• Journal of Institute of Convergence Technology
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• v.2 no.2
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• pp.59-65
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• 2012

This paper presents the study on applications of a surplus heat source. The heat is generated while hardwood charcoals are produced. We measure the temperature of the generated heat and analyze whether it can heat water or not. The analytic results show that the generated heat is useful as one of heat sources. In agricultural methods using a vinyl house, heating expenses will be saved by 10~20% when the surplus heat source is used.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.33-36
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• 2002

The purpose of this study is to develope a indicator for agricultural water use. Agricultural water is challenged by the increase of water use in the sectors of urbanization and industry and social pressure to use water in sustainable and environmentally sound way. The development of agricultural environment indicators is divided into 13 sectors, among which agricultural water use indicators include amount and intensity of agricultural water use, efficiency of agricultural water use, shortage or surplus of water use, water stress, etc.. Agricultural water use indicators provide basic data for sustainable and environmentally sound agricultural development, and also help policy decision makers to solve water shortage problems through water policy and water management measures by making the most of the total available water resources.

• Water for future
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• v.18 no.4
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• pp.317-325
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• 1985

In the analysis, monthly streamflow records atthe gauging station in Nakdong, Han and Geum river were used. Also, the fitness of monthly streamflow to Gamma and Long-normal distribution was tested by Kolomogorv-Smirnov test. The results obtained in this study can be summarized as follws (1) The fitness of monthly streamflow to two-parameter Gamma distribution was tested by Kolomorov-Smirnov test, which fits well to this Gamma distribution (2) The Run-length and Run-sum were simulated by the Gamma model. In this result, run-length and Run-sum of monthly streamflow were fit for Gamma model (3) The mean decreases (increases) the expected surplus (deficit) Run-Sum of the monthly streamflow. The higher the truncation level of negative Run-length and Run-sum the larger is the effect of mean.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.353-360
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• 2017

In this study, the design and performance test of the air to water heat pump capable of producing hot water for greenhouse heating by using the surplus solar heat inside the greenhouse and the air heat outside greenhouse as the selective heat source were conducted. The heat storage operations using the surplus solar heat and the outside air heat were designed to be switched according to the setting temperature of the greenhouse in consideration of the optimum temperature range of the crop. In the developed system, it was possible to automatically control the switching of heat storage operation, heating and ventilation by setting 12 reference temperatures on the control panel. In the selective heat storage operation with the surplus solar heat and outside air heat, the temperature of thermal storage tank was controlled variably from $35^{\circ}C$ to $52^{\circ}C$ according to the heat storage rate and heating load. The heat storage operation times using the surplus solar heat and outside air heat were 23.1% and 30.7% of the experimental time respectively and the heat pump pause time was 46.2%. COP(coefficient of performance) of the heat pump of the heat storage operation using the surplus solar heat and outside air heat were 3.83 and 2.77 respectively and was 3.24 for whole selective heat storage operation. For the comparative experiment, the heat storage operation using the outside air heat only was performed under the condition that the temperature of the thermal storage tank was controlled constantly from 50 to $52^{\circ}C$, and COP was analyzed to be 2.33. As a result, it was confirmed that the COP of the heat storage operation using the surplus solar heat and outside air heat as selective heat source and the variable temperature control of the thermal storage tank was 39% higher than that of the general heat storage operation using the outside air heat only and the constant temperature control of the thermal storage tank.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.7-9
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• 2004

The purpose of this study was to analyze the climatic water balance of the Korean peninsula using meteorological data and the evapotranspiration (ET) derived from NOAA/AVHRR. Quantifying water balance components is important to understand the basic hydrology. In this study, a simple method to estimate the ET was proposed based on a regression approach between NDVI and Morton's actual ET using NOAA/AVHRR data. The Morton's actual ET for land surface conditions was evaluated using a daily meteorological data from 77 weather stations, and the monthly averaged Morton's ETs for each land cover was compared with the monthly NDVIs during the year 2001. According to the climatic water balance analysis, water deficit and surplus distributed maps were created from spatial rainfall, soil moisture, and actual and potential ETs map. The results clearly showed that the temporal and spatial characteristics of dryness and wetness may be detected and mapped based on the wetness index.

• Journal of Aquaculture
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• v.14 no.2
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• pp.67-71
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• 2001

Phosphorus is an essential element for growth and metabolism in fish. However high levels of phosphorus in the feed can lead to poor water quality of pond, and can also be a potential source of pollution, when pond water is released to the environment. In this study phosphorus supplemented diets containing 0.0, 0.9 or 1.9% of (dicalcium) phosphate were offered to channel catfish and changes in water quality of ponds and phosphorus levels in fish were measured. Higher level of (1.9%) supplementation of phosphorus in diet resulted in higher concentration of T-P and SRP in pond waters. Also it produced negative effects on fish production by lowering feed coefficient and rate of increment in body weight. Surplus phosphorus can affect fish growth and water quality of pond.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.1
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• pp.3-9
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• 2005

The purpose of this study was to analyze the climatic water balance of the Korean peninsula using meteorological data and the evapotranspiration (ET) derived from NOAA/AVHRR, Quantifying water balance components is important to understand the basic hydrology, In this study, a simple method to estimate actual ET was proposed based on a regression approach between NDVI and Morton's actual ET using NOAA/AVHRR data, The Mortons actual ET for land surface conditions was evaluated using a daily meteorological data from 77 weather stations, and the monthly averaged Morton's ETs for each land cover was compared with the monthly NDVIs during the year 2001. According to the climatic water balance analysis, water deficit and surplus distributed maps were created from spatial rainfall, soil moisture, and actual and potential ETs map, The results clearly showed that the temporal and spatial characteristics of dryness and wetness may be detected and mapped based on the wetness index.

• Journal of Hydrogen and New Energy
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• v.34 no.2
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• pp.91-99
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• 2023

Participation in power trading using surplus power is considered a business model active in the domestic energy trade market, but it is limited only if the legal requirements according to the type, capacity, and use of the facilities to be applied for are satisfied. The hydrogen residential demonstration model presented in this paper includes solar power, energy storage system (ESS), fuel cell, and water electrolysis facilities in electrical facilities for private use with low-voltage power receiving system. The concept of operations strategy for this model focuses on securing the energy self-sufficiency ratio of the entire system, securing economic feasibility through the optimal operation module installed in the energy management system (EMS), and securing the stability of the internal power balancing issue during the stand-alone mode. An electric facility configuration method of a hydrogen residential complex demonstrated to achieve this operational goal has a structure in which individual energy sources are electrically connected to the main bus, and ESS is also directly connected to the main bus instead of a renewable connection type to perform charging/discharging operation for energy balancing management in the complex. If surplus power exists after scheduling, participation in power trading through reverse transmission parallel operation can be considered to solve the energy balancing problem and ensure profitability. Consequentially, this paper reviews the legal regulations on participation in electric power trading using surplus power from hydrogen residential models that can produce and consume power, gas, and thermal energy including hybrid distributed power sources, and suggests action plans.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.126-129
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• 2008

Using a surplus head in presented water supply pipes, we have studied to improve the operating efficiency of small hydro generator, which was chosen for a test model with Sung-Nam and Bo-Ryong small hydro power plant. With regard to power control and countermeasure of water hammer impact, Finally we have represented the optimal control method through the synthetical analysis of existing system symptoms, operation efficiency, the effect of water hammer impact and system configuration.

• Journal of Environmental Science International
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• v.25 no.3
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• pp.447-456
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• 2016

Access to clean and affordable water is one of the fundamental human rights because water is essential to life and a foundation for socioeconomic development of any country in the world. Despite the efforts to secure water supply in Burundi, the amount of water supplied by public utilities does not meet the demand of the population because population keeps increasing with fluctuation of weather conditions. This study selected north Bujumbura that is a sprawling new residential area in the western part of Burundi as a case to investigate the potential of rainwater harvesting in meeting water demand of the country. Based on a long-term average monthly precipitation in the region, the rainwater harvesting potential was assessed as a function of roof sizes, number of households, and runoff coefficients of roof materials. For the entire region of north Bujumbura, the current water supply capacity of the local water company combined with the rainwater harvesting potential resulted in the water surplus of $468,604.1m^3/yr$. Although three communes among them still showed water deficit in dry season, they still got help from rainwater to relieve their water shortage. This suggests that at the regional scale, proper storages and water quality control for harvestable rainwater could contribute to relieving the regional water shortage and allow the population growth.