• Journal of Wind Energy
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• v.9 no.4
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• pp.32-39
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• 2018

In this study, the annual power production of a wind farm according to obstacles and wind data was predicted for the Garyeok-do wind farm in the Saemangeum area. The Saemangeum Garyeok-do wind farm was built in December 2014 by the Korea Rural Community Corporation. Currently, two 1.5 MW wind turbines manufactured by Hyundai Heavy Industries are installed and operated. Automatic weather station data from 2015 to 2017 was used as wind data to predict the annual power production of the wind farm for three consecutive years. For prediction, a commercial computational fluid dynamics tool known to be suitable for wind energy prediction in complex terrain was used. Predictions were made for three cases with or without considering obstacles and wind direction errors. The study found that by considering both obstacles and wind direction errors, prediction errors could be substantially reduced. The prediction errors were within 2.5 % or less for all three years.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.180.2-180.2
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• 2010

The purpose of this research is to analyze the sensitivity of WindSIM in complex terrain. As the flat areas for wind turbine installation become scarce globally, it becomes inevitable to install wind turbines in complex terrain. In order to predict annual energy production (AEP) in a more precise manner in complex terrain, it is of great importance to conduct such research. Three parameters: reference velocity, roughness and resolution have been chosen to see to which parameter WindSIM was the most sensitive in terms of annual energy production in complex terrain. By fixing two parameters and setting one parameter as a variable, it could be easily found that how annual energy production was effected by the change in each parameter.

• International Journal of Fluid Machinery and Systems
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• v.10 no.3
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• pp.264-273
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• 2017

In order to be able to predict the maximum Annual Energy Production (AEP) for tidal power plants, an AEP optimization tool based on Evolutionary Algorithms was developed by ANDRITZ HYDRO. This tool can simulate all operating modes of the units (bi-directional turbine, pump and sluicing mode) and provide the optimal plant operation that maximizes the AEP to the control system. For the Swansea Bay Tidal Power Plant, the AEP optimization evaluated all different hydraulic and operating concepts and defined the optimal concept that led to a significant AEP increase. A comparison between the optimal plant operation provided by the AEP optimization and the full load operating strategy is presented in the paper, highlighting the advantage of the method in providing the maximum AEP.

• Journal of the Korean Solar Energy Society
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• v.24 no.3
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• pp.1-7
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• 2004

Using WAsP, which is PC-program for the vertical and horizontal extrapolation of wind data, annual energy production as well as wind energy density has been predicted for Haengwon wind farm in Jeju island. The predicted results were compared with real data derived from wind turbines in Haengwon wind farm. As the results, in order to produce more electric power, new wind turbines should be located along coastal line, which has comparatively high wind energy density. Also, the roughness length should be inputted to the Map Editor program for better agreement with real annual energy production.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.6
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• pp.558-565
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• 2013

This paper presents how to determine AEP(Annual Energy Production) by a small wind turbine in DuckjeokDo island. Evaluation of AEP is introduced to make a self-contained island including renewable energy sources of wind, solar, and tidal energy. To determine the AEP in DuckjeokDo island, a local wind data is analyzed using the annual wind data from Korea Institute of Energy Research firstly. After the wind data is separated in 12-direction, a mean wind speed at each direction is determined. And then, a small wind turbine power curve is selected by introducing the capacity of a small wind turbine and the energy production of the wind turbine according to each wind direction. Finally, total annual wind energy production for each small wind turbine can be evaluated using the local wind density and local energy production considering a mechanical energy loss. Throughout the analytic study, it is found that the AEP of DuckjeokDo island is about 2.02MWh/y and 3.47MWh/y per a 1kW small wind turbine installed at the altitude of 10 m and 21m, respectively.

• Asian Journal of Turfgrass Science
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• v.11 no.1
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• pp.33-43
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• 1997

The production and decomposition rate of litters of major forest trees in Korea, such as Quercus acutissima, Quercus mogolica Robinia pseudoacacia Pinus rigida, Pinus thunbergiana, Abies koreana,Phy'llostackys reticulata, were estimated by Olson model. The amount of mineral nutrients in litters and soil were measured, and the relationships among them were studied. The annual litter production was the most in the forest of broadleaved deciduous trees and the least in the forest of monocotyledonous trees. The decomposition rate of broadleaved deciduous litters was higher than that of coniferous litters and lower than that of R. pseudoacacia litters. The time required for the decomposition of half of the accumulated organic matter of R.pseudoacacia litter, Quercus litter, P. rigida litter, Ph. reticulata litter, P. thunbergiana litter and .4.koreana litter in the forest stands were 1.263 years, 2.290~2.365 years, 2.644 years, 4.660 years,4.750 years, 6.699 years respectively. The amounts of N in litters and the amounts of N returned to the soil in the forests of R. pseudoacacia. Quercus, Pinus were proportional to the decay rate of organic matter. Key words: Annual litter production, Decomposition rate.

• Journal of the korean society of oceanography
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• v.39 no.3
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• pp.186-196
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• 2004

Since seagrasses are highly productive and provide a source of organic carbon for a wide variety of marine organisms in coastal and estuarine ecosystem, accurate assessment of seagrass production is critical to understand the functions and values of seagrasses in these ecosystems. Zieman's leaf marking technique has been mostly used to estimate seagrass leaf production rates. However, inherent problems on the traditional leaf marking technique have been discussed by the several researchers, and these problems can cause underestimation of seagrass production. To develop an accurate and reliable assessing method for seagrass production, production rates of eelgrass, Zostera marina in three bay systems on the south coast of the Korean peninsula were estimated using the conventional leaf marking technique and the plastochrone method. The plastochrone method has been recently suggested as an effective method for reliable assessments of seagrass production. In the present study, leaf production rates estimated by the plastochrone method were significantly higher than the rates derived from the traditional leaf marking technique. Annual eelgrass leaf production assessed using the leaf marking technique was about 65 to 89% of the estimated production using the plastochrone method. The differences in annual productions between assessment techniques imply that the conventional leaf marking technique significantly underestimated eelgrass leaf production. Total eelgrass productions estimated using the plastochrone method in the present study sites were about 600 to 806 g DW $m^{-2} y^{-l}$, and below-ground production accounted for about 20 to 23% of the total production. The plastochrone method was suggested to be an effective and accurate assessing method for eelgrass production.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.1-7
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• 2003

This paper considers an Integrated one-vendor multi-buyer production-inventory model where the vendor manufactures multiple products In lot at Her associated finite production rates In the model. It is allowed for earth product to be shipped In lot to the buyers before the whole product production is not completed yet. Each product lot is dispatched to the associated buyer In a number or shipments. The buyers consume their products at fixed rates. The objective is to the production and shipment schedules in the Integrated system. which minimizes the mean total annual cost per unit time. The mean total annual cost consists or production setup cost inventory holding cost and shipment cost. For the model, an Iterative optimal solution procedure with shipment consolidation policy incorporated is derived. It is then tested through numerical experiments to show how efficient and effective He shipment consolidation policy is.

• Journal of the Korean Solar Energy Society
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• v.35 no.2
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• pp.33-41
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• 2015

A feasibility study to estimate annual energy production of an offshore wind farm was performed using MERRA reanalysis data. Two well known commercial codes commonly used to wind farm design and power prediction were used. Three years of MERRA data were used to predict annual energy predictions of the offshore wind farm close to Copenhagen from 2011 to 2013. The availability of the wind farm was calculated from the power output data available online. It was found from the study that the MERRA reanalysis data with commercial codes could be used to fairly accurately predict the annual energy production from offshore wind farms when a meteorological mast is not available.

• The Korean Journal of Ecology
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• v.21 no.6
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• pp.809-814
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• 1998

Changes of annual seed production related to climate change were studied for 12 years in Piagol, a riparian valley in Mt. Jiri. Sixty-four seed traps (sized 0.5 ${\times}$ 0.5 $m^{2}$) were set up on the forest floor of surveyed area. Seeds were collected from these traps at an interval of 15 days from September to November since 1984. Vegetation of the study area was mainly consisted of the naturally regenerated Carpinus tschonoskii in the tree layer. Acer mono, Quercus serrata, Carpinus laxiflora and Symplocos chinensis also appeared in the same layer. Maximum production occurred in 1984 and 1994. As a result of comparing seed production with local climate factors for 12 years, seed productivity and the year of maximum production of Carpinus forest were merely related with precipitation, air temperature and duration of sunshine among local climate factors. Duration of sunshine was, however, not contributed to periodically high productivity of seed of riparian valley carpinus forest.