• Journal of the Korean Solar Energy Society
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• v.37 no.6
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• pp.59-68
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• 2017

In accordance with the policy of local government, the large scale of wind farms have been installed in Jeju power system. However, The intermittent characteristics of wind power output may cause grid voltage and frequency variation, especially in weak power system. One of the solution to solve this problem is installation of Energy storage system (ESS). In this case, the ESS will regulate the active power generated from wind farm to mitigate fluctuation. Actually, the local government of Jeju island constructed ESS connected to Hangwon wind turbine in 2016. From this point, this paper analyzes requirement capacity of ESS to mitigate wind power fluctuation based on measured data from Hangwon wind turbine and ESS. The simulation results will be carried out by Matlab program.

• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.57-65
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• 2011

The wake generated by a wind turbine has an effect on performance of a downstream wind turbine as well as mechanical loads. This paper investigated characteristics of fatigue load at the blade root due to the wake effects and quantitatively analyzed its effects at operating condition of a 5MW tripod offshore wind turbine using Bladed 4.1 software. The wake effects was studied the way the wake's center position move from the rotor center to the blade tip to the far-away position where the wake doesn't affect the wind turbine. When wake's center was located on the blade tip or the rotor center, damage equivalent fatigue load was higher than other positions. It was up to 10~14% compared to those of non-wake case. Results of this study would be helpful to design wind turbines and wind farms to have lifetimes more than 20 years of the wind turbine.

• 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.

• Journal of the Korean Solar Energy Society
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• v.35 no.3
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• pp.1-8
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• 2015

The MERRA reanalysis data provided online by NASA was applied to predict the monthly energy productions of Donghai Bridge Offshore wind farms in China. WindPRO and WindSim that are commercial software for wind farm design and energy prediction were used. For topography and roughness map, the contour line data from SRTM combined with roughness information were made and used. Predictions were made for 11 months from July, 2010 to May, 2011, and the results were compared with the actual electricity energy production presented in the CDM(Clean Development Mechanism)monitoring report of the wind farm. The results from the prediction programs were close to the actual electricity energy productions and the errors were within 4%.

• Korean Journal of Veterinary Research
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• v.56 no.4
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• pp.215-221
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• 2016

Due to the shortage of the fingerling/juvenile mud loach, Misgurnus mizolepis in Korea, these fish have been imported from China. However, the mortality rate during and after their transportation is very high. In this study, we examined various physiological and histological parameters to evaluate the effect of salt treatment on the survival and recovery of mud loaches in holding farms during the quarantine process. Glucose, osmolality, $Na^+$, $Cl^-$, and histological changes were assessed for three different salinities. Non-treated fish (control 0.0%) exhibited lower levels of osmolality, and $Na^+$ and $Cl^-$ concentrations compared with those kept in solar salt solution (0.5% and 1.0%). Glucose levels in control fish were higher than those in fish exposed to 0.5% and 1.0% solar salt solution. Histologically, control fish showed thinner epidermis of skin, branchial hyperplasia and lamellar fusion with an abundance of eosinophilic granule cell-like cells. After solar salt solution treatment, damaged gill structures in the fish almost recovered within 5 days. The present study demonstrates that mud loaches transported from China suffer from skin and gill damage and physiological dysfunction which may increase the mortality and morbidity. Moreover, saline treatment might alleviate the stress responses and ionic/osmotic imbalances, and help heal gill damage.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.278-282
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• 2012

Photovoltaic systems have emerged to be one of the cleanest energy systems. Therefore, many large scale solar parks and PV farms have been built to prepare for the post fossil fuel ages. However, due to their large scale, to efficiently manage and operate PV systems, they need to be visually monitored within the range of infrared ray through the Internet. To satisfy this need, the efficient implementation of a high performance video compression standard is required. This paper therefore presents an implementation of H.264 motion estimation, which is one of the most data-intensive and complicated functions in H.264. To achieve this, this work implements vector instructions in hardware and incorporates them in a generic RISC processor architecture, thus increasing the processing speed while minimizing hardware and software design efforts. Extensive simulation results show that this proposed implementation can process motion estimations up to 13 times faster.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.2
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• pp.103-108
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• 2013

Packaging of solar salts produced in Korea and Japan were evaluated and compared each other in terms of packaging design such as package types, colors and graphics. The standing pouch type in plastic film was most popular for the Korean salts regardless of the package capacity. But the same type was common only for the lower package capacity of 300 g or less while the plastic film pouch was prevalent for the higher capacity for the Japanese salts. White and brown were dominant colors for the Korean solar salts reminding us of salt farms and the foreshore respectively and strengthening its color identity. White, blue and red were used for the dominant, assort and accent colors respectively for the Japanese salt packaging. Salt farmers and the foreshore are often represented as the main package graphics for the Korean solar salts while the wave symbolising the sea was found frequently for the Japanese ones. The word of 'Shinan' was involved the most in the brand names of the Korean salts and the sea was appeared very often in those of the Japanese ones.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.3
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• pp.141-148
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• 2021

Agrivoltaic systems, also called solar sharing, stated from an idea that utilizes sunlight above the light saturation point of crops for power generation using solar panels. It is expected that agrivoltaic systems can realize climate smart agriculture by reducing evapotranspiration and methane emission due to the reduction of incident solar radiation and the consequent surface cooling effect and bring additional income to farms through solar power generation. In this study, to evaluate that agrivoltaic systems are suitable for realization of climate smart agriculture, we conducted agro-environmental observations (i.e., downward/upward shortwave/longwave radiations, air temperature, relative humidity, water temperature, soil temperature, and wind speed) in a rice paddy under an agrivoltaic system and compared with the environment outside the system using automated meteorological observing systems (AMOS). During the observation period, the spatially averaged incoming solar radiation under the agrivoltaic system was about 70% of that in the open paddy field, and clear differences in the soil and water temperatures between the paddy field under the agrivoltaic system and the open paddy field were confirmed, although the air temperatures were similar. It is required in the near future to confirm whether such environmental differences lead to a reduction in water consumption and greenhouse gas emissions by flux measurements.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.593-602
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• 2020

Recently, as research on smart farms has been actively conducted, systems for efficiently cultivating crops have been introduced and various energy systems using renewable energy such as solar, geothermal and wind power generation have been proposed to save the energy. In this paper, we propose a new and renewable energy convergence system for crops that provides energy independence and improved crop cultivation environment. First, we present LPWA-based communication node and gateway for ICT-based data collection. Then we propose an integrated monitoring server that collects energy data, crop growth data, and environmental data through a communication node and builds it as big data to perform optimal energy management that reflects the characteristics of the environment for cultivating crops. The proposed system is expected to contribute to the production of low-cost, high-quality crops through the fusion of renewable energy and smart farms.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.695-702
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• 2020

Recently, as research on smart farms has been actively conducted, indoor environment control, such as a green house, has reached a high level. However, In the field of forestry where cultivation is carried out in outdoor, the use of ICT is still insufficient. In this paper, we propose LPWA-based forest growth environment collection and big data analysis system using ICT technology. The proposed system collects and transmits the field cultivation environment data to the server using small solar power generation and LPWA technology based on the oneM2M architecture. The transmitted data is constructed as big data on the server and utilizes it to predict the production and quality of forest products. The proposed system is expected to contribute to the production of low-cost, high-quality crops through the fusion of renewable energy and smart farms. In addition, it can be applied to other industrial fields that utilize the oneM2M architecture and monitoring the growth environment of agricultural crops in the field.