• Title/Summary/Keyword: RMA-2

Search Result 212, Processing Time 0.026 seconds

해외 타이어재활용 시장

  • 대한타이어공업협회
    • The tire
    • /
    • s.240
    • /
    • pp.52-57
    • /
    • 2009
  • 미국고무협회(RMA)는 1990년부터 시작하여 미국의 폐타이어 시장에 대한 보고서를 2년마다 작성하고 있다. 기존 수량 기준을 중량으로 바꾸어 현황파악을 보다 정확히 할 수 있게 한 금년 5월 보고서에 따르면, 미국의 07년 폐타이어 재활용률은 중량기준으로 89.3%를 기록하였다.

  • PDF

Effects of Operation of the Kyeongpo Retarding Basin on Flood Water Levelin Kyeongpo Lake (경포유수지 운영이 경포호의 홍수위에 미치는 영향)

  • Park, Sang Doeg;Lee, Seungkyu;Shin, Seung Sook;Yoon, Byung Man
    • Journal of Wetlands Research
    • /
    • v.18 no.4
    • /
    • pp.413-423
    • /
    • 2016
  • Effects of the design flood share of the Kyeongpo retarding basin, which has a function for flood control of the Kyeongpo river assigned to the Kyeongpo prickly water lily wetland, on the Kyeongpo lake and the downstream of Kyeongpo river were analyzed on the bassis of the hydraulic experiments and the numerical simulations using RMA-2 model. Reproducing a complex water flow system of the area of Kyeongpo lake, the unsteady flow simulations were performed. The data obtained in hydraulic experiments were used to determine parameters of the numerical model which simulated the flows for various flood scenarios in the downstream area of Kyeongpo river. With increasing the design flood share rates in the retarding basin, the water level was increased in the lake and is decreased in the river. The characteristics of flood flow interaction between Kyeongpo river and Kyeongpo lake were understood. These results may be used to management the Kyeongpo lake during flood season.

Development of Grid Reconstruction Method to Simulate Drying/Wetting in Natural Rivers (II): Model Application and Comparison (자연하천에서 마름/젖음 처리를 위한 격자재구성 기법의 개발 (II): 모형의 적용 및 비교.검토)

  • Choi, Seung-Yong;Kim, Sang-Ho;Hwang, Jae-Hong;Han, Kun-Yeun
    • Journal of Korea Water Resources Association
    • /
    • v.42 no.11
    • /
    • pp.989-1004
    • /
    • 2009
  • The objective of this study is to examine validation of Grid Reconstruction Method, which is developed to simulate drying/wetting in complex natural rivers with wetting and drying domain areas. To verify application of the developed model, the model was applied to natural rivers with wetting and drying domain areas such as Han river and Nakdong river. The simulation results have shown good agreements with observed data and the results for the developed model were more accurate and improved stability of numerical computation than those of RMA-2 model. If the analysis of contaminant advection-diffusion and sediment transport are performed with the study results, the results can be effectively applied to river flow analysis and ecological hydraulics.

Stability Analysis of Low Flow Revetments on External Forces (저수호안에 작용하는 외력에 의한 안정성분석)

  • Kim, Chul;Park, Nam-Hee;Kim, Dae-Young;Kim, Yun-Hwan
    • Journal of the Korean Society of Hazard Mitigation
    • /
    • v.8 no.5
    • /
    • pp.147-153
    • /
    • 2008
  • Tractive forces by flowing water and ship generated waves are items that affect the stability of the low flow revetments among various external forces exerting on those revetments. Bank revetment stability by these external forces is analysed in this study. The study area is the section of the test construction area changing the artificial revetments to ecological revetments in Han river. Tractive forces are computed using the calculated flow velocity using RMA-2 model. The stability is analyzed comparing the calculated tractive forces with permissible tractive forces of the revetments in the study area. The calculated tractive forces at section number 93 is higher than permissible tractive forces in that section, so the section is estimated hydraulically unstable. The calculated tractive forces for the storm of 10th August 2007 are small compared to the permissible tractive forces in all sections. The sections are considered to be hydraulically stable, but have been eroded in some parts. The reason for the erosion is considered to have insufficient time for the plants taking root, and be exerted composite forces such as forces by ship generated waves. Ship generated waves by the excursion boats and small boats called river taxi was calculated. Wave forces by these calculated waves are computed and compared with the supporting forces of the revetment material. The external forces exerted by the ships in Han River on the revetments is very little compared with the permissible supporting forces of the revetments, so the revetments are estimated hydraulically stable. But considering the composite forces are exerted simultaneously, the stability consideration should include these composite forces.

Analysis of Fish Physical Habitat Changes Due to River Improvement (하천정비에 따른 어류 물리서식처의 변화량 분석)

  • Seo, Il-Won;Park, Sung-Won;Song, Chang-Geun;Kim, Sung-Eun
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2010.05a
    • /
    • pp.551-555
    • /
    • 2010
  • 수생 생태계에서 하천 어류 서식 환경을 보호하고 유지하기 위해서는 어류의 적절한 서식 공간 확보가 선행되어야 하며, 하천정비사업에 따른 준설 시 하상변동으로 및 유속 변화로 인하여 발생하는 다양한 영향을 충분히 검토해야 한다. 본 연구에서는 우선 교각의 설치와 합류부위치로 인해 발생하는 모의 영역 내의 2차원 흐름거동을 RMA-2 모형으로 분석하였다. 또한 어류의 미시서식처를 고려한 최적의 영역에 대한 면적을 산정하였다. 이를 위해서 2차원 물리 서식처 모의 모형인 River2D를 적용하여 가중가용면적-유량 관계 곡선의 도출을 통해서 최적유량 산정시 중요한 지표인 WUA (Weighted Usable Area)의 산정결과를 어종별, 지역별 그리고 정비사업 전후에 대한 비교하였다. 적용구간은 낙동강 살리기 사업의 25공구(칠곡2, 구미 1지구: 약 8.74 km) 전체를 대상으로 하며 그중에서도 지류 합류부인 경암천부근 (제1지역)과 교각부근(제2지역)에서의 분석을 실시하였다. 피라미에 대한 WUA 값 산정결과 하천정비후에 정량적인 개선 효과를 확인하였으나 안정적인 수심 및 유속분포 지역의 개선을 위한 설계검토가 필요하다 할 수 있다.

  • PDF

Development and application of simulator for spotlight SAR image formation and quality assesment using RMA (RMA를 이용한 Spotlight SAR 영상형성 및 품질평가를 위한 시뮬레이터 개발 및 구현)

  • Kwak, Jun-Young
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.39 no.2
    • /
    • pp.183-194
    • /
    • 2011
  • Synthetic aperture radar (SAR) is widely used because of high resolution imaging capability in all weather and day/night condition. In this paper development of Spotlight SAR simulator is proposed for image quality analysis. Proposed SAR simulator is based on the SAR system design parameters so that SAR image performance can be expected which is essential throughout the full system development procedure from the initial concept design stage to the final in-flight calibration and validation stage. The raw data of ideal point target is first generated by taking account of the flight and imaging geometry and the various SAR system design parameters, and the Spotlight image formation algorithm is implemented in order to obtain the point target response. Finally the image quality of the generated raw data is analyzed in terms of spatial resolution, peak to sidelobe ratio and integrated sidelobe ratio.