• 대한토목학회논문집
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• 제31권5B호
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• pp.405-414
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• 2011

본 연구에서는 유역에서 관측되는 강우량과 유출량의 시계열 자료를 바탕으로 최근 시계열 예측 및 시스템 제어 분야에서 성공적으로 적용되고 있는 적응형 네트워크 기반 퍼지추론 시스템(ANFIS)을 갑천 유역에 적용하여 시유출량을 모델링하였다. 입력구조, 소속함수 종류와 개수 등을 다양하게 변화시켜 ANFIS 모형을 학습하고, 평균제곱근오차(RMSE), 평균첨두유량오차(PE) 및 평균첨두시간오차(TE)를 이용하여 ANFIS의 유출해석에 대한 적용성을 평가하였다. 현재시간의 시유출량 Q(t)에 대한 ANFIS의 적용성은 우수한 것으로 평가되었으며, ANFIS 모형은 관측유출량을 적절히 모의하였다. 입력구조가 다른 입력모형을 구성하여 최대 8시간까지 ANFIS의 유출예측 적용성을 평가하였다. 예측시간 증가에 따라서 ANFIS의 유출예측 정확도는 감소하여 예측시간 4시간 이상의 시유출량에 대한 ANFIS의 유출예측 적용성은 제한적이었다. ANFIS는 입력과 출력 자료들만 이용하므로 물리기반 모형에 비교하여 모형구축이 비교적 손쉽기 때문에 홍수 유출모델링에 ANFIS을 유용하게 적용할 수 있을 것으로 판단된다.

• 한국태양에너지학회 논문집
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• 제32권2호
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• pp.95-104
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• 2012

This study purposed to predict wind energy for small size wind power generators at 50m above the ground in each area using mean wind speed data for 10 minutes collected from 2001 to 2011 by meteorological data in large cities having over 60% of 15 story (50m) or higher apartments including Seoul, Daejeon, Gwangju and Daegu representing the inland region, and Busan, Incheon and Ulsan representing the coastal region. In the results of analysis, we confirmed close agree ment between observatory weather data and probability density distribution obtained using Weibull's parameters, and this suggests that Weibull's parameter is applicable to the estimation of wind energy. Hourly output energy using the mean wind speed for 10 minutes and output energy obtained from Weibull's parameter showed an error less than 5%, and thus it was found that wind energy can be evaluated using Weibull's modulus.

• 대기
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• 제25권2호
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• pp.221-233
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• 2015

Pollen is closely related to health issues such as allergenic rhinitis and asthma as well as intensifying atopic syndrome. Information on current and future spatio-temporal distribution of allergenic pollen is needed to address such issues. In this study, the Community Multiscale Air Quality Modeling (CMAQ) was utilized as a base modeling system to forecast pollen dispersal from oak trees. Pollen emission is one of the most important parts in the dispersal modeling system. Areal emission factor was determined from gridded areal fraction of oak trees, which was produced by the analysis of the tree type maps (1:5000) obtained from the Korea Forest Service. Daily total pollen production was estimated by a robust multiple regression model of weather conditions and pollen concentration. Hourly emission factor was determined from wind speed and friction velocity. Hourly pollen emission was then calculated by multiplying areal emission factor, daily total pollen production, and hourly emission factor. Forecast data from the KMA UM LDAPS (Korea Meteorological Administration Unified Model Local Data Assimilation and Prediction System) was utilized as input. For the verification of the model, daily observed pollen concentration from 12 sites in Korea during the pollen season of 2014. Although the model showed a tendency of over-estimation in terms of the seasonal and daily mean concentrations, overall concentration was similar to the observation. Comparison at the hourly output showed distinctive delay of the peak hours by the model at the 'Pocheon' site. It was speculated that the constant release of hourly number of pollen in the modeling framework caused the delay.

• 한국태양에너지학회 논문집
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• 제28권3호
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• pp.60-66
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• 2008

This study is to investigate an optimal size and position of PV system for apartment complex through the electrical load matching analysis. The 4 types of arrangements of apartment buildings are considered as follows; ㅡtype, alternative ㅡtype, ㄱtype and ㅁtype. We assume that the studied site is composed of 9 buildings. Firstly, solar access evaluation of roof and facade in apartment buildings was performed with the hourly simulations of total received insolation on each surface considering the shading effect of buildings. Electrical load profile of typical Korean apartments were investigated for the load matching analysis. To calculate an annual total PV output, we used MERIT program which is a hourly based load matching tool developed by ESRD. TRY weather data of Daejeon are applied for this analysis. Result shows that approximately 11% of total electric load of the site can be supplied by the PV system in the case of full installation of PV system at the whole south-face roof area of 9 buildings in this stuided apartment complex. Depending on a various installation option of roof and facade area, the possible ratio of PV supply in total electrical load varies from 9% to 42%. Among the 4 arrangement types, the ㅡtype revealed the best option for the maximum output of PV system.

• 한국태양에너지학회 논문집
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• 제29권6호
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• pp.110-118
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• 2009

This research is an experimental study on BIPV Power performance of See-through a-si and Light-through applying external curtain wall. In case of See-through a-si Photovoltaic, appropriateness of facade applying standard($950\;{\times}\;980mm$) large($950\;{\times}\;1960mm$)area photovoltaic was examined. Transparent performance was also investigated through Power simulation according to angles and seasons of See-through a-si and Light-through Photovoltaic so that Power output was surveyed with using designed and manufactured Mock-up. When comparing See-through a-si to Light-through Photovoltaic for simulation Power output on angles based on full south aspect, which the result was that See-through a-si Power output according to Light-through Power output was the highest of 65.5% when applying a 90 degree angle. Monthly accumulated average Power output during winter seasons (December, January and February) applying a vertical plane on full south aspect was analyzed, which results in 66.37W/h of See-through a-si and 139.1 W/h of Light-through. See-through a-si Power output showed 47.7% in comparison with Light-through transparent. Also monthly, hourly average Power efficiency according to solar radiation during winter seasons (December, January and February) was that 4.7% of See-Through a-si and 9.8% of Light-through.

• 전기학회논문지
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• 제63권9호
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• pp.1199-1205
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• 2014

A power system configuration has been increasingly advanced with a number of generating units. In particular, renewable energy resources are widely introduced due to the environmental issues. When applying the renewable energy sources with the ESS (Energy Storage System), the ESS is the role of a potential generating resource in the power system while mitigating the output volatility of renewable energy resources. Thus, for applications of the ESS, the surrounding environment of it should be considered, which means that capacity and energy of the ESS can be affected. Moreover, operation strategy of the ESS should be proposed according to the installation purpose as well as the surrounding environment. In the paper, operation strategy of the ESS is proposed considering load demand and the output of renewable energy resources on a hourly basis. Then, the cost of electrical energy is minimized based on the economic model that consists of capital cost, operation cost, fuel cost, and grid cost for a year. It is sure that peak-shaving effects can be achieved while satisfying the minimum cost of electrical energy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.365-368
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• 2006

The objective of this research is to investigate usage of 3KW photovoltaic-wind power hybrid generation system composed of 500W solar power generator and 400W wind power generator in a parallel circuit. In addition, solar radiation meter and wind monitor have been installed into each generation system to obtain the practical operating data that monitored in monthly, daily and hourly. These data that are independent to weather change and location would provide adequate generation output on average and cope with emergency situation in generation system In conclusion, based on this study, it could be considered for 3KW combined generation system to be gradually propagated to houses and small-size public facilities.

• Korean Journal of Hydrosciences
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• 제4권
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• pp.1-9
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• 1993

It is a major objective for the management and operation of water resources system to forecast streamflows. The applicability of artificial neural network model to hydrologic system is analyzed and the performance is compared by statistical method with observed. Multi-layered perception was used to model rainfall-runoff process at Pyung Chang River Basin in Korea. The neural network model has the function of learning the process which can be trained with the error backpropagation (EBP) algorithm in two phases; (1) learning phase permits to find the best parameters(weight matrix) between input and output. (2) adaptive phase use the EBP algorithm in order to learn from the provided data. The generalization results have been obtained on forecasting the daily and hourly streamflows by assuming them with the structure of ARMA model. The results show validities in applying to hydrologic forecasting system.

• Journal of Electrical Engineering and Technology
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• 제6권6호
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• pp.731-741
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• 2011

Conventional methodologies (empirical, analytical, numerical, hybrid, etc.) for sizing photovoltaic (PV) systems cannot be used when the relevant meteorological data are not available. To overcome this situation, modern methods based on artificial intelligence techniques have been developed for sizing the PV systems. In the present study, the optimum PV/inverter sizing ratio for grid-connected PV systems with orientation due south and inclination angles of $45^{\circ}$ and $60^{\circ}$ in selected Algerian locations was determined in terms of total system output using type-2 fuzzy logic. Because measured data for the locations chosen were not available, a year of synthetic hourly meteorological data for each location generated by the PVSYST software was used in the simulation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.169-171
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• 2012

Although work-efficiency of construction machinery is a critical factor for estimating its workable-quantity per unit time, the coefficient figure table presented in the Poom-Sam that is used for Construction Cost Estimation of public sectors in Korea is very subjective for practical usage. In order to suggest objective work-coefficient table for a Tub Grinder, domestic and overseas documentary records were investigated and on-going construction sites were also visited. The research found that the table can be revised by means of detailing down by several factors. The research will be the foundation for applying the rapid development of Construction Equipment and technology to the appropriate cost estimations and the ground work of related studies.