• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.5
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• pp.73-80
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• 1995

The uses of stage-storage curve function are diverse in irrigation reservoirs. The curve functions would be used to determine the optimal size of spillway length and the inundation area above full water level based on the flood routing in reservoirs. In addition, the curve function would he used to transform the stage to the storage for the reservoir water management, in which the storage is the supply water. Besides those, the curve is necessary for the planning of dredging, the estimation of the effective and the dead storage, the drought management by reservoir, etc. The curve function data, however, are almost unavailable for these purposes. According to the statistics, about 74% of the 2, 900 resevoirs which are maintained by Farm Land Improvement Association have no more effective data. Therefore, the simulation of the curve function could be better alternative. The curve functions were simulated derivating the regression equations based on the basin relief ratio and the effective depth. The results of the verification show the enough reliability of the application to generate the curve function in some reservoirs which do not have the surveyed stage-storage data. Also, even though the averaged curve function would be applicated without the basin relief ratio data, the result shows that the simulated curve is closer to the real one than the linear function by only the existing effective storage data.

• Magazine of the Korean Society of Agricultural Engineers
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• v.18 no.2
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• pp.4116-4120
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• 1976

With the use of many rivers increased nearly to the capacity, the need for information concerning daily quantities of water and the total annual or seasonal runoff has became increased. A systematic record of the flow of a river is commonly made in terms of the mean daily discharge Since. a single observation of stage is converted into discharge by means of rating curve, it is essential that the stage discharge relations shall be accurately established. All rating curves have the looping effect due chiefly to channel storage and variation in surface slope. Loop rating curves are most characteristic on streams with somewhat flatter gradients and more constricted channels. The great majority of gauge readings are taken by unskilled observers once a day without any indication of whether the stage is rising or falling. Therefore, normal rating curves shall show one discharge for one gauge height, regardless of falling or rising stage. The above reasons call for the correction of the discharge measurements taken on either side of flood waves to the theoretical steady-state condition. The correction of the discharge measurement is to consider channel storage and variation in surface slope. (1) Channel storage As the surface elevation of a river rises, water is temporarily stored in the river channel. There fore, the actual discharge at the control section can be attained by substracting the rate of change of storage from the measured discharge. (2) Variation in surface slope From the Manning equation, the steady state discharge Q in a channel of given roughness and cross-section, is given as {{{{Q PROPTO SQRT { 1} }}}} When the slope is not equal, the actual discharge will be {{{{ { Q}_{r CDOT f } PROPTO SQRT { 1 +- TRIANGLE I} CDOT TRIANGLE I }}}} may be expressed in the form of {{{{ TRIANGLE I= { dh/dt} over {c } }}}} and the celerity is approximately equal to 1.3 times the mean watrr velocity. Therefore, The steady-state discharge can be estimated from the following equation. {{{{Q= { { Q}_{r CDOT f } } over { SQRT { (1 +- { A CDOT dh/dt} over {1.3 { Q}_{r CDOT f }I } )} } }}}} If a sufficient number of observations are available, an alternative procedure can be applied. A rating curve may be drawn as a median line through the uncorrected values. The values of {{{{ { 1} over {cI } }}}} can be yielded from the measured quantities of Qr$.$f and dh/dt by use of Eq. (7) and (8). From the 1/cI v. stage relationship, new vlues of 1/cI are obtained and inserted in Eq. (7) and (8) to yield the steady-state discharge Q. The new values of Q are then plotted against stage as the corrected steadystate curve.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2236-2244
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• 2018

We make optimal consecutive offer curves for an energy storage system (ESS) integrated wind power producer (WPP) in the co-optimized day-ahead energy and regulation markets. We build the offer curves by solving multi-stage stochastic optimization (MSSO) problems based on the scenarios of pairs consisting of real-time price and wind power forecasts through the progressive hedging method (PHM). We also use the rolling horizon method (RHM) to build the consecutive offer curves for several hours in chronological order. We test the profitability of the offer curves by using the data sampled from the Iberian Peninsula. We show that the offer curves obtained by solving MSSO problems with the PHM and RHM have a higher profitability than offer curves obtained by solving deterministic problems.

• Journal of Korean Society of Rural Planning
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• v.9 no.4 s.21
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• pp.1-7
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• 2003

This study was conducted to seek the effective water management method of the irrigation reservoirs. Joongpyong reservoir was selected for the hydrologic monitoring, and investigated from May in 1999 to December in 2001. The water level and amount of outlet discharge were measured, the stage discharge equation as a rating curve was induced, and which were compared to the irrigation water requirements calculated by a daily simulation model. The water balance of Joongpyong reservoir was analyzed, mainly on the reservoir storage ratio during irrigation period. Comparing the observed storage and simulation data, the results of the simulation were well agreed with the measured data.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.315-317
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• 2001

This paper studies for the optimal operation of BESS. The goal must be optimized electricity charge of the customer sides owned time-of-use rates in this paper. Therefore, the least of cost is caused by BESS installation, Multi-Pass Dynamic Programming (MPDP) algorithm is applied to the customer for the optimal operation determination in this paper. It is to solve the optimal solution under the constraints. No matter how become one stage in general, problem is divided into several stage in series in this algorithm. Regardless of the decision step, MPDP is only accomplished based on the state of stage in the present. To investigate the efficiencies of the algorithm, it is applied the typical load curve to the cutomer owned Time-Of-Use(TOU). Result shows that the maximun economic benefits of the battery energy storage system can be achieved by the purposed algorithm.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.20-30
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• 2008

This study is to analyse the hydrological behavior of agricultural reservoir using SWAT model. For the upsteam watershed of Gongdo water level gauge station in Anseongcheon watershed, the streamflows at 2 reservoir (Gosam and Geumgwang) locations and Gongdo station were simulated with reservoir inclusion and exclusion. The daily water surface area and storage have been calculated considering the stage-storage curve function of the reservoir. Afterwards, the reservoir operation module in SWAT was modified from original module in SWAT for daily reservoir discharge simulated by water balance equation. Model validation results were Nash-Sutcliffe model efficiency coefficients value of 0.55, root mean square error value of 2.33 mm/day. On the other hand, the simulation results of two reservoir exclusion were Nash-Sutcliffe model efficiency coefficients value of 0.37, root mean square error value of 2.91 mm/day. The difference of Nash-Sutcliffe model efficiency coefficients between the simulation results of two reservoir inclusion and exclusion at Gongdo station was 0.18. This is caused by the storage and release operation of agricultural reservoirs for the runoff occurred at 2 reservoir watersheds.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.41-46
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• 2018

Six sigma methodology is the management tools not only can cause productivity enhancement through the quality control and cost reduction of products and services but also can be applied to various activities of corporates such as research and development. Development of high-density information storage media and devices is indispensible to accomplish the information convergence era. In this paper, we report the case of applying six sigma methodology and tools to the development project of high-density information storage media. The standard DMAIC process was applied to the project and pursuing goals and tools and results in each stage were explained in detail. By adopting the methodology, we could establish fabrication methods of information storage media of recording density higher than $250Gb/in^2$ with high uniformity and reproducibility. The magnetic property and performance of fabricated media were confirmed through measurement of the magnetic hysteresis curve.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2227-2235
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• 2018

Under the current policies and compensation rules in South Korea, Photovoltaic (PV) generation supplier can maximize the profit by combining PV generation with Energy Storage System (ESS). However, the existing operational strategy of ESS is not able to maximize the profit due to the limitation of ESS capacity. In this paper, new ESS scheduling algorithm is introduced by utilizing the System Marginal Price (SMP) and PV generation forecasting to maximize the profits of PV generation supplier. The proposed algorithm determines the charging time of ESS by ranking the charging schedule from low to high SMP when PV generation is more than enough to charge ESS. The discharging time of ESS is determined by ranking the discharging schedule from high to low SMP when ESS energy is not enough to maintain the discharging. To compensate forecasting error, the algorithm is updated every hour to apply the up-to-date information. The simulation is performed to verify the effectiveness of the proposed algorithm by using actual PV generation and ESS information.

• Journal of Korean Society of Rural Planning
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• v.2 no.2
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• pp.91-102
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• 1996

Monitoring techniques for afro-ecological environments were studied, Hydrologic and ecological components in conjunction with water quality were monitored in the Balkan watershed. The hydrologic monitoring program consists of four water level gauging stations along creeks and stream at the watershed having 26.5 km2. Stage - storage relationship of reservoir, rainfall amount of the watershed, and rating curve of the stream gauging stations were established. Soil type, land use, hydrologic soil group, population and economic activities within the watershed were surveyed. Water quality data from the streams were sampled weekly and chemical analysis was conducted. Temporal variations of water quality were investigated and water quality map of each reach of stream was made to identify spatial variations. Seasonal and spatial variations of vegetation densities along stream in the watershed were investigated using grid, Density variations of insect species such as arthropod, flying insect, spider spices, rice insects were also monitored to determine seansonal surveying density. These monitored data will be used to develop monitoring techi%ues and afro - ecological environment models.

• Applied Biological Chemistry
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• v.41 no.6
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• pp.437-441
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• 1998

The effects of sucrose fatty acid ester (SE, 1% w/w) and glycerin (GL, 1% v/w) additions, storage temperature$(0,\;20\;and\;70^{\circ}C)$, and time $(0{\sim}6\;day)$ on texture properties, hardness(H), cohesiveness(O), chewiness(C) and rheological property(R) of Baikseolgi were studied. The H of Baikseolgi increased sharply in the early stage of storage at 0 and $20^{\circ}C$, while increased gently at $70^{\circ}C$ with increasing storage time. After 6 days of storage, the H of Baikseolgi at $20^{\circ}C$ had a little lower than that at $0^{\circ}C$. However, the H of Baikseolgi at $70^{\circ}C$ was 10.7% of that at $0^{\circ}C$. The addition of GL had greater effect on the reduction of H than that of SE. The H of control, SE and GL additions were 336, 216 and $$174\;g_f, respectively, after 6 days at $70^{\circ}C$. The O of Baikseolgi at $70^{\circ}C$ were higher than those at $0^{\circ}C$. The O of GL added Baikseolgi had the highest value and the second and the third were SE added and control, respectively. The O of Baikseolgi decreased with increasing storage time. The C of Baikseolgi of increased with increasing storage time, which had similar curve patterns to the H of Baikseolgi. Instantaneous stress and equilibrium stress of Baikseolgi decreased with increasing storage temperature. The affection of viscous element increased and that of elastic element decreased with increasing storage temperature.