• 제목/요약/키워드: Flow-Field

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Improvement of Sediment Trapping Efficiency Module in SWAT using VFSMOD-W Model (VFSMOD-W 모형을 이용한 SWAT 모형의 초생대 유사 저감 효율 모듈 개선)

  • Park, Younshik;Kim, Jonggun;Kim, Namwon;Park, Joonho;Jang, Won-Seok;Choi, Joongdae;Lim, Kyoung Jae
    • Journal of Korean Society on Water Environment
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    • v.24 no.4
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    • pp.473-479
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    • 2008
  • Environment problem has been arising in many countries. Especially, soil erosion has been deemed as one of the biggest issues because sediment causes muddy water and pollutants, such as agricultural chemicals, flow in the stream with this sediment. Many studies, regarding soil loss and non-point source pollution from watershed, has been performed while serious problem has been known. Soil loss occurred in most agricultural area by rainfall and runoff. It makes hydraulic structure unstable, causes environmental economical problems because muddy water destroys ecosystem and causes intake water deterioration. As revealing serious effects of muddy water by sediment, many researches have been doing with various methods. Hydraulic structures establishments such as soil erosion control dams and grit chamber are common. Vegetative filter strip is investigated in this study because vegetative filter strip is designed for reducing sediment from upland areas of the watershed, and it has many functions, not only sediment reduction but also runoff water quality improvement and wildlife habitat. With these positive functions of the vegetative filter strip, the study about vegetative filter strip has been increasing for reducing sediment because it is more effective than hydraulic structures from an environmental perspective. But the sediment trapping efficiency by vegetative filter strip, needs to be investigated and designed first. Therefore the model, VFSMOD-W, was used in this study as it can estimate sediment trapping efficiency of vegetative filter strip under various field, vegetation, weather condition. Sensitive factors to sediment trapping efficiency are studied with VFSMOD-W, and sediment trapping efficiency equation has been derived using two most sensitive factors. It is thought that the equation suggested in this study can be used in Soil and Water Assessment Tool (SWAT), to overcome the limit of SWAT filter strip module, which is based solely on filter strip width.

Evaluation of groundwater recharge rate for land uses at Mandae stream watershed using SWAT HRU Mapping module (SWAT HRU Mapping module을 이용한 해안면 만대천 유역의 토지이용별 지하수 함양량 평가)

  • Ryu, Jichul;Choi, Jae Wan;Kang, Hyunwoo;Kum, Donghyuk;Shin, Dong Suk;Lee, Ki Hwan;Jeong, Gyo-Cheol;Lim, Kyoung Jae
    • Journal of Korean Society on Water Environment
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    • v.28 no.5
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    • pp.743-753
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    • 2012
  • The hydrologic models, capable of simulating groundwater recharge for long-term period and effects on it of crops management in the agricultural areas, have been used to compute groundwater recharge in the agricultural fields. Among these models, the Soil and Water Assessment Tool (SWAT) has been widely used because it could interpret hydrologic conditions for the long time considering effects of weather condition, land uses, and soil. However the SWAT model couldn't represent the spatial information of Hydrologic Response Unit (HRU), the SWAT HRU mapping module was developed in 2010. With this capability, it is possible to assume and analyze spatio-temporal groundwater recharge. In this study, groundwater recharge of rate for various crops in the Mandae stream watershed was estimated using SWAT HRU Mapping module, which can simulate spato-temporal recharge rate. As a result of this study, Coefficient of determination ($R^2$) and Nash-Sutcliffe model efficiency (NSE) for flow calibration were 0.80 and 0.72, respectively, and monthly groundwater recharge of Mandae watershed in Haean-myeon was 381.24 mm/year. It was 28% of total precipitation in 2009. Groundwater recharge rate was 73.54 mm/month and 73.58 mm/month for July and August 2009, which is approximately 18 times of groundwater recharge rate for December 2009. The groundwater recharges for each month through the year were varying. The groundwater recharge was smaller in the spring and winter seasons, relatively. So, it is necessary to enforce proper management of groundwater recharge during droughty season. Also, the SWAT HRU Mapping module could show the result of groundwater recharge as a GIS map and analyze spatio-temporal groundwater recharge. So, this method, proposed in this study, would be quite useful to make groundwater management plans at agriculture-dominant watershed.

Decision Making Support System for Water Supply Facilities Planning using Geographic Information System (GIS를 이용한 상수도(上水道) 계획(計劃) 의사결정(意思決定) 지원(支援)시스템 연구(硏究))

  • Ha, Sung-Ryung;Kim, Ju-Hwan
    • Journal of Korean Society for Geospatial Information Science
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    • v.3 no.2 s.6
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    • pp.101-113
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    • 1995
  • In pipeline planning, the systematic and reasonal management of topographical and spatial data are needed in order to omprove the availibilities for data analysis and the effective combinations of spatial informations. According to that fact, DBMS (Database Management System) and DSS(Decision making Support System) have to be developed for the planning of water supply system Also, the economic selection for harmonious delivery of water to target area, since the alternatives of pre-designed pipeline are influenced by hydraulic stability and geographic characteristics. In this study, GIS technique for water supply planning and management which stores graphic features and attributes as digital data sets is considered and engineering application programs are integrated for effective planning of water supply system. Decision making support system based on analyzing technical, Social and economical aspects is developed for the extension of water supply facilities and pipeline configurations. Especially, Hydraulic, land-use and economic influences are considered as important factors for the purpose of developing the system. Hydraulic analysis program(SAPID) for pipeline flow which is already developed in Water Resources Research Institute and economic analysis program(ECOVEL) are integrated with GIS for resonable decision making. Every possible aspects in pipeline planning for water supply is reviewed and the applicabilities of developed system into the field are evaluated.

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Nutrient Balance in the Paddy Fields Watershed with a Source of River Water (하천관개지역 광역논에서의 영양물질의 물질수지)

  • Lee, Jeong Beom;Lee, Jae Yong;Li, Si Hong;Jang, Jeong Ryeol;Jang, Ik Geun;Kim, Jin Soo
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.5
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    • pp.11-19
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    • 2014
  • The objective of this research was to investigate concentration and load of nutrients such as total nitrogen (TN), nitrate nitrogen ($NO_3$-N) total phosphorous (TP), and phosphate phosphorous ($PO_4$-P) in a 23.4-ha paddy fields watershed with river water source. Water samples for irrigation water, drainage water, ponded water and groundwater were collected, and irrigation and drainage water were measured at 5~10 day intervals during normal days and at 2~6 hours intervals during three storm events. The amount of irrigation water in the study area was over 2,000 mm, which is almost identical to that in the area irrigated from a large reservoir but much more than that in the area irrigated from a pumping station. Mean flow-weighted concentrations of TN and TP in irrigation water were 2.8 and 0.15 mg/L, respectively, higher than those in the area irrigated from a large reservoir or a pumping station. The ratios of irrigation load to total inflow load for TN and TP were 88 %, and the ratios of surface outflow load to total outflow load for TN and TP were over 90 %, indicating that total nutrient load may be greatly affected by water management. The nutrient loads per area in the study area were estimated as TN 21.1 kg/ha and TP 1.1 kg/ha. Especially, the TP load per area in the study area was smaller than that in the area irrigated from a large reservoir or a pumping station. This may be because outflow load is not high likely due to sedimentation of particulate P and irrigation water load is high due to high TP concentration in irrigation water and high amount of irrigation water.

Estimation of Carrying Capacity in Kamak Bay( I ) - Estimation of Primary Productivity Using the Eco-hydrodynamic Model- (가막만의 환경용량 산정( I ) -생태계모델을 이용한 기초생산력 산정-)

  • CHO Eun Il;PARK Chung Kil;LEE Suk Mo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.3
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    • pp.369-385
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    • 1996
  • The eco-hydrodynamic model was used to estimate the primary productivity of the oyster culture grounds in Kamak Bay. It is composed of the three-dimensional hydrodynamic model for the simulation of water flow and ecosystem model for the simulation of phytoplankton. The ecosystem model was applied to simulate phytoplankton biomass during culturing period in condition of no oyster culture grounds. The field surveys were conducted from May, 1994 to March, 1995 in Kamak bay. The results showed the concentration of chlorophyll $\alpha$ to be $1.00\~23.28\;{\mu}g/l$ in the surface layer, $1.27\~29.97\;{\mu}g/l$ in the middle layer and $1.23\~23.08\;{\mu}g/l$ the bottom layer. In monthly variations of chlorophyll $\alpha$ concentration, very high concentration were found in July, 1994 and very low concentrations in December, 1994. As the results of three-dimensional hydrodynamic simulation, the computed tidal currents ave mainly toward the inner part of bay through Yeosu Harbor and the southern mouth of a bay during the flood tide. The computed residual currents were dominated southward in Yeosu Harbor and eastward in the mouth of bay and also showed strong clockwise water circulation at the mouth of bay. The pattern between the simulated and observed tidal ellipses at three stations was very similar. The mean relative errors of all levels between the simulated and observed phytoplankton biomass at 14 stations in Kamak Bay were $13.81\%,\;9.31\%\;and\;17.84\%$, respectively. The results of phytoplankton biomass simulation showed that the biomass increased from June to September and rapidly decreased to December and then slowly increased to March. Primary productivity was estimated in the range of $0.99\~10.20gC/m^2/d$ with the average value of $4.43gC/m^2/d$ in condition of no oyster culture grounds. Primary productivity was rapidly increased from lune to August and rapidly decreased to December and then slowly increased from January to March in Kamak Bay.

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Geophysical Investigation of the change of geological environment of the Nanjido Landfill due to the Stabilization Process (난지도 매립장의 안정화에 따른 지질환경 변화 조사를 위한 지구물리 탐사)

  • Lee, Kie-Hwa;Kwon, Byung-Doo;Rim, Hyoung-Rae;Yang, Jun-Mo
    • Journal of the Korean Geophysical Society
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    • v.3 no.2
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    • pp.113-126
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    • 2000
  • We have conducted multiple geophysical surveys to investigate the geoenvironmental change of the Nanjido Landfill due to the stabilization process. Geophyscial surveys are comprized of gravity, magnetic, dipole-dipole electrical and SP methods. Due to the field conditions, surveys were conducted on the top surface of the landfill no.2 and southern border areas in front of landfills. The gravity anomalies obtained on the top surface of the landfill no.2 in 1999 show that the gradient of the anomaly on the central area is decreasing in comparison with that observed four years ago. The complexity of magnetic anomaly pattern it also decreasing. These facts suggest that the stabilization work of the Nanjido landfill makes some progress by compaction process due to repetitive subsidence and refilling. The dipole-dipole electrical resistivity and SP data obtained on the outside of the waterproof wall at the landfill no.1 were severely affected by unsatisfactory surface conditions. On the other hand, the dipole-dipole electrical resistivity profiles obtained on the inside and outside parts of the waterproof wall at the landfill no.2 show the blocking effect of leachate flow by the waterproof wall. Few SP anomalies are observed on the top and side surfaces of the landfill no.2, but SP anomalies obtained on the base area inside the waterproof wall strongly reflect the effect of leachate collecting wells.

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A Study of Expressway Tollbooth Metering Effect (고속도로 영업소 미터링 효과에 관한 연구)

  • Im, Jin-Won;Yoon, Jae-Yong;Lee, Eui-Eun;Kim, Kwan-Min
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.4
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    • pp.1-10
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    • 2011
  • According to the worldwide efforts to reduce greenhouse gases consequent upon climatic change, the field of road traffic is also making diverse efforts to reduce the emissions of greenhouse gases. Among these, the exhaust gases from vehicles, the so-called main culprit of the greenhouse gases will take place the more as delay and tie-up of vehicles ever take place. Accordingly, as a scheme for reducing the delay & tie-up of vehicles, it's possible to bring up the idea of supply of new facilities and management of the existing facilities; recently, a lot more focus is being put on the management of the existing facilities due to enormous amounts of construction cost. In the midst of growing concern for traffic demand management policy, it's about the time we should do research on the tollbooth metering on the expressway whose research is almost non-existent home and abroad. As a traffic demand management policy coming to happen in case of the management of pay expressway like Japan and Korea, this research analyzed the contents of tollbooth metering, its effect and its subsequent convenience. Especially as a tool for effect analysis, this research made an analysis using VISSIM-a micro-simulation tool. As the tollbooth metering promoted, as a part of green traffic promotion strategy, is expected to contribute to improvement in traffic flow and reduction in carbon emissions, etc. It seems that there needs to be continuous research work on the management plan & revitalization plan for maximization of its effect later as well.

The clinical study on 2 cases of Patients of Idiopathic Blepharoptosis (특발성(特發性) 안검하수(眼瞼下垂) 치료(治療) 2례(例)에 대한 증례보고)

  • Jung, Young-don;Kim, Jung-ho;Song, Min-sic;Park, Young-soo;Heo, Yoon-kyoung;Kim, Young-il;Hong, Kwon-eui;Yim, Yun-kyoung;Lee, Hyun
    • Journal of Acupuncture Research
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    • v.21 no.6
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    • pp.281-289
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    • 2004
  • Objective : Blepharoptosis is drooping of eyelid which causes impairment of visual field by covering partially or completely, and it is classified into congenital ptosis and acquired one. In western medicine, idiopathic blepharoptosis is usually treated by tarsectomy. Contrary to that concept, we consider eyelid is assigned to Yookryoon(肉輪) among Ohryoon(五輪) which matches to spleen. In oriental medicine, it can be treated by promoting spleen and kidney. Here I report two cases of idiopathic blepharoptosis improved by conservative acupuncture therapy and herb medicine. Methods : The changes in clinical symptoms of general body weakness, anorexia, dizziness, dry eye, etc, in degree of eyelid drooping and in individual expression were described as they were treated with acupuncture therapy, herb medicine, Bojoong-ikgi-tang(補中益氣湯) and some physical therapy including Negative, I.C.T, S.S.P and Carbon. Results : Symptoms(ex) general body weakness, anorexia, dizziness, dry eye, etc) at admission improved and disappeared gradually with acupuncture therapy and herb medicine. The patients could discharge with favorable recovery. Conclusions : In oriental medicine, blepharoptosis is mainly treated by promoting Qihyul(氣血) and enhancing flow of that. If the patient has deficiency of Suhnchun-poomboo(先天稟褓賦) and Mungmoon-hwa(命門火), he is treated by promoting Shin-yang(腎陽). If he is weak in Bee-qi(脾氣), he needs to be treated by strengthening Bee-yang(脾陽) where patient with lack of Ganhyul(肝血) is supposed to be treated by promoting Hyul(血). These following two cases were managed by acupuncture, herb medicine and physical therapy on idiopathic blepharoptosis.

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A Study on the Pozzolan Reactivity and Mechanical Characteristic of Blended Portland Cements using CFBC Fly Ash (순환유동층 플라이 애시를 사용한 혼합시멘트의 포졸란 반응성과 역학적 성질에 관한 연구)

  • Park, JongTak;Oh, Hongseob
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.6 no.3
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    • pp.207-213
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    • 2018
  • Nowadays, circulating fluidized bed combustor(CFBC) boilers system that can reduce environmental pollution particles are widely used in electric power plants. But the fly ash generated from CFBC boilers has lower $SiO_2$ and higher MgO and $SO_3$ contents and also has free CaO inducing expansion and abrupt initial setting of concrete. Therefore, revised KSL5405 for CFBC fly-ash as well as pulverized coal combustion(PCC) is introduced in the concrete field. In this study, the chemical properties and mechanical properties of blended cements with PCC and CFBC fly-ash produced in Korea are analyzed. The blended cement with only CFBC fly ash shows a lower length change than OPC but a higher flow change ratio. The compressive strength of blended cement paste with PCC and CFBC fly ash is slightly greater than that of cement paste with only PCC fly-ash. Based on the results, CFBC flyash blended cement products should be used with PCC flyash to ensure the material stability and material properties.

Nursing Knowledge/Power and Practice in Pediatric Intensive Care Unit (간호학적 지식/권력과 실무: 아동중환자실을 중심으로)

  • Lee Eun Joo;Hong Kyung Ja
    • Child Health Nursing Research
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    • v.7 no.1
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    • pp.85-95
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    • 2001
  • The purpose of this study was to reveal what influences the divergent methodological researches have brought the nursing practice in during the past 3 decades. The nursing record sheets ie, the nursing discourses were analyzed to know the knowledges that were recorded, accepted and communicated in nursing practice at pediatric intensive care units, and unclosed the philosophical and methodological position of that knowledges. The texts were 13 sheets, 3 kinds of nursing record(7 24hours flow charts, 4 nursing information record sheets and 2 transfer record sheets) used at 4 hospitals. The unit of analysis was 'word'. First, all words of the sheets were listed up, clustered into categories based on their contents. And then, the larger conceptual themes were drawn to elucidate the effect of the knowledge/power and the philosophical and methodological position of that knowledges. To enhanced the validity of the analysis, the data were analyzed by two researchers. The 'words' were classified into 3 categories; 'general information', 'assessment' and 'inter-vention'. The conceptual themes of the texts were 'the gaze for quantification and objectification' and 'technical/assimilated caring'. This themes reflected the logic positivistic and biomedical view that had dominated at clinical practice. Nursing has endeavored to resist the logic-positivistic knowledge/power and to established the nursing knowledge/power based on multiple philosophies and methodologies, especially phenomenological-interpretative. But the results of this study revealed that such efforts in nursing theory and research couldn't influenced the knowledge of practice. Logic positivism was yet so strong and the biomedical model yet dominated in the clinical practice. It identified that the borrowed theory and the knowledge from the received view gave nursing the power. But they were modalities that reinforced the dominant, medical power. Nursing has investigate the other positions (feminism, Habermas' critical social theory and Foucault's discourse theory). This positions suggest different assumptions but share the common concepts; equality, emancipation and freedom. The important point is how make these concepts the practical for nursing knowledge/power in practice. We must recognize that the praxis at clinical setting take place at the field unlike theoretical praxis. The change of clinical practice is the social, economic and political change.

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