• Title/Summary/Keyword: flow duration analysis

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A Study on the Expression of Bergsonian Duration in Steven Holl's Stretto House (스티븐 홀의 스트레토 하우스에서 베르그송의 지속의 표현에 관한 연구)

  • Kim, Young-Hee
    • Korean Institute of Interior Design Journal
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    • v.19 no.1
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    • pp.85-93
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    • 2010
  • This study aimed to show the possibility of approaching Steven Holl's Stretto House as a vital space identical to the flow of our consciousness through Bergson's philosophy of life by understanding the expression of Bergsonian duration in the house. For the Purpose of this study, Bergson's concept of aesthetic duration was considered and duration in the Stretto House design process was analyzed, Based on the study's findings, duration according to Bergson's expression of reality in the Stretto House was further analyzed. The results of the analysis of duration in the Stretto House design process showed that duration is expressed as phenomenological time through the continuity and movement of the perceptual phenomena of space, sound, light and material that reflected Merleau-Ponty's anchoring and Bartok's Music for Strings, Percussion and Celesta. The results of the analysis of duration as an expression of reality in the Stretto House showed that duration is expressed as real time, as reality's continuous and diverse movement of vital duration, through the image and rhythm based on the intuitive recollection of the real self, sound, light and pond. Consequently, it was shown that the Stretto House could be understood as a vital space in which a vital movement of duration identical with the flow of our consciousness is expressed through the expression of reality in Bergson's philosophy of life. This study is meaningful as a foundational study of the experiential space of phenomena through Bergson's philosophy of life.

Water quality forecasting on upstream of chungju lake by flow duration (충주호 상류지역의 유황별 장래수질예측)

  • 이원호;한양수;연인성;조용진
    • Journal of environmental and Sanitary engineering
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    • v.17 no.4
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    • pp.1-9
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    • 2002
  • In order to define about concern with discharge and water-quality, it is calculated drought flow, low flow, normal flow and wet flow in Chungju watershed from flow duration analysis. Water quality modeling study is performed for forecasting at upstream of Chungju lake. It is devided method of modeling into before and after the equipment of environmental treatment institution. And it is estimated the change of water quality. Before the equipment of environmental treatment, BOD concentration is increased from 23000 to 2006 years at all site and decrease on 2012 years. The rate of increasing BOD concentration is showed height between 2000 years and 2003 years most of all site. And after the equipment of environmental treatment, it is showed first grade of BOD water quality in most of sample site beside Jucheon river. The result of water quality modeling using drought flow showed that a lot of pollution occurred. And water quality using wet flow is good, so much discharge make more improve water quality than little discharge.

Dam Failure and Unsteady Flow Analysis through Yeoncheon Dam Case(II) - Unsteady Flow Analysis of Downstream by Failure Scenarios - (연천댐 사례를 통한 댐 파괴 부정류해석 및 하류 영향 검토(II) -시나리오에 따른 댐 하류 부정류 해석 및 범랑특성 연구-)

  • Jang, Suk-Hwan
    • Journal of Environmental Science International
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    • v.17 no.11
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    • pp.1295-1305
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    • 2008
  • This study aims at the analyze of unsteady downstream flow due to dam failure along dam failure scenario and applied to Yeoncheon Dam which was collapsed August 1st 1999, using HEC-RAS simulation model. The boundary conditions of this unsteady flow simulation are that dam failure arrival time could be at 02:45 a.m. August 1st 1999 and failure duration time could be also 30 minutes. Downstream 19.5 km from dam site was simulated for unsteady flow analysis in terms of dam failure and non-failure cases. For the parameter calibration, observed data of Jeonkok station were used and roughness coefficient was applied to simulation model. The result of the peak discharge difference was 2,696 to $1,745\;m^3/sec$ along the downstream between dam failure and non-failure and also peak elevation of water level showed meanly 0.6m difference. Those results of these studies show that dam failure scenarios for the unknown failure time and duration were rational because most results were coincident with observed records. And also those results and procedure could suggest how and when dam failure occurs and downstream unsteady flow analyzes.

Flow and Combustion Characteristics according Control Strategy of Variable Valve Duration System for Compression Ignition Engine (압축착화기관용 가변밸브 듀레이션(VVD)시스템의 제어전략에 따른 유동 및 연소성능 해석)

  • Cho, Insu;Kim, Wootaek;Lee, Jinwook
    • Journal of ILASS-Korea
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    • v.25 no.2
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    • pp.45-50
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    • 2020
  • Recently, global warming and environmental pollution are becoming more important, and fuel economy is becoming important. Each automobile company is actively developing various new technologies to increase fuel efficiency. CVVD(Continuously Variable Valve Duration) system means a device that continuously changes the rotational speed of the camshaft to change the valve duration according to the state of the engine. In this paper, VVT(Variable Valve Timing) and CVVD were applied to a single-cylinder diesel engine, and the characteristics of intake and exhaust flow rate and in-cylinder pressure characteristics were analyzed by numerical analysis. In order to analyze the effect of CVVD on the actual engine operation, the study was performed by setting the valve control and injection pressure as variables in two sections of the engine operating region. As a result, In the case of applying CVVD, the positive overlap with the exhaust valve is maintained, thus it is possible to secure the flow smoothness of air and increase the volumetric efficiency by improving the flow rate. The section 2 condition showed the highest peak pressure, but the pressure rise rate was similar to that of the VVT 20 and CVCD 20 conditions up to 40 bar due to the occurrence of ignition delay.

Analysis of extreme cases of climate change impact on watershed hydrology and flow duration in Geum river basin using SWAT and STARDEX (SWAT과 STARDEX를 이용한 극한 기후변화 사상에 따른 금강유역의 수문 및 유황분석)

  • Kim, Yong Won;Lee, Ji Wan;Kim, Seong Joon
    • Journal of Korea Water Resources Association
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    • v.51 no.10
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    • pp.905-916
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    • 2018
  • The purpose of this study is to evaluate the climate change impact on watershed hydrology and flow duration in Geum River basin ($9,645.5km^2$) especially by extreme scenarios. The rainfall related extreme index, STARDEX (STAtistical and Regional dynamical Downscaling of EXtremes) was adopted to select the future extreme scenario from the 10 GCMs with RCP 8.5 scenarios by four projection periods (Historical: 1975~2005, 2020s: 2011~2040, 2050s: 2041~2070, 2080s: 2071~2100). As a result, the 5 scenarios of wet (CESM1-BGC and HadGEM2-ES), normal (MPI-ESM-MR), and dry (INM-CM4 and FGOALS-s2) were selected and applied to SWAT (Soil and Water Assessment Tool) hydrological model. The wet scenarios showed big differences comparing with the normal scenario in 2080s period. The 2080s evapotranspiration (ET) of wet scenarios varied from -3.2 to +3.1 mm, the 2080s total runoff (TR) varied from +5.5 to +128.4 mm. The dry scenarios showed big differences comparing with the normal scenario in 2020s period. The 2020s ET for dry scenarios varied from -16.8 to -13.3 mm and the TR varied from -264.0 to -132.3 mm respectively. For the flow duration change, the CFR (coefficient of flow regime, Q10/Q355) was altered from +4.2 to +10.5 for 2080s wet scenarios and from +1.7 to +2.6 for 2020s dry scenarios. As a result of the flow duration analysis according to the change of the hydrological factors of the Geum River basin applying the extreme climate change scenario, INM-CM4 showed suitable scenario to show extreme dry condition and FGOALS-s2 showed suitable scenario for the analysis of the drought condition with large flow duration variability. HadGEM2-ES was evaluated as a scenario that can be used for maximum flow analysis because the flow duration variability was small and CESM1-BGC was evaluated as a scenario that can be applied to the case of extreme flood analysis with large flow duration variability.

Analysis of Load Duration Curve Difference using 8 Day and Extended Daily Flow (8일 유량 및 일유량 자료를 이용한 오염부하지속곡선의 변화 분석)

  • Kwon, Pilju;Ryu, Jichul;Kim, Hongtae;Lim, Kyoung Jae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.166-166
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    • 2017
  • 현재 우리나라에서 많은 연구에 활용되고 있는 오염부하지속곡선(Load duration curve, LDC)은 단일 기준유량의 문제점을 개선하기 위해 전체 유량 범위를 고려한 수질오염총량관리제(Total Maximum Daily Loads, TMDL) 평가 기법으로 개발되었다(Choi et al., 2012). LDC를 이용해 목표수질 달성여부를 분석하기 위해서는 일유량자료를 바탕으로 유량지속곡선(Flow Duration Curve, FDC)의 작성이 선행되어야 하는데(Park and Oh, 2012), 365일 연속적으로 측정된 실측 자료를 이용하는 것이 가장 확실하고 정확한 방법이다. 그러나 현재 환경부에서는 총량관리 단위유역에서 8일 간격으로 실측 유량 및 수질 측정이 이루어지고 있고, 특히 주로 비강우 시에 측정이 이루어지고 있는 실정이기 때문에 고유량에 대한 모니터링 자료가 부족한 실정이다. 이 같은 이유로 많은 연구에서 불연속적인 평균 8일 간격 유량을 그대로 사용하거나 일유량자료를 확보하기 위해 다양한 방법을 이용하고 있다. 그러나 이러한 유량자료의 변동은 유랑지속곡선에 변화를 주고 결과적으로는 LDC를 이용한 목표수질 달성여부를 판단함에 있어 불확실성이 있다. 이에 본 연구의 목적은 환경부 총량측정망 8일유량자료와 이와 연계성이 있는 국토교통부 하천유량 측정망 일유량자료를 이용하여 각각의 LDC를 작성하고, 이러한 일유량과 8일유량 사용이 LDC를 이용하여 목표수질에 대한 오염부하 특성분석에 어떠한 영향을 미치는지 유량 조건별로 차이를 비교분석하는 데 있다.

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Output Characteristic Analysis of Small Hydropower Plant (소수력발전소의 출력특성 분석)

  • Park Wan-Soon;Lee Chul-Hyung
    • New & Renewable Energy
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    • v.2 no.2 s.6
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    • pp.81-85
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    • 2006
  • The output performance characteristics for surveyed sites were analyzed, using developed model. It consists of two main parts, the deciding flow duration characteristic of river and performance prediction model to estimate the output characteristics of small hydropower plants. As a result, It was found that the flowrate concerning with 25% of time ratio on flow duration curve can be selected to design flowrate of small hydropower plants, and the output characteristics of small hydropower plants having overflow dam are different from large scale hydropower plants.

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Output Characteristic Analysis of Small Hydropower Plant (소수력발전소의 출력특성 분석)

  • Park, Wan-Soon;Lee, Chul-Hyung
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.491-494
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    • 2006
  • The output performance characteristics for surveyed sites were analyzed, using developed model. It consists of two main parts, the deciding flow duration characteristic of river and performance prediction model to estimate the output characteristics of small hydropower plants. As a result, it was found that the flowrate concerning with 25% of time ratio on flow duration curve can be selected to design flowrate of small hydropower plants, and the output characteristics of small hydropower plants having overflow dam are different from large scale hydropower plants.

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Analysis of Water bady Damage at Osu Stream Using the Flow-Loading Equation and 8-Day Intervals Cumulative Flow Duration Curve (유량-부하량 관계식과 8일 간격 누적유량지속곡선을 이용한 오수천의 수체 손상도 분석)

  • Lee, Young Sung;Kim, Young Suk;Han, Sung Wook;Seo, kwon ok;Lim, chang bok;Lee, Yeong Jae;Kim, Kyunghyun;Jung, Kang-Young
    • Journal of Environmental Science International
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    • v.27 no.12
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    • pp.1179-1193
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    • 2018
  • The purpose of this study at water quality pollutants to propose proper management method for the Osu-A unit watershed which is the influent tributary located upstream of the Sumjin -river among the 13 unit watersheds in the Sumjin-river water system. Analyzed the correlation between flow-pollution loading and the correlation between land use type, BOD and TP items, and analyzed 8-day intervals Cumulative Flow Duration Curve (CFDC) and Load Duration Curve (LDC) to evaluate water quality damage. As a result, both BOD and TP were larger than 1 and the concentration of water pollutants increased with increasing flow. BOD was positively correlated with Urban and Field, and TP was positively correlated with Field with 0.710. As a result of the LDC, BOD was analyzed that the target water quality was achieved with the excess rate of less than 50%, and TP exceeded the target water quality by 50.1%. BOD usually exceeded the standard value (exceedance probability 50%) at low flow zone and On the other hand, TP usually exceeded the standard value at high flow zone. Monthly BOD (April to June) and TP (May to August) exceeded the standard. Sewage Wastewater treatment and non-point pollution control is Osu-A unit watersheds are effective in improving BOD and TP.

A study on water quality change by land use change using HSPF

  • Kim, Tae Geun;Choi, Kyoung-sik
    • Environmental Engineering Research
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    • v.25 no.1
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    • pp.123-128
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    • 2020
  • Non-point source pollutant load reductions were calculated using the Hydrologic Simulation Program-Fortran (HSPF) model under the assumption that landuse pattern was changed according to land purchases. Upon the simulation of non-point pollutant and areas with high land purchase ratios to select a buffer zone, the Namgang dam Reach 11, Imha dam Reach 10, and the Reach 136 watershed of the main river were found to rank high for the construction of buffer zones. Assuming that the forms of the purchased lands were changed to wetlands, biological oxygen demand (BOD) loads were changed through the HSPF model. No changes of BOD were present in the Namgang dam and the Imha dam watersheds. BOD loads in Reach 136 according to landuse change were analyzed through a flow duration analysis based on the total maximum daily loads of the United States. The flow duration analyses undertaken to examine changes in BOD of main river Reach 136 watershed indicated a shift of 0.64 kg/d from 3.16 to 2.52 during high flow. The change of BOD under the conditions of moist, mid-range and dry were 11.9%, 9% and 4.5%. At the low flow condition, the variation range in the BOD load was from 0.58 kg/d to 0.41 kg/d.