The Experts below are selected from a list of 5892 Experts worldwide ranked by ideXlab platform
Zhongjian Shen - One of the best experts on this subject based on the ideXlab platform.
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a land use decision approach integrating thermal regulation stormwater management and economic benefits based on urbanization stage identification
Science of The Total Environment, 2021Co-Authors: Chen Liang, Ruochen Zhang, Jian Zeng, Zhongjian ShenAbstract:Abstract Driven by global climate change and urbanization, urban heat island (UHI) and urban storm flood (USF) have become the most frequent and influential hazards in recent decades. Land-use optimization can effectively cope with these hazards. However, the trade-offs between multi-hazard mitigation and economic development impose many limitations in practice. Furthermore, current region-based optimization methods no longer meet the precise management demand, and both Subdivision and Spatial heterogeneity identification have the potential for wider applicability. Hence, a systematic integration of climate adaptation and urban construction through land-use planning is urgently required. This paper proposes a new land-use decision approach for improving climate adaptability of urbanization. This approach involves multi-objective optimization, Spatial Subdivision, and urbanization stage identification, which enable the simultaneous achievement of environmental and economic benefits. Taking Xiamen as case study, the results showed that excessive pursuit of land economic output (LEO) limits the chance of mitigating UHI and USF. Improving the LEO per unit area of construction land could disrupt the link between land exploitation and the increasing side effects of climate hazards. Future urbanization hotspots in Xiamen will likely emerge at the urban fringe in Tong'an District and Xiang'an District. Within each developing unit, the upper limit of construction land was 81.06 hm2 and the green space was recommended to be 7.29-21.94 hm2. Construction land and bare land contributed most to UHI and USF, while forest and grassland were highly efficient in heat and runoff mitigation. The developed approach proved to be effective and practicable, especially for reducing the impacts of extreme UHI and USF.
Sarig Gafny - One of the best experts on this subject based on the ideXlab platform.
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the change in genetic diversity down the core edge gradient in the eastern spadefoot toad pelobates syriacus
Molecular Ecology, 2010Co-Authors: Inbar Munwes, Eli Geffen, Uri Roll, Adam Friedmann, Alon Daya, Yaron Tikochinski, Sarig GafnyAbstract:Several hypotheses are available to predict change in genetic diversity when approaching peripheral populations. We used the eastern spadefoot toad in Israel as a model system to examine these hypotheses using population genetics analyses and network theory. Our results contradicted most of the predictions from the ‘abundant centre’ model, that edge populations should have lower density and lower genetic diversity than core populations. Furthermore, dispersal rate between core and peripheral populations is expected to be asymmetric, mostly directed outwards from the core population, but we did not detect such a trend. Our data did not support the hypothesis of no change or a non-linear change in genetic diversity towards the range edge. However, our results did fit the Fisher (The Genetical Theory of Natural Selection, Clarendon Press, Oxford, 1930) hypothesis, which predicts increase in genetic variability from core to edge of distribution. We attributed this finding to the much harsher climatic and abiotic conditions at the edge, which must be tolerated over generations by both tadpoles and post-metamorphic individuals in this region. Finally, our results have significant conservation implications for the survival of this species in Israel, where it is critically endangered. We identified two distinct communities, which are genetically linked through two specific rain pools in the Upper Galilee. Details on the Spatial Subdivision of this species are cardinal for future management and restoration of temporary wetlands in Israel.
Y. Ohno - One of the best experts on this subject based on the ideXlab platform.
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Breadth-first ray tracing utilizing uniform Spatial Subdivision
IEEE Transactions on Visualization and Computer Graphics, 1997Co-Authors: K. Nakamaru, Y. OhnoAbstract:Breadth-first ray tracing is based on the idea of exchanging the roles of rays and objects. For scenes with a large number of objects, it may be profitable to form a set of rays and compare each object in turn against this set. By doing so, thrashing, due to disk access, can be minimized. We present ways to combine breadth-first methods with traditional efficient algorithms, along with new schemes to minimize accessing objects stored on disk. Experimental analysis, including comparisons with depth-first ray tracing, shows that large databases can be handled efficiently with this approach.
M Ortiz - One of the best experts on this subject based on the ideXlab platform.
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tetrahedral mesh generation based on node insertion in crystal lattice arrangements and advancing front delaunay triangulation
Computer Methods in Applied Mechanics and Engineering, 2000Co-Authors: Raul Radovitzky, M OrtizAbstract:A method of unstructured technical mesh generation for general three-dimensional domains is presented. A conventional boundary representation is adopted as the basis for the description of solids with evolving geometry and topology. The geometry of the surfaces is represented either analytically or by piecewise polynominal interpolation. A preliminary surface mesh is generated by an advancing-front method, with the nodes inserted by hard-sphere packing in physical space in accordance with a prescribed mesh density. Interior nodes are inserted in a face-centered-cubic (FCC) crystal lattice arrangements coupled to octree Spatial Subdivision, with the local lattice parameter determined by a prespecified nodal density function. Prior to triangulation of the volume, the preliminary surface mesh is preprocessed by a combination of local transformations and Subdivisions in order to guarantee that the surface triangulation be a subcomplex of the volume Delaunay triangulation. A joint Delaunay triangulation of the interior and boundary nodes which preserves the modified surface mesh is then constructed via an advancing-front approach. The resulting mesh is finally improved upon by the application of local transformations. The overall time complexity of the mesher is O(N log N). The robustness and versatility of the approach, as well as the good quality of the resulting meshes, is demostrated with the aid of selected examples.
Chen Liang - One of the best experts on this subject based on the ideXlab platform.
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a land use decision approach integrating thermal regulation stormwater management and economic benefits based on urbanization stage identification
Science of The Total Environment, 2021Co-Authors: Chen Liang, Ruochen Zhang, Jian Zeng, Zhongjian ShenAbstract:Abstract Driven by global climate change and urbanization, urban heat island (UHI) and urban storm flood (USF) have become the most frequent and influential hazards in recent decades. Land-use optimization can effectively cope with these hazards. However, the trade-offs between multi-hazard mitigation and economic development impose many limitations in practice. Furthermore, current region-based optimization methods no longer meet the precise management demand, and both Subdivision and Spatial heterogeneity identification have the potential for wider applicability. Hence, a systematic integration of climate adaptation and urban construction through land-use planning is urgently required. This paper proposes a new land-use decision approach for improving climate adaptability of urbanization. This approach involves multi-objective optimization, Spatial Subdivision, and urbanization stage identification, which enable the simultaneous achievement of environmental and economic benefits. Taking Xiamen as case study, the results showed that excessive pursuit of land economic output (LEO) limits the chance of mitigating UHI and USF. Improving the LEO per unit area of construction land could disrupt the link between land exploitation and the increasing side effects of climate hazards. Future urbanization hotspots in Xiamen will likely emerge at the urban fringe in Tong'an District and Xiang'an District. Within each developing unit, the upper limit of construction land was 81.06 hm2 and the green space was recommended to be 7.29-21.94 hm2. Construction land and bare land contributed most to UHI and USF, while forest and grassland were highly efficient in heat and runoff mitigation. The developed approach proved to be effective and practicable, especially for reducing the impacts of extreme UHI and USF.
