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Within a wide range of best management practices for stormwater management in urban areas, there has been an increasing interest in source control measures. Source controls such as low-impact development (LID) techniques are potentially attractive as retrofit options for older developed areas that lack available land to implement conventional measures such as stormwater management ponds. Hence, distributed urban drainage models requiring detailed representation of developed drainage areas should be developed to accurately estimate the benefits that LIDs may provide. This study (1) presents a two-stage classification process on a high-resolution WorldView-2 image, and (2) demonstrates how to use the extracted land cover information in the subsequent hydrologic modelling and assessment of different LIDs’ performance. The proposed two-stage classification method achieved an overall accuracy of 80.6%, whereas a traditional pixel-based achieved 68.4% in classifying the same urban area into six land cover classes. From the classification results, the hydrologic properties of micro-subcatchments were imported in the United States Environmental Protection Agency Storm Water Management Model to assess the performance of LIDs. A reduction of run-off volume 18.2% and 37.1% was found with the implementation of porous pavement and bioretention, respectively, in a typical low-rise residential area located in the city of San Clemente, California, US. The study demonstrates the use of high-resolution remote sensing image to aid in evaluating LID retrofit options, and thus benefits in situations where detailed drainage area information is not available. 相似文献
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Abdel-Fattah Attia H. A. Ismail I. M. Selim A. M. Osman I. A. Isaa M. A. Marie A. A. Shaker 《中国天文和天体物理学报》2005,5(4):347-355
We present a new method for determining the age and relative contribution of different stellar populations in galaxies based on the genetic algorithm. We apply this method to the barred spiral galaxy NGC 3384, using CCD images in U, B, V, R and I bands. This analysis indicates that the galaxy NGC 3384 is mainly inhabited by old stellar population (age >109yr). Some problems were encountered when numerical simulations are used for determining the contribution of different stellar populations in the integrated color of a galaxy. The results show that the proposed genetic algorithm can search efficiently through the very large space of the possible ages. 相似文献
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Twelve calcareous nannofossil biozones of Late Oligocene-Late Miocene in Northern Egypt were defined and correlated with their corresponding biozones in Egypt and other parts of the world. These are arranged from the top to base as Zone NN12, Zone NN11, Zone NN10, Zone NN8, Zone NN7, Zone NN6 Zone NN5, NN4, Zone NN3, Zone NN2 Zone NP25 and Zone NP24. In the present study (Boughaz-1 Well), the Late Miocene unconformably overlies the Middle Miocene. This unconformity surface is recognized by the missing of calcareous nannofossil zones NN7 to NN9. While, in North Sinai (Malha-1 Well), the Early/Middle Miocene boundary cannot be recognized, where the Middle Miocene unconformably overlies the topmost Oligocene, and it is defined by the missing calcareous nannofossil zones NN1 to NN4. 相似文献
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Mohammad Vaghefi Mohammad Javad Tabib Nazhad Motlagh Seyyed Shaker Hashemi Sahar Moradi 《Arabian Journal of Geosciences》2018,11(5):102
In this study, scouring around piers perpendicular to flow (PPF) and piers toward the flow (PTF) under clear-water condition was examined by placing a set of triad cylindrical piers with a 5-cm diameter and a 15-cm center to center distance at the positions of 60, 90, and 120° of the bend at a constant flow rate of 70 l per second. Natural sand of uniform grain size and average diameter of 1 mm with a uniformity coefficient of 1.3 was used as bed material of the flume. According to the results of this study, the maximum scouring depth occurred in the PPF test situated at the position of 90° of the bend. In such a position, the maximum depth of scouring hole was equal to 1.1 times the depth of the flow at the beginning of the bend. Also, where the piers were positioned in PTF and PPF modes in a 60° angle, the maximum area of scouring hole was observed around piers and sediment piles at the downstream side of the piers. The maximum height of sedimentation occurred in the PPF test situated at the 90° position of the bend. Such a stack was as high as 0.7 times the flow depth at the beginning of the bend and was observed at the 156° position of the bend, at a 20% distance of the flume width from the inner bank. Further results as well as discussion and analysis are among other points presented in the article. 相似文献
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We find a strong correlation between the effective radius of the largest early-type galaxies in compact groups of galaxies and the velocity dispersion of the groups. The lack of a similar correlation for late type galaxies is supportive of the so called second generation merging scenario which predicts that ellipticals should dominate the internal dynamics of the groups, while late-type galaxies are mainly recent interlopers which are still in an early stage of interaction with the group potential. 相似文献
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Hamid Reza Shaker 《Natural Hazards》2014,72(2):1021-1027
Faults in automated systems will often result in undesired behavior and shut-down of the processes. The consequences of these could be damage to the plant, to personnel and resources, or even to the environment. In particular, in the case of natural disasters, faults are often inevitable. The objective of the methods for fault-tolerant control (FTC) is to prevent simple faults turning into severe failure. Therefore, FTC methods help to increase plant availability and to reduce the risk of safety hazards. However, these methods cannot be effective if sufficient redundancy does not exist in the system. A measure for control reconfigurability which reveals the level of redundancy in connection with feedback control is proposed in this paper. The proposed control reconfigurability measure is developed in particular for many applications in which one is interested in analysis and control within a frequency-interval. Compared to the other counterparts, the proposed measure encodes more information on the level of redundancy within the frequency-interval of interest. An illustrative example is given to show the computation of frequency-interval control reconfigurability and its relevance to redundant actuating capabilities in the models. 相似文献
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SHIWenzhong AhmedShaker 《地球空间信息科学学报》2004,7(1):24-30
The exploitation of different non-rigorous mathematical models as opposed to the satellite rigorous models is discussed for geometric corrections and topographic/thematic maps production of high-resolution satellite imagery (HRSI). Furthermore, this paper focuses on the effects of the number of GCPs and the terrain elevation difference within the area covered by the images on the obtained ground points accuracy. From the research, it is obviously found that non-rigorous orientation and triangulation models can be used successfully in most cases for 2D rectification and 3D ground points determination without a camera model or the satellite ephemeris data. In addition, the accuracy up to the sub-pixel level in plane and about one pixel in elevation can be achieved with a modest number of GCPs. 相似文献
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Natural Hazards - The Urmia Lake basin is one of the most important basins in Iran, facing many problems due to poor water management and rainfall reduction. Under current circumstances, it becomes... 相似文献