• 한국수자원학회논문집
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• 제37권3호
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• pp.249-255
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• 2004

농업용수 회귀율을 조사하기 위하여 2003년 관개기 동안 많은 실측을 수행하였다. 본 연구지역은 경상남도 창녕군에 위치한 대암양수장 유역일원이다. 관개용수를 공급하기위하여 건설된 대암 양수장 유역 내 논에 대하여 물수지분석을 실시하였다. 본 연구지역에서의 일 강우량 자료를 수집하였으며, 또한 관개율, 배수율, 침투 및 증발산을 실측하였다. 관개량과 배수량은 기록형수위계(GTDL-L10)를 설치하여 관계기 동안 지속적으로 관측하였다 침투 및 증발산은 직경 3mm PVC 감수심계 및 직경 200mm PVC 침투계를 이용하여 측정하였다. 총관개량 및 총 지표배수량은 654.7mm와281.2mm로 나타났으며, 총 침투량과 총증발산량은 각각 36.0mm 및 160.0mm였고, 일평균 증발산량은 4.3mm/d 였다. 신속회귀율과 지연회귀율은 각각 43.0% 및 5.5%로 전체회귀율은 48.5 %로 나타났다. 따라서, 본 시험지구에서 공급된 관개용수량이 설계기준보다 훨씬 많은 양의 관개용수를 공급하고 있음을 알 수 있었다. 이는 적정한 용수관리원칙 보다는 지역주민들의 요구에 의한 과다공급으로 인한 부적적한 용수관리에 기인하는 것으로, 추후에 농업용수설계기준을 현실에 맞게 변경해야함을 의미한다.

• 한국농공학회지
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• 제35권3호
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• pp.23-35
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• 1993

The objectives of this paper were to validate the proposed network flow model using field data and to demonstrate the model applicability for various purposes. The model was tested with data from the Banweol watershed, where an intentive streamflow gauging system has been established. Model parameters were not calibrated with field data so that it can be validated as ungaged conditions. Three different schemes were employed to represent the drainage system of the tested watershed : a single, complex, and detailed network. The single network assumed the watershed as a cell, while complex and detailed networks considered several cells. The results from different schemes were individually compared satisfactorily to the observed daily stages at the Banweol reservoir located at the outlet of the watershed. The results from three schemes were in close agreement with each other, Justifying that the model performs very well for different network schemes being used. Daily streamflow from three network schemes was compared for a selected reach within the watershed. The results were very close to each other regardless of network formulation. And the model was applied to simulate daily streamflow before and after the construction of a reservoir at a reach. The differences were discussed, which reflected the influences of the dam construction upon the downstream hydrology. Similar appliocations may be possible to identify the effects of hydraulic structures on streamflow.

• 한국농공학회논문집
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• 제56권6호
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• pp.45-53
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• 2014

This study presents a system dynamics modeling approach to simulate daily streamflow in a watershed including wastewater treatment plant which contributes to irrigation water supply. The conceptual system dynamics model considering the complex and dynamic hydrological processes in the watershed was developed. The model was calibrated and validated each for two years based on observed flow data. Model performances in terms of $E_{NS}$, RSR, PBIAS, and $R^2$ were 0.64, 0.60, -3.6 %, and 0.64 for calibration period, and 0.66, 0.58, -2.6 %, and 0.66 for validation period, respectively, showing an applicability on generating the daily streamflow. System dynamics modeling approach could help better understand the hydrological behavior of the watershed being reused wastewater for agriculture, by providing graphical dynamics of the hydrological processes as well as conventional rainfall-runoff model results.

• 한국콘텐츠학회논문지
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• 제14권3호
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• pp.374-384
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• 2014

우리나라 유가증권시장의 추세 흐름과 투자자들의 투자 포지션의 관계를 중심으로 투자자들의 거래가 어떠한 특징을 갖는지를 실증적으로 분석하였다. 연구 대상 기간은 2004년 1월부터 2011년 12월까지 8년간인 총 96개월의 1,991일간이다. 분석에 사용된 자료는 한국종합주가지수(KOSPI)와 각 거래집단의 총매수량과 매도량, 매수대금과 매도대금 등이다. 매월 말과 매일 종가 두 자료를 이용하여, 각 집단 간의 상관관계를 검정하고 회귀분석을 하였다. 본 연구는 시장을 장기적인 관점에서 국면을 세분화하여 각 투자집단의 투자 포지션을 검정하였다. 외국인들과 기관들은 주로 고가 종목에 대한 거래에 집중되었다는 것을 알 수 있었다. 그리고 국면을 좀 더 세분화하여 검정한 결과 외국인 투자자들은 기관들과는 달리 상승3기에 지수가 상승할 경우 증시에서 빠져나가는 현상을 볼 수 있었다. 하락 말기에 개인들은 매도를 증가시키고 있다는 것을 알 수 있었다. 일반적으로 개인들은 시장의 흐름과 역행하면서, 외국인 투자자들의 상대방이 되어 반대 포지션을 선택하고 있다고 할 수 있을 것 같다.

• 한국물환경학회지
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• 제34권3호
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• pp.328-338
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• 2018

The objective of this study was to evaluate the applicability of a HSPF (Hydrological Simulation Program-Fortran) model for runoff estimation in the Namgang dam watershed. Spatial data, such as watershed, stream, land use, and a digital elevation map, were used as input for the HSPF model, which was calibrated and validated using observed runoff data from 2004 to 2015 for three stations (Sancheong, Shinan, Changchon) in the study watershed. Parameters for runoff calibration were selected based on the user's manual and references, and parameter calibration was done by trial and error. The $R^2$ (determination coefficient), RMSE (root-mean-square error), NSE (Nash-Sutcliffe efficiency coefficient), and RMAE (relative mean absolute error) were used to evaluate the model's performance. Calibration and validation results showed that annual mean runoff was within a ${\pm}5%$ error in Sancheong and Shinan, whereas there was a14% error in Changchon. The model performance criteria for calibration and validation showed that $R^2$ ranged from 0.80 to 0.92, RMSE was 2.33 to 2.39 mm/day, NSE was 0.71 to 0.85, and RMAE was 0.37 to 0.57 mm/day for daily runoff. Visual inspection showed that the simulated daily flow, monthly flow, and flow exceedance graph agreed well with observations for the Sancheong and Shinan stations, whereas the simulated flow was higher than observed at the Changchon station.

• 산업경영시스템학회지
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• 제43권3호
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• pp.77-86
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• 2020

In this study, to improve the logistics flow of existing given chemical logistics warehouse, four logistics flow alternatives were proposed to minimize truck interference by building simulation model. The simulation model for chemical storage warehouse was built to evaluate system performance. Among the four new improved alternatives based on the basic model, the model with the same truck's pathways and locations of facilities identified an increase in the number of interferences but a decrease in daily working hours as the number of resources in a particular facility increases. Therefore, the three groups were classified as 'efficiency', 'complementary', and 'safety' based on the daily working hours, and the ratio of trucks entering two types of logistics warehouse was set in consideration of future market fluctuations. For each of the six types, the optimal number of resources was selected as the number of resources in the facilities with the least number of interferences in the basic model and the evaluation measures and characteristics set in this study were compared and analyzed. As a result, the Alternative 4 model operating the underground roadway produced interference between 17.0% and 36.4% of the basic model, with 113.3% of the interior loadspace.

• 대한가정학회지
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• 제41권8호
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• pp.213-227
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• 2003

The purpose of this study is to explore a weekly life of Korean high school students, especially focused on their activities, locations, and flow. The data were collected from 116 high school students by the Experiential Sampling Method, employing a cellular-phone as a signaling device. Students reported, in response to the 6964 random signals, that 43.4% of their time was spent for social/leisure activities. An additional 31% percent of time was used for productive activities and the rest of times belonged to maintenance activities. When engaged in productive activities, they usually reported anxiety, while they felt bored for social/leisure activities and flow for maintenance activities. The most pervasive context of their lives was school (42.8％), followed by home (33.3%), public space (24.6%), and educational institutes (9.2%). In general, they experienced flow for the most of the locations, except educational settings in which they felt anxiety. The flow for productive activities varied by gender, pending on where they had productive activities, while others did not show any significant differences in the activity flow by locations.

• 해양환경안전학회지
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• 제25권5호
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• pp.589-600
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• 2019

한국 남해안 금호열도 주변 다도해역의 조류특성과 해수순환 구조를 파악하기 위해 대조와 소조시 ADCP bottom tracking을 이용한 25시간 선박 항주관측을 실시하였다. 대조시 낙조와 창조 방향은 남동-북서이며, 최강유속은 표층 약 40 cm/s이다. 개도주변은 지형적 특성으로 주변해역의 탁월유향과 다르고, 유향 유속의 분산이 크다. 전 구간 표~저층 흐름에 두드러진 경압모드 성분은 없었다. 이는 좁은 수로와 얕은 수심, 빠른 유속으로 지형성와류나 eddy로 인한 연직혼합이 활발했음을 나타낸다. 소조시 조류는 남남동-북북서, 평균유속은 대조의 85 %이다. 탁월유향은 대조보다 우세하지 못하고 지속시간도 짧다. 흐름은 연직방향 유속시어, 수평와류, 비대칭 조류혼합으로 물질의 수평 연직이동이 왕성할 것으로 추정된다. 일평균조류는 개도 서~북서 수로해역이 북서~북동, 금오도 서쪽은 서남서~남남서 방향 최대 21 cm/s의 흐름이 존재한다. 소리도 서쪽에는 좌선환류나 와류가 형성되었다.

• Journal of Animal Science and Technology
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• 제48권4호
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• pp.487-492
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• 2006

본 연구는 우군의 일일 유량에 대한 비유형질의 특성을 분석하고자 하였으며 공시된 젖소는 농촌진흥청 축산연구소에서 사육된 착유우로서 2005년 11월부터 2006년 4월까지 1일 2회 착유를 하는 우군의 자료를 이용하였다. 시험축은 하나의 우군으로 동일한 사양조건에 의하여 관리된 종모우 66두를 가지는 착유우 154두에서 수집된 기록 12,561개를 분석하였다. 공시축의 평균유기는 139.7일, 평균산차는 1.9산, 착유당 평균유량 13kg을 나타내었다. 평균 비유속도는 최고 비유속도의 64% 수준으로 측정되었다. 비유지속시간, 최고비유속도, 평균비유속도, 착유당 평균유량에 대하여 오후 착유 보다 오전 착유가 높게 나타났고, 산차간에서는 비유지속시간을 제외하고 산차증가와 함께 증가하는 경향이었다. 비유지속시간, 최고비유속도, 평균비유속도 및 착유당 평균 유량에 대한 유전력은 각 0.49, 0.70, 0.58, 0.36으로 비교적 높게 추정되었다. 한편 비유지속시간과 비유속도간에는 부의 유전상관이, 비유지속시간과 착유당 유량간에는 정의 상관이, 최고비유속도에 대한 평균비유 속도(0.87)와 착유당 유량(0.23)은 정의 상관을 보였고, 평균비유속도와 착유당 유량간(0.30)에도 정의 유전상관을 보였다. 결론적으로 비유속도는 유량과 함께 증가하였으나 비유지속시간과는 부의 관계를 보였으나 보다 의미 있는 유전적 특성을 파악하기 위하여 더 많은 두수를 이용한 연구가 필요할 것으로 사료된다.

• 전기학회논문지
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• 제66권3호
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• pp.475-485
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• 2017

This paper develops a conversion function and method transforming from daily peak load curve used $LOLE_D$ [days/year] to hourly load curve used $LOLE_H$[hours/year]and describes relationship between $LOLE_D$ [days/year] and $LOLE_H$ [hours/year]. The indices can not only be transformed just arithmetically but also have different characteristics physically because of using their different load curves. The conversion function is formulated as variables of capacity and forced outage rate of generator, hourly load daily load factor and daily peak load yearly load factor, etc. Therefore, the conversion function (${\gamma}={\varphi}$(.)) can not be simple. In this study, therefore, the function is formulated as linear times of separated two functions. One is an exponential formed conversion function of daily load factor. Another is formulated with an exponential typed conversion function of daily peak load yearly load factor. Futhermore, this paper presents algorithm and flow chart for transforming from $LOLE_D$[days/year] to $LOLE_H$[hours/year]. The proposed conversion function is applied to sample system and actual KPS(Korea Power System) in 2015. The exponent coefficients of the conversion functions are assessed using proposed method. Finally, assessment errors using conversion function for case studies of sample system and actual system are evaluated to certify the firstly proposed method.