• 한국입자에어로졸학회지
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• 제18권3호
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• pp.61-68
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• 2022

In this study, a fluidized bed particle generator was developed to generate an aerosol without supply of compressed air and to increase portability. It was assumed that the mixing ratio of the test particles and beads, the input amount, and the air flow rate supplied to the generator would have effect on the aerosol generation characteristics. The product of these three parameters was set as a characteristic parameter and particle generation characteristics according to the change of the characteristic parameter were observed. As a result, it was confirmed that the input amount of test particles and beads was not suitable as a characteristic parameter and a characteristic parameter expressed as a product of the mass mixing ratio and the air flowrate was newly defined. When the new characteristic parameter is applied, it can be confirmed that the total amount of particles generated from the particle generator is a function of the characteristic parameter. As a result of measuring the amount of particle generation by adjusting the characteristic parameter, it was confirmed that the performance required for the test particle generator for the field inspection equipment of PM-2.5 sensors could be satisfied.

• 정보처리학회논문지D
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• 제16D권1호
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• pp.73-82
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• 2009

오픈소스 소프트웨어는 응용 소프트웨어 개발의 60% 이상을 차지하고 있으나 이를 활용하기 위한 객관적인 품질 모델이나 지표에 대한 연구가 초보적인 수준에 머물고 있으며, 이를 평가하기 위한 정량적인 평가 기법에 대한 연구도 거의 이루어지고 있지 않다. 본 연구는 응용 소프트웨어 개발 및 유지보수에 활용할 수 있는 품질평가 모델을 제시하고, 제시된 품질평가 모델에서 활용할 수 있는 정량적 품질 평가 기법을 제시한다. 제안한 오픈소스 소프트웨어 품질 모델은 문헌 자료를 기반으로 품질 특성을 도출하고, 이를 ISO 9126의 품질 특성과 비교 검토하여 6개의 주특성과 12개의 부특성과 이를 정략적으로 측정할 수 있는 12개의 평가 메트릭으로 구성된 '논리적 오픈소스 소프트웨어 품질 모델'을 제안하였다. 제안한 품질 평가 모델의 효율성을 검증하기 위하여 오픈소스 소프트웨어 커뮤니티에 있는 상위 Rank 5개의 프로젝트 관리 시스템(PMS) 관련 소프트웨어를 대상으로 제안한 품질평가을 적용하여 그 가능성을 입증하였다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1990년도 춘계공동학술대회논문집; 한국과학기술원; 28 Apr. 1990
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• pp.335-343
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• 1990

The traditional economic evaluation methods do not seem to consider derivative efforts-productivity improvement, quality improvement.-which may be occured by AMS introduction. Current evaluation methods are based on mass production with known characteristic and stable technology. Recently, expert suggest that these assumption-stable production and mass production-are realized to be a limited in substantial economic evaluation analysis. Therefore, the problem of traditional evaluation methods suggested in this thesis and decision in the case studies are derived using two complementary economic analysis methods-AHP method, modified economic evaluation model- and traditional evaluation method. After three methods are compared and evaluated in the view of practical economic evaluation, AHP method is intended to be introduced as a new economic evaluation method.

• 한국정보과학회논문지:정보통신
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• 제36권1호
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• pp.50-56
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• 2009

본 논문에서는 P2P 네트워크 환경에서 유사한 특성을 가진 다른 노드(node)를 찾아 추천자(recommender) 그룹을 형성하고 유지하는 새로운 알고리즘을 제안한다. 두 노드의 유사한 특성을 비교하기 위해 본 논문에서는 두 노드의 특성값(characteristic value. 이하 CV)을 이용한 적합도 검사(fitness evaluation)를 사용하여 유사도(similarity)를 확인한다. 유사도의 크기가 작을수록 두 노드는 매우 유사한 특성을 가지게 된다. 또한, 본 논문에서 제안하는 GORGFM(Globally Optimal Recommender Group Formation and Maintenance) 알고리즘은 최단 기간 내에 최적의 추천자 그룹을 형성하고 사용자의 선호도 변화에 대응할 수 있는 알고리즘이다. GORGFM 알고리즘을 평가하기 위해 본 논문에서는 매칭율(matching rate)과 얼마나 빠르고 정확하게 추천자 그룹을 형성하는가에 대해 시뮬레이션 한다. GORGFM 알고리즘은 네트워크에서뿐만 아니라 인터넷상에서 컨텐츠(contents) 검색 등과 같이 적합도 함수(fitness function)를 이용할 수 있는 모든 시스템에 적용할 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.374-376
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• 2005

Due to the pressure of opening electric power market, the transmission system reliability evaluation is being more important. This paper presents a reliability evaluation method for a specific area using the elastic power system frequency decline characteristic. The practicality and effectiveness of this methodology is illustrated by a case study.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.330-332
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• 1992

This paper tries to evaluate the control performance of systeme in cases of parameter perturbations. Six cases of the root distribution and location changes of each characteristic roots by the parameter perturbation are considered as evaluation factors. A qualitative evaluation is performed through several simulations. These results will be used as a basic data for the complete analysis of the control performance.

• Food Science and Biotechnology
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• 제14권4호
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• pp.450-455
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• 2005

This study was conducted to determine firstly the composition of the essential oil from fresh changpo (Acorus calamus var. angustatus Bess) roots quantitatively and qualitatively by use of two internal standards, and secondly volatile compounds which are primarily responsible for the aroma of changpo roots. Simultaneous steam distillation and extraction method was used for essential oil extraction, and aroma extract dilution analysis (AEDA) and sniffing test by gas chromatography/olfactometry (GC/O) were used to detect the characteristic impact odorants. According to the instrumental analysis of changpo root essential oil, cis, trans-famesol (47.56 mg/kg of fresh wt), octanoic acid (23.73 mg/kg of fresh wt), trans-2-dodecenal (20.28 mg/kg of fresh wt) and trans, trans-farnesol (13.81 mg/kg of fresh wt) were the most abundant compounds. Geranyl acetate, trans-nerolidol and trans, trans-farnesyl acetate were evaluated as the characteristic impact odorants of changpo roots from results of AEDA and sniffing test. Especially, geranyl acetate was considered as the most similar odor component to changpo roots by organoleptic evaluation with GC/O.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.437-442
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• 2005

This paper deals with the measurement and analysis of radio characteristic of 424 MHz for using the automation of transmission and supply of electric power, ana automatic meter reading(AMR). Normally radio propagation characteristic is the base of system design, performance evaluation and choice of position of the base station in wireless communication. It is the most accurate way to design a base station through practical measurements, but it costs much time, money and engineers. So, we developed 424 MHz short range wave propagation model for AMR service.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1394-1399
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• 2001

The purpose of this paper is that investigates the dynamic behavior characteristic of W.T.S(Wind Turbine System) and carries out the evaluation analysis during operating W.T.S. To investigate the dynamic behavior characteristic of W.T.S. the experiments to measure vibration of the blade from the attached accelerometer on the flap and edge section of the blade that is one of the most important elements of dynamic characteristic of W.T.S are performed. Natural frequency and mode shape are calculated with commercial program (STAR MODAL) using the measured vibration acceleration that receives the signal with F.F.T Analyzer from the accelerometer. For validation of these experiments. the finite element analysis is performed with commercial F.E.M Program (ANSYS) on the basis of the natural frequency and mode shape. The results indicate that experimental values have good agreements with the finite element analysis.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1761-1765
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• 2008

In the braking of a railroad car, mechanical brake systems using wheel tread and brake disk are applied as well as electrical brake systems by regenerator and rheostat. It is very important to consider the frictional characteristic because kinetic energy of the vehicle is dissipated as converted thermal energy through friction between disk and brake pad during disk braking. A friction coefficient and wear characteristic are decided from the interrelationship of disk and friction material in the disk brake system. Lab-scale dynamometer test on developed brake disk materials for increasing heat resistance was performed in this study. Each candidate material was tested at various braking speeds and pressures and we obtained the friction coefficient and wear characteristic. And we executed comparative evaluation of the result from the test.