic stiffness and bush void direction of rear suspension. Design engineer could efficiently decide the design variable using parameter analysis database in early design stage. These improvements can reduce man hour and test development period as well as to achieve stable NVH performance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.597-602
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• 1998

The composite systems, consisting of R/C Columns-Steel Beams, are reasonable structures because of their constructional and economical advantages, workability and so on. But, it is difficult to apply the composite systems to actual design due to material dissimilarity and complicate stress flow in the connection. This study aims to propose the hybrid beam-column connection system with structural tee and through experimental research make clear the shear and moment resistance capacity and stress transfer mechanism.