• Title/Summary/Keyword: 56 study stations

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Estimating Reference Crop Evapotranspiration Using Artificial Neural Network and Temperature-based Climatic Data (인공신경망모형을 이용한 기온기반 기준증발산량 산정)

  • Lee, Sung-Hack;Kim, Maga;Choi, Jin-Yong;Bang, Jehong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.61 no.1
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    • pp.95-105
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    • 2019
  • Evapotranpiration (ET) is one of the important factor in Hydrological cycle and irrigation planning. In this study, temperature-based artificial neural network (ANN) model for daily reference crop ET estimation was developed and compared with reference crop evapotranpiration ($ET_0$) from FAO-56 Penman-Monteith method (FAO-56 PM) and parameter regionalized Hargreaves method. The ANN model was trained and tested for 10 weather stations (5 inland stations and 5 costal stations) and two input climate factors, maximum temperature ($T_{max}$), minimum temperature ($T_{min}$), and extraterrestrial radiation (RA) were used for training and validation of temperature-based ANN model. Monthly reference ET by the ANN model also compared with parameter regionalized Hargreaves method for ANN model applicability evaluation. The ANN model evapotranspiration demonstrated more accordance to FAO-56 PM evapotranspiration than the $ET_0$ from parameter regionalized Hargreaves method(R-Hargreaves). The results of this study proposed that daily reference crop ET estimated by the ANN model could be used in the condition of no sufficient climate data.

Sensitivity analysis of the FAO Penman-Monteith reference evapotranspiration model (FAO Penman-Monteith 기준증발산식 민감도 분석)

  • Rim, Chang-Soo
    • Journal of Korea Water Resources Association
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    • v.56 no.4
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    • pp.285-299
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    • 2023
  • Estimating the evapotranspiration is very important factor for effective water resources management, and FAO Penman-Monteith (FAO P-M) model has been applied for reference evapotranspiration estimation by many researchers. However, because various input data are required for the application of FAO P-M model, understanding the effect of each input data on FAO P-M model is necessary. Therefore, in this study, for 56 study stations located in South Korea, the effects of 8 meteorological factors (maximum and minimum temperature, wind speed, relative humidity, solar radiation, vapor pressure deficit, net radiation, ground heat flux), energy and aerodynamic terms of FAO P-M model, and elevation on FAO P-M reference evapotranspiration (RET) estimation were analyzed. The relative sensitivity analysis was performed to determine how 10% increment of each specific independent variable affects a reference evapotranspiration under given set of condition that other independent variables are unchanged. Furthermore, to select the 5 representative stations and perform the monthly relative sensitivity analysis for those stations, 56 study stations were classified into 5 clusters using cluster analysis. The study results showed that net radiation was turned out to be the most sensitive factor in 8 meteorological factors for 56 study stations. The next most sensitive factor was relative humidity, solar radiation, maximum temperature, vapor pressure deficit and wind speed, followed by minimum temperature in order. Ground heat flux was the least sensitive factor. In case of ground surface condition, elevation showed very low positive relative sensitivity. Relativity sensitivities of energy and aerodynamic terms of FAO P-M model were 0.707 for energy term and 0.293 for aerodynamic term respectively, indicating that energy term was more contributable than aerodynamic term for reference evapotranspiration. The monthly relative sensitivities of meteorological factors showed the seasonal effects, and also the relative sensitivity of elevation showed different pattern each other among study stations. Therefore, for the application of FAO P-M model, the seasonal and regional sensitivity differences of each input variable should be considered.

Analysis of the Spatial Distribution of Pan Evaporation Trends (Pan 증발량 추세분포 분석)

  • Rim, Chang-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.3B
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    • pp.243-255
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    • 2010
  • The spatial distribution of pan evaporation and pan evaporation trends have been studied. In this study, pan evaporation data from 1973 to 1990 for 56 climatological stations were analyzed. In addition to annual average daily pan evaporation, monthly average daily pan evaporation in April, July, October and January were analyzed, considering seasonal effect. The study results indicate that in case of annual average daily pan evaporation, 38 stations out of 56 stations show decreasing trend. In case of average daily pan evaporation in January, 33 stations show decreasing trend. In April, 38 stations show increasing trend. In July, 47 stations show decreasing trend. In October, 35 stations show increasing trend. Therefore, on the whole, pan evaporation tended to decrease in January, July, and annual basis. On the other hand, pan evaporation tended to increase in April and October. Furthermore, pan evaporation trend in each individual region shows also different trend even though the region is located nearby, indicating that there are geographical and topographical effects on pan evaporation trend. Pan evaporation data and climatic data from 1973 to 2006 for 11 climatological stations were used for trend analysis. Climatic variables such as temperature, relative humidity and wind speed show same or opposite trend direction compared with pan evaporation in annual or monthly basis. Annual and monthly solar radiation trends show the same direction compared with pan evaporation; however, annual and monthly precipitation trends show the opposite direction compared with pan evaporation.

A Study about the Deposit Stations in Japanese Colonial Era (일제강점기 순회문고에 관한 연구)

  • Cho, Yong Wan
    • Journal of the Korean Society for Library and Information Science
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    • v.56 no.1
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    • pp.119-150
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    • 2022
  • This study attempted to analyze the deposit stations in Japanese Colonial Era of Korea. To do this, this study reviewed the related literature such as articles, records, statistics, books and reports selected from databases, archives and libraries. The deposit stations were categorized by the colonial governmental bodies that included the central and local governments, by the non-governmental bodies that included the quasi-public organizations, the anti-Japanese organizations and the others and religious organizations and by the public libraries. These deposit stations were analyzed according to the time and purpose of establishment, the audience and area of the services, the ways of the services and the theme and quantities of the collections. Finally, the study could find that the deposit stations were widely adopted to supplement the lack of a library infrastructure by various administrative bodies and non-governmental bodies in Japanese Colonial Era of Korea.

Evaluation of the Geum River by Multivariate Analysis: Principal Component Analysis and Factor Analysis (다변량분석법을 이용한 금강 유역의 수질오염특성 연구)

  • Kim, Mi-Ah;Lee, Jae-kwan;Zoh, Kyung-Duk
    • Journal of Korean Society on Water Environment
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    • v.23 no.1
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    • pp.161-168
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    • 2007
  • The main aim of this work is focus on the Geum river water quality evaluation of pollution data obtained by monitoring measurement during the period 2001-2005. The complex data matrix 19 (entire monitoring stations)*13 (parameters), 60 (month)*13 (parameters) and 20 (season)*13 (parameters) were treated with different multivariate techniques such as factor analysis/principal component analysis (FA/PCA). FA/PCA identified two factor (19*13) classified pollutant Loading factor (BOD, COD, pH, Cond, T-N, T-P, $NH_3$-N, $NO_3$-N, $PO_4$-P, Chl-a), seasonal factor (water temp, SS) and three Factor (60*13, 20*13) classified pollutant Loading factor (BOD, COD, Cond, T-N, T-P, $NH_3$-N, $NO_3$-N, $PO_4$-P), seasonal factor (water temp, SS) and metabolic factor (Chl-a, pH). Loadings of pollutant factor is potent influence main factor in the Geum river which is explained by loadings of pollutant factor at whole sampling stations (71.16%), month (52.75%) and season (56.57%) of main water quality stations. Result of this study is that pollutant loading factor is affected at Gongju 1, 2, Buyeo 1, 2, Gangkyeong, Yeongi stations by entire stations and entire month (Gongju 1, Cheongwon stations), April, May, July and August (buyeo 1) by month. Also the pollutant Loading factor is season gives an influence in winter (Gongju 1, buyeo 1) from main sampling stations, but Cheongwon characteristic is non-seasonal influenced. This study presents necessity and usefulness of multivariate statistic techniques for evaluation and interpretation of large complex data set with a view to get better information data effective management of water sources.

Field Technique of Non-Educated Constructors in Timber Structure of Korean-Style Secondary Station(Gong-So) -Focused on the Sin-Sung and Su-Bun Secondary Stations- (한옥 공소의 목구조 방식에 나타난 민간 기술자의 현장기법 -천주교 신성공소와 장수천주교회 수분공소를 중심으로-)

  • Park, Kwang-Hyun;Kim, Tai-Young
    • Journal of the Korean Institute of Rural Architecture
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    • v.12 no.1
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    • pp.49-56
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    • 2010
  • This paper is aimed to clarify field technique of non-educated constructors in timber structure of korean-style secondary station(Gong-So) on the annex of catholic church. The main object of this study is Sin-Sung and Su-Bun secondary stations which post-lintel structure was 2high columns(Go-Ju) 5beams(Ryang) in Jeon-Buk area of Korea. We reached the following conclusion. Firstly, these secondary stations are required a lots of space for number of persons with the introduction of basilica plane. These plans have different intervals in the layout. Secondly, they constructed the holy space by using high columns(Nae-Jin-Go-Ju). The former problems of plan layout are sloved by reinforcement and replacement eaves and rafter of logitudinal. Thirdly, the elements showed the natural feature such as irregular wooden floor, arch-type head pentrating tie and a ceiling. In the end, we knew that non-educated constructor had found a way in the problem for accepting unreasonable work.

Development of Hydroclimate Drought Index (HCDI) and Evaluation of Drought Prediction in South Korea (수문기상가뭄지수 (HCDI) 개발 및 가뭄 예측 효율성 평가)

  • Ryu, JaeHyun;Kim, JungJin;Lee, KyungDo
    • Journal of The Korean Society of Agricultural Engineers
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    • v.61 no.1
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    • pp.31-44
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    • 2019
  • The main objective of this research is to develop a hydroclimate drought index (HCDI) using the gridded climate data inputs in a Variable Infiltration Capacity (VIC) modeling platform. Typical drought indices, including, Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), and Self-calibrated Palmer Drought Severity Index (SC-PDSI) in South Korea are also used and compared. Inverse Distance Weighting (IDW) method is applied to create the gridded climate data from 56 ground weather stations using topographic information between weather stations and the respective grid cell ($12km{\times}12km$). R statistical software packages are used to visualize HCDI in Google Earth. Skill score (SS) are computed to evaluate the drought predictability based on water information derived from the observed reservoir storage and the ground weather stations. The study indicates that the proposed HCDI with the gridded climate data input is promising in the sense that it can help us to predict potential drought extents and to mitigate its impacts in a changing climate. The longer term drought prediction (e.g., 9 and 12 month) capability, in particular, shows higher SS so that it can be used for climate-driven future droughts.

Simultaneous Adjustment of Closed Traverse Net Considered the Observed Angle and Distance (측각과 측거를 고려한 개합트래버스망의 동시조정)

  • 이계학
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.8 no.1
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    • pp.51-56
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    • 1990
  • Recently, Electronic Distance Meter(EDM) is widely used for the traverse surveying and trilateration net. In this study, the closed traverse network is precisely adjusted by simultaneous adjustment of the observed angle and distance, using the Electronic Total Stations (Set 3). And also, it is examined that each kind accidental errors appear observed angles according to the observed distance and the number of repeating angle. In addition to the result, of checking between the simultaneous adjustment, the compass rule and transit rule, simultaneous adjustment in combination of the observed angle and distance is more accurate and effective than other adjustment.

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Analysis of Multiple Network Accessibilities and Commercial Space Use in Metro Station Areas: An Empirical Case Study of Shanghai, China

  • Zhang, Lingzhu;Zhuang, Yu
    • International Journal of High-Rise Buildings
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    • v.8 no.1
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    • pp.49-56
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    • 2019
  • Against the background of the rapid development of the Shanghai Metro network, this paper attempts to establish an analytical approach to evaluate the impact of multiple transport network accessibilities on commercial space use in metro station areas. Ten well-developed metro station areas in central Shanghai are selected as samples. Commercial space floor area and visitors in these areas are collected. Using ArcGIS and Spatial Design Network Analysis, the Shanghai Metro network and road network are modeled to compute diversified transport accessibilities. Evidence from land use and commercial space floor area within a 0-to-500-meter buffer zone of stations is consistent with location and land-use theory: commercial land use is concentrated closer to stations. Correlation analysis suggests that hourly visitors to the shopping mall are mainly influenced by metro network accessibility, while retail stores and restaurants are affected by both metro and pedestrian accessibility.