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排序方式: 共有326条查询结果,搜索用时 15 毫秒
51.
Milad Janalipour 《International journal of remote sensing》2017,38(1):82-99
Change detection of ground surface objects can provide essential and precious information for experts in the fields of Geomatics, emergency management, urban management, agriculture, and forestry. Space-borne remote-sensing images are one of the main sources for change detection. Various change detection methods have been proposed on remote-sensing applications. However, often, no single efficient method can be selected for a case study because the existing methods sometimes have good performance and sometimes perform poorly. Therefore, it is necessary to propose an integrated change detection method according to some change detection methods. Multi-criteria decision analysis is a powerful framework that can integrate several criteria that may be in contrast to each other. In this study, a multi-criteria decision analysis framework was used to integrate the spectral, textural, and transformed features for detecting building changes with the help of high spatial resolution satellite images. First, the spectral, textural, and transformed features were extracted from the pre- and post-event satellite images. Second, the spectral, textural, and transformed factor maps were produced by entering the related features to three separate Adaptive Network-Based Fuzzy Inference Systems (ANFIS). Third, the ANFIS model was used again to integrate the mentioned factor maps for producing the preliminary building change map. And finally, a comprehensive sensitivity analysis was carried out to determine the proper parameters of the ANFIS models leading to accurate change detection results. The proposed method was tested on the earthquake data set of Bam City in Iran. The achieved results indicated an overall accuracy of 89.62% for identifying the changed and unchanged building regions. Moreover, the obtained results proved the efficiency and accuracy of the proposed method with respect to other implemented methods regarding the Bam earthquake. Furthermore, the aggregation of the spectral, transformed, and textural features resulted in improving the change detection accuracy by about 5–15%, compared with the accuracy of every one of them for the mentioned purpose. 相似文献
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Siamak Molani Taher Azdast Ali Doniavi Milad Moradian Sajjad Mamaghani Shishavan 《塑料、橡胶和复合材料》2018,47(3):106-112
Polypropylene (PP) as a thermoplastic polymer has been foamed using batch foaming process. CO2 is used as the blowing agent of the foaming. Ferrous oxide nanoparticles (nano Fe2O3) are also added as reinforcement. Effect of different parameters including nanoparticle weight percentage, foaming temperature and time on the structural properties of PP/nano Fe2O3 nanocomposites is investigated using Taguchi approach. Scanning electron microscope results depict that an appropriate microcellular structure is obtained with the cell density of 109 cells/cm3 and almost 1 μm of cell size. Analysis of variance results indicated that foaming temperature is the most significant parameter on the structural properties. Cell density and expansion ratio are decreased by increasing foaming temperature. This phenomenon could be due to the reducing melt strength of polymer/gas mixture. It was also inferred that adding 2 wt% of nanoparticles leads to 80% improvement in cell density while cell size and expansion ratio was decreased. 相似文献
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Milad Bahrebar Mohammad Zaman Kabir Mohammad Hajsadeghi Tadeh Zirakian James B. P. Lim 《钢结构国际杂志》2016,16(3):845-855
Steel plate shear walls (SPSWs) are an efficient lateral force-resisting system, and can be designed with corrugated and/or perforated infill plates, depending on structural considerations, architectural requirements, and service design. This paper presents a study on the structural performance of SPSWs with horizontal trapezoidal corrugations and centrally-placed square perforations under monotonic loading. Finite element models were developed for assessment of the buckling stability, stiffness, strength, and ductility performances of the shear walls. To this end, parametric studies were performed by considering the web-plate corrugation angle, thickness, and size of opening as the varying parameters in the nonlinear pushover analyses. It was found that the design of the boundary frame members can be effective in minimizing the deformations imposed by infill plates, providing system ductility, and developing lateral load resistance through stable development of diagonal tension-field action in the web plate. The effects of introducing web-plate perforations, and increasing the size of the opening, on the structural performance were also investigated. Proper design and detailing of the SPSW, along with optimal selection of the web-plate geometrical and corrugation parameters, can ensure desirable structural behavior and seismic performance for such lateral force-resisting systems. 相似文献
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Nano-clay based pigments (NCP) are new type of pigments composed of organic dyes and layered silicate-clay nano-particles, and have already been used in polymeric coatings to improve mechanical thermal and stability properties. In this paper, the basic blue 41(BB41) was intercalated into Na+- montmorillonite in an aqueous medium. The dye-intercalated montmorillonite was centrifuged, dried, and milled to prepare the nanopigment particles. X-ray diffraction showed an increase in the basal spacing, thus confirming intercalation of the BB41 molecules within the nanostructures of the interlayer spaces. Fourier transform infrared spectroscopy was used for identifying the functional groups and chemical bounding of Na+-montmorillonite, BB41 and montmorillonite-BB41. The morphology of NCP was also studied by transmission electron microscopy. Finally, thermo-gravimetric analysis and differential thermograms suggested the thermal stability of the intercalated dye was improved. 相似文献
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Soheil Sadeghi Hossein Nazockdast Milad Mehranpour 《Polymer Engineering and Science》2012,52(10):2182-2195
The main objective of the present work was the study of the effect of organoclay on planar shrinkage anisotropy of polymeric injection‐molded products by means of a rheological technique, in conjunction with birefringence measurements, performed on polycarbonate/organoclay samples. Polarized optical microscopy at elevated temperatures revealed that the birefringence due to the ordered‐silicate layers had a negative contribution to the overall birefringence of the samples. The maximum value of the calculated‐order parameter based on these results was found to be near unity, indicating an appreciable degree of flow alignment for the silicate layers. Different states of silicate layer orientation, with some layers aligned parallel to the in‐plane direction at the skin layer or partially tilted from the planar direction at the core region, were observed through the optical analysis along the thickness direction. The anisotropic shrinkage measurements showed that organoclay reduced both in‐flow and cross‐flow shrinkages, resulting in a low extent of planar shrinkage anisotropy. This can be attributed to the flow alignment of clay particles closely parallel to the in‐plane direction. Prolonged relaxation of the flow‐induced molecular orientation combined with faster solidification were also found to play an appreciable role in the decreased shrinkage anisotropy. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers 相似文献
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Only very few radionuclides exist that decay exclusively by EC-mode without accompanying radiation, 119Sb is one of them. Auger emitter 119Sb (T1/2 = 38.9 h, IEC = 100%) is a potent nuclide for targeted radionuclide therapy based on theoretical dosimetry calculations at a subcellular scale. Auger electron emitting radionuclides in cancer therapy offer the opportunity to deliver a high radiation dose to the tumor cells with high radiotoxicity while minimizing toxicity to normal tissue. 相似文献