• Food Science and Preservation
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• v.17 no.4
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• pp.444-450
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• 2010

We investigated the quality of Dombaeki (shark meat) treated without salting (NS), with salting (S), air-packed (A), and vacuum-packed (V), during storage at $4^{\circ}C$ and $-18^{\circ}C$. We explored water holding capacity, elasticity, total bacterial counts, pH, titratable acidity level, volatile basic nitrogen (VBN) value, and drip loss. Water holding capacity and elasticity values were better when salting and vacuum-packaging were employed than when samples were not salted and were packaged in air. The total bacterial counts in SV meat were significantly lower than in other samples. The pH of all samples increased slowly during storage, and the pH values of NSA samples were significantly higher than the pH values of other samples. The VBN level and drip loss of SV meat were the lowest of all samples during storage. The results show that salted vacuum-packed meat was of better quality than that stored without salting, and air-packed, regardless of storage temperature.

• Clean Technology
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• v.27 no.1
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• pp.85-92
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• 2021

A solar water battery is a system that generates power using solar energy. It is a combination of photoelectrochemical cells and an energy storage system. It can simultaneously convert and store solar energy without additional external voltage. Solar water batteries consist of photoelectrodes, storage electrodes and counter electrodes, and their properties and combination are important for the performance and the efficiency of the system. In this study, we tried to find the effect that changing the components of solar water batteries has on its system. The effects of the counter electrode during discharge, the kinds of photoelectrode and storage electrode materials, and electrolytes on the solar energy conversion and storage capacitance were studied. The optimized composition (TiO2 : NaFe-PB : Pt foil) exhibited 72.393 mAh g-1 of discharge capacity after 15 h of photocharging. It indicates that the efficiency of solar energy conversion and storage is largely affected by the configuration of the system. Also, the addition of organic pollutants to the chamber of the photoelectrode improved the battery's photo-current and discharge capacity by efficient photoelectron-hole pair separation with simultaneous degradation of organic pollutants. Solar water batteries are a new eco-friendly solar energy conversion and storage system that does not require additional external voltages. It is also expected to be used for water treatment that utilizes solar energy.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.1-6
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• 2017

Total capacity of pumped hydro storage(PHS) in Korean power system reaches 4,700MW, though the share of it is about 4.56% of total capacity The Unit Commitment program, E-terracommit which is used for the operational purpose by KPX, includes the PHS model. But the model has a defect that it does not include the information of water level of upper reservoir. Therefore two types of improved the PHS models are represented in this paper. The first model is a optimized model by connecting the upper reservoir water level to the non-spinning reserve. The other model is to have priority allocate both the PHS and combined cycle generator for non-spinning reserve. The proposed two models and the E-terracommit model is compared and resulting to have improvement in estimating non-spinning reserve when using the proposed models.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.1-7
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• 2010

This study was carried out to investigate the effect of hydro power factors (e.g., irrigation area, watershed area, active storage, gross head) on annual generation capacity and operation ratio for agricultural reservoirs in Chungbuk Province with active storage of over 1 million $m^3$. The annual generation capacity and operation ratio were estimated using HOMWRS (Hydrological Operation Model for Water Resources System) from last 10-year daily hydrological data. The correlation coefficients between annual generation capacity and the hydro power factors except gross head were high (over 0.87), but the correlation coefficients between operational rate and the factors were low (below 0.28). The optimum multiple regression equations of the annual generation capacity were expressed as the functions of watershed area, active storage, and gross head. Also, the simple regression equation of annual generation capacity was expressed as a function of watershed area. The average relative root-mean-square-error (RRMSE) between observed and estimated values by the optimum multiple regression equations was smaller than that by the simple regression equation, suggesting that the former has more accuracy than the latter.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.768-773
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• 2009

A numerical study has been performed to investigate the thermal Performance of Solar heating system with baffle type of storage tank by using the commercial code TRNSYS. As a result, the solar fraction depends strongly on the efficiency and heat loss coefficient of solar collector as well as the heating capacity of house and the water temperature supplied to the shower. In addition, the solar fraction has been basically ranked to higher level in baffle type of storage tank than typical type of single storage tank for the range of operation condition.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.11
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• pp.805-811
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• 2010

A numerical study has been performed to investigate the thermal performance of solar heating system with baffle type of storage tank by using the commercial code TRNSYS. As a result, the solar fraction depends strongly on the efficiency and heat loss coefficient of solar collector as well as the heating capacity of house and the water temperature supplied to the shower. In addition, the solar fraction has been basically ranked to higher level in baffle type of storage tank than typical type of single storage tank for the range of operation condition.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.4
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• pp.97-105
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• 1998

The goal of the present research was to develop a mean to determine indices of drought warning and emergency necessary to manage drought and establish water supply contingency plan for the municipal and industrial water supply system in urban areas. To do this, we worked on the Sayun catchment which is the main water source of Ulsan and used measured hydrologic data (storage, inflow, supply, outflow) from 1980 to 1996. The indices of drought calculated by the method of Phillips drought index based only on monthly precipitation do not pertinently represent drought phenomena in case water supply is from dam or reservoir in an urban area. Therefor, we developed the drought index technique including inflow, storage, outflow and supply which are the chief factors of drought management. The result showed that the method of Phillips drought index considering the capacity of water supply was excellent when applied to practical drought phenomena.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.3
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• pp.93-101
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• 2016

Reservoir area and reservoir capacity must be evaluated for reservoir management such a water supply, water-purity control and so on. In this paper, the reservoir area and reservoir capacity according to the level of storage range of water(149~156 El.m) could be calculated by using TIN data model of study area, Gyoyeon reservoir, TIN data model was made of DSM which was created by using UAV and GCP survey. From the results of applying the various functions to reservoir area and capacity, reservoir area and reservoir capacity according to the level of storage range of water showed the highest coefficient of determination of 0.97 in fourth-order polynomial, and 0.99 in second-order polynomial, respectively. Thus, it could be expected the efficient reservoir management by estimating reservoir area and capacity curve equation through UAV photogrammetry.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.9 no.2
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• pp.93-103
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• 1980

A small domestic solar water heating system in thermosyphonic flow was tested in Seoul. The system consisted of four flat plate aluminium roll bond type collectors of total effective area $3.28m^2$ and a $280{\iota}$ storage tank. It was tilted $52^{\circ}$ relative to the horizon. And the collector plate, collector tube and storage tank were equiped with 14 thermocouples. As the results, the following facts were found; 1) To provide water at $55^{\circ}C$ for a family of four in Seoul, a collector area of $3-4m^2$ and a storage capacity of $180{\iota}- 200{\iota}$ are suggested. And this system can supply hot water at above $45^{\circ}C$ day about. 2) In the late afternoon hours, it might be advantageous to stop the flow in the system as heat losses to the environment increase unduly. 3) Without any hot water consumption throughout the day, water temperature distributions inside the storage tank was found almost linear. This indicates essentially no mixing inside the storage tank. 4) In case of a small domestic solar water heating system, it is better to employ a single transparent cover rather than double one.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.279-286
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• 1998

The south-western part of Korea is situated in an unbalance of water supply and demand relating to the Keum, Mankyung, Dongjin and Youngsan River and their estuary reservoirs. For example, the Keum River estuary reservoir is discharging the larger amount of yearly runoff into the sea due to the small storage capacity, while Saemankeum estuary reservoir which is under construction, has the smaller runoff amount comparing with its storage capacity, And the downstream area of the Youngsan River, such as Youngkwang, Youngam are deficient in water due in larger demand and smaller supply. In order to solve the above unbalanced water supply and demand and also to improve the water use efficiency, the Hierarchical Operation Model for Multi-reservoir System(HOMMS) has been developed and applied to analyze the multi-reservoir operation assuming that the above reservoirs were linked each other. The result of this study shows that 2,148MCM of annual additional water requirement for agricultural and rural water demands are required in this region at 2011 of target year, and these demands can be resolved by diverting and reusing 1,913MCM of the released water from the estuary reservoirs into the sea.