수질오염총량관리 관거월류부하 변화에 따른 배출부하량 산정방법

박준대 ( Jun Dae Park ),오승영 ( Seung Young Oh ),최옥연 ( Ok Youn Choi ) 한국물환경학회 2011 한국물환경학회지 Vol.27 No.3

The quantity of a discharge load can change with changes in rainfall in the area with a combined sewer system (CSS). To evaluate the implementation appropriately in the management of total maximum daily loads (TMDLs), the effects of rainfall changes should be considered in the estimation of the discharge load. The rainfall condition for the estimation of the discharge load in a certain year should be standardized to the same rainfall condition as that of the reference year. However, the calculation process is very complicated with its potential limitations. This study investigated and developed relatively simple methods for estimating the discharge load. Load conversion method (LCM) is designed to convert the discharge load under the current rainfall condition into that of the reference rainfall conditions. Simple rainfall data method (SRDM) is to simplify the estimation process of the discharge load by the simple conversion of rainfall data. These methods were applied to calculate the discharge load and examine the estimation results. From the results of this study the application of these methods may be useful for estimating the discharge load in the TMDL process.

Evaluation of Applicability of the ESTIMATOR Model for the Analysis of Nutrient Load Characteristics

Shin, Yong-Chul,Heo, Sung-Gu,Lim, Kyoung-Jae,Choi, Joong-Dae The Korean Society of Agricultural Engineers 2005 한국농공학회논문집 Vol.47 No.7

It has been well-known that the Nonpoint Source (NPS) pollutions are the primary contributors to water quality degradation in the receiving water bodies as well as the Point Source (PS) pollutions. To develop an effective management practice for water quality improvement, pollutant loads must be first estimated. In many studies, the Numeric Integration (NI) method has been used because of its ease of application, irrespective of the total number of samples collected for each storm event. Thus, there have been needs for more accurate pollutant load estimation with a limited number of water quality samples. In this study, NI method and regression method using the USGS ESTIMATOR model were comparatively used to calculate the pollutant loads for the Wolgokri watershed, Gangwon Province. The $NO_{3}$-N, T-N, and T-P loads using NI method and ESTIMATOR model were 13.85 kg/ha, 45.92 kg/ha, and 1.887 kg/ha, and 11.93 kg/ha,43.20 kg/ha, and 1.650 kg/ha, respectively. The estimated loads using ESTIMATOR model were lower than those using NI method by $86\%$, $94\%$, and $87\%$. These discrepancies in the estimated loads using a different load estimation method could be explained in that the total number of samples were not sufficient enough for NI method. Thus, ESTIMATOR model is recommended for the frequently stream discharge and less frequently measured water quality data.

조명부하를 고려한 BTM 태양광 발전설비용량 추정 알고리즘

배동진(Dong-Jin Bae),권보성(Bo-Sung Kwon),우수화(Su-Hwa Woo),문찬호(Chan-Ho Moon),송경빈(Kyung-Bin Song) 대한전기학회 2021 전기학회논문지 Vol.70 No.5

In the era of energy transitions, solar photovoltaic(PV) resources and wind generators are rapidly increasing. Most small-scale solar PV generators in South Korea are located behind-the-meter(BTM). It is difficult for system operators to monitor the amount of PV generations in real time. Therefore, the amount of BTM solar PV generations have caused increasing the uncertainty of load forecasting. In order to improve uncertainty of load forecasting, this paper proposes an algorithm for BTM solar PV capacity estimation considering lighting load. The capacities of BTM solar PV resources are estimated using reconstituted load based temperature filtering process and lighting load estimation. The proposed algorithm was stable for performance on BTM solar PV capacity estimation and improved the accuracy of load forecasting throughout case studies.

가상 질량 동조기에 의한 구조물의 감쇠비 추정

황재승 한국풍공학회 2016 한국풍공학회지 Vol.20 No.1

본 연구는 가상 질량 동조기(VMT)를 이용하여 구조물의 응답으로부터 구조물의 감쇠비를 구하는 기법을 다룬다. 백색잡음뿐만아니라, 특정 진동수 가진, 충격하중 가진 등 다양한 하중종류 및 특성에 의하여 발생한 구조물의 계측응답에 대하여 VMT를 적용하였을 때 구조물의 감쇠비를 추정하는 기법에 대해서 다루고, VMT의 동적특성이 구조물 감쇠비 추정에 미치는 영향을 수치적으로 분석하였다. 수치해석결과에 의하면, VMT에 의하여 구조물 감쇠비 추정이 충분한 신뢰성을 가지고 예측되는 것을 확인 할 수 있었다. 충격하중을 받는 응답을 이용하는 경우 VMT에 의하여 가장 안정적으로 구조물 감쇠비 추정이 가능한 것을 알 수 있었으며, 백색잡음, 협소대역 하중에 대해서도 VMT의 지정 감쇠비를 너무 작게 산정하지 않으면 감쇠비 추정이 가능한 것으로 나타났다. 정현파의 경우에는 가진 진동수의 VMT 비율을 이용하여 감쇠비 추정이 가능한데 고유진동수와 인접할수록 정밀도가 높아지는 것을 알 수 있었다. This study outlines a technique to obtain a structural damping ratio from measured responses of the structure using the virtual mass tuner(VMT). For the structural responses induced by the different load types such as white noise, narrow band load, impact load and sine wave load, numerical analyses are performed to verify the applicability of VMT in the estimation of the damping ratio, and to consider the effect of the characteristics of loads and VMT on the accuracy of the damping ratio. From the numerical results, it is found that VMT is able to precisely estimate the damping ratio with a sufficient reliability regardless of the load type. When using a response by the impact load, the damping ratio is much more stably estimated. In addition, if the damping ratio of VMT is designated not too small, the damping ratio can be accurately estimated for the response induced by the white noise and narrow band load. In the case of the sine wave, it is possible to estimate the structural damping ratio using a variance ratio of the VMT at the different excitation frequencies.

Load-cell Sensor를 이용한 산지 토사유출량 계측의 현장 적용성 검토

서준표(Jun-Pyo Seo),이기환(Ki-Hwan Lee),김종엽(Dong-Yeob Kim),우충식(Choong-Shik Woo),이창우(Chang-Woo Lee),이헌호(Heon-Ho Lee) 한국산학기술학회 2018 한국산학기술학회논문지 Vol.19 No.1

최근 기후변화로 인한 집중호우, 태풍 등의 영향으로 산사태가 빈번히 발생하고 있다. 산사태를 예방할 수 있는 효율적인 방법은 사방사업이다. 이러한 사방사업의 효율성을 높이기 위해서는 산지에서 유출되는 토사량에 대한 정량적 측정이 필요하다. 본 연구에서는 산지계류에 Load-cell 센서를 설치하고, 분동테스트를 통하여 계류에서의 적용성과 재하 형태에 따른 출력값을 비교하였다. 개별 및 복합 하중시험을 실시한 결과, Site 1에서 평균 0.4kgf, Site 2에서 평균 0.6kgf 차이로 재하 형태의 영향은 낮게 나타났다. 또한 측정값의 정확도를 높이기 위해 하중계수를 산정하였다. 하중계수를 Load-cell 측정값에 적용하여 보정한 결과, 두 사이트에서 출력율이 각각 14.8%p, 24.6%p 상승하여 기준값에 근사하게 산정되었다. Load-cell 센서는 수위, 강우 등과 함께 시계열 분석을 통하여 산지 토사유출량을 정량적으로 산정할 수 있었다. 모니터링이 장기간 이루어진다면 산림유역에 대한 토사유출 매커니즘 구명에도 활용할 수 있을 것이다. 또한 Load-cell과 같은 센서를 산지 계곡에 적용함으로써 계측센서 등 관련분야 산업 발전에 기여할 수 있을 것으로 기대된다. Landslides occur frequently due to the effects of heavy rainfall and typhoons caused by climate change. Erosion control measures are needed to effectively prevent landslide damage. In order to improve their efficiency, it is necessary to quantitatively measure the sediment discharge from the mountain stream. In this study, a load cell sensor was installed in a mountain stream and the measured values were compared according to the applicability and load test type in the mountain stream. The result of the load test showed that the effect of the loading type (load test 1, 2) was low at average (loadings) of 0.4kgf and 0.6kgf at sites 1 and 2, respectively. The load factor was also derived by regression analysis to increase the accuracy of the measured values. According to the results of the load factor (normalized) to the load-cell measurement value, the output value increased by 14.8% and 24.6% in sites 1 and 2, respectively, and was calculated to be similar to the reference value. The load cell sensor enabled us to quantitatively estimate the amount of sediment discharge in the mountain stream through time series analysis with the water level and rainfall information. If the monitoring is carried out for a long time, it can be used to find the sediment discharge mechanism for the mountain stream. In addition, applying sensors such as load-cells to a mountain stream is expected to contribute to the development of related industries, such as the manufacturing of measurement sensors.

월곡리 유역의 비점원오염부하 산정을 위한 LOADEST 모델의 적용성 평가

신민환 ( Shin Min Hwan ),원철희 ( Won Chul Hee ),최용훈 ( Choi Young Hun ),김기철 ( Kim Ki Chul ),서지연 ( Seo Ji Yeon ),임경재 ( Lim Kyoung Jae ),최중대 ( Choi Joong Dae ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

In many studies, the Numeric Integration(NI) method has been used to calculate the pollutant loads because of its easy to apply. Thus, there have been needed for more accurate pollutant load estimation with a restricted number of water quality samples. And the ESTIMATOR model method has been used to calculate the pollutant loads. However, it requires the user to define the model based on a set of predefined explanatory variables. While similar to the LOADEST model, it is somewhat less flexible. The LOADEST model allows the user to choose between selecting the general form of the regression from among several predefined models and letting the software automatically choose the best model. In this study, stream flow and pollutant loads were analyzed, NI method, ESTIMATOR model method and LOADEST model method were comparatively used to calculate the pollutant loads in the Wolgok-ri watershed, Gangwon Province. Annual loads of T-N and T-P by LOADEST model were 0.49 times and 0.36 times of those by NI method, respectively. And annual loads of T-N and T-P by LOADEST model were 1.45 times and 2.3 times of those by ESTIMATOR model, respectively.

Characteristics of Pollutant Loads and Water Quality in Kwangyang Bay, Korea

Lee Dae-In,Park Chung-Kil,Cho Hyeon-Seo The Korean Society of Fisheries and Aquatic Scienc 2003 Fisheries and Aquatic Sciences Vol.6 No.3

The characteristics of pollutant loads from the various sources and seawater quality in Kwangyang Bay were evaluated. Total flow rate was estimated to be $10,868,066.8 m^3/day$ with a flow rate of R2l (the Seomjin River) as the highest one. Total COD, TN and TP loads of the input rivers and the ditches were about 27,591.8, 25,029.6 and 586.4 kg/day, respectively. Wastewater discharging loads was the greatest contributors to pollutant loads in the inner part of Kwangyang Bay. COD values in the inner part of the bay was over 3.0 mg/L, which exceeded the seawater quality criteria III of Korea. The average values of DIN and DIP were 8.62 ${\mu}gN/L\;and\;1.26\;{\mu}gP/L$, respectively. The limiting factor for algal growth was DIN. In he total discharging loads of the watershed from unit loading estimations, BOD, TN and TP were 9,132.3, 2,727.2 and 304.2 kg/day, respectively. In addition, municipal sewage by the population as pollution sources and the city of Kwangyang as administrative district had the highest loads. For a appropriate water quality recovery of Kwangyang Bay, it is suggested that it is essential to estimate reduction rate of total pollutant loads by water quality modeling.

동적 모사를 이용한 에탄 분리탑의 플레어 용량 예측에 관한 연구

박경태 ( Kyung Tae Park ),원왕연 ( Wang Yun Won ),신동일 ( Dong Il Shin ) 한국화학공학회 2014 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.52 No.5

A flare system is a very important system that crucially affects on the process safety in chemical plants. If aflare system is designed too small, it cannot prevent catastrophic accidents of a chemical plant. On the other hand, if a flaresystem is designed too large, it will waste resources. Therefore, reasonable relief load estimation has been a crucial issue inthe industry. American Petroleum Institute (API) suggests basic guidelines for relief load estimation, and a lot of engineeringcompanies have developed their own relief load estimation methods that use an unbalanced heat and material method. However, these methods have to involve lots of conservative assumptions that lead to an overestimation of relief loads. Inthis study, the new design procedure for a flare system based on dynamic simulation was proposed in order to avoid theoverestimation of relief loads. The relief load of a deethanizer process was tested to verify the performance of the proposeddesign procedure.

Study of Peak Load Demand Estimation Methodology by Pearson Correlation Analysis with Macro-economic Indices and Power Generation Considering Power Supply Interruption

Jiyoung Song,Jaegul Lee,Taekyun Kim,Yongbeum Yoon 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.4

Since the late 2000s, there has been growing preparation in South Korea for a sudden reunification of South and North Korea. Particularly in the power industry field, thorough preparations for the construction of a power infrastructure after reunification are necessary. The first step is to estimate the peak load demand. In this paper, we suggest a new peak demand estimation methodology by integrating existing correlation analysis methods between economic indicators and power generation quantities with a power supply interruption model in consideration of power consumption patterns. Through this, the potential peak demand and actual peak demand of the Nation, which experiences power supply interruption can be estimated. For case studies on North Korea after reunification, the potential peak demand in 2015 was estimated at 5,189 MW, while the actual peak demand within the same year was recorded as 2,461 MW. The estimated potential peak demand can be utilized as an important factor when planning the construction of power system facilities in preparation for reunification.

Parameter Estimation of Dynamic Load Model in Power System by using Measured Data

Tomoda, Michiya,Matsuki, Junya,Hayashi, Yasuhiro The Korean Institute of Electrical Engineers 2011 The Journal of International Council on Electrical Vol.1 No.2

In this paper, we propose a dynamic load model considering change of flux inside induction motor for transient stability analysis and we present a new method for estimating unknown parameters of the dynamic load model. The model is a parallel composite of a constant impedance load and an induction motor load behind a series constant reactance. An adequate dynamic load model is essential for evaluating power system stability and this model can represent the behavior of actual load by using appropriate parameters. However, the problem of this model has a large amount of parameters and it is not easy to estimate a lot of unknown parameters. Therefore we propose an estimating method based on Particle Swarm Optimization (PSO), which is a non-linear optimization method, by using measured instantaneous voltage sag data. We estimated parameters of the actual load by PSO to minimize error between calculated and measured power of load after a load drop due to voltage sag by the accident. It was confirmed that the proposed method was successful and PSO is effective in parameter estimation.