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Maoguo Gong Meng Jia Linzhi Su Shuang Wang Licheng Jiao 《International journal of remote sensing》2014,35(11-12):4009-4030
The Yellow River Estuary area of China is under great pressure from both human intervention and natural processes. For analysis of the changes in this area, this article presents a novel change-detection method based on a local fit-search model and kernel-induced graph cuts in multitemporal synthetic aperture radar images. Change detection involves assigning a label to every pixel. This task is naturally formulated in terms of energy minimization, which can be effectively solved by graph cuts. The difference image is transformed implicitly by a kernel function so that an alternative to complex modelling of the original data makes the piecewise constant model become applicable for graph cuts formulation. An issue is that graph cuts are sensitive to the initial estimate. The local fit-search model is proposed to approximate to the local histogram while selecting an optimal threshold for the initial labelling, which leads to an effective constraint for graph cuts and computational benefits as well. Visual and quantitative analyses obtained on the Yellow River Estuary data set confirm the effectiveness of the proposed method and that it outperforms the other state-of-the-art methods of change detection. 相似文献
3.
A beam-column joint of precast and partial steel reinforced concrete( PPSRC) is proposed for precast reinforced concrete frames. The PPSRC consists of partial steel and reinforced concrete. The partial steel is located in the core joint region and the connections between concrete members. This paper presents an experimental study of a series of PPSRC specimens. These specimens are tested under low cyclic loading.Experimental results demonstrate that the bearing capacity of the PPSRC specimens is 3 times that of the ordinary reinforced concrete( RC) beam-column joints. The strength and stiffness degradation rates are slower compared with that of the RC beam-column joints. In addition,the strength of the core joint region and the connections is higher than other parts of the PPSRC specimens. Beam failure occurs firstly for the PPSRC specimens,followed by column failure and connections failure. The failure of the core joint region occurs finally.Test results show that the seismic performance of the PPSRC is better than that of the ordinary RC beam-column joints. 相似文献
4.
UV-curable hyperbranched polyurethane(UV-HBPU) containing carboxyl groups was synthesized from isophorone diisocyanate(IPDI), diethanolamine(DEOA), polyethylene glycol(PEG-400), hydroxyethyl acrylate(HEA), and 2,2-bis(hydroxymethyl) propionic acid(DMPA). The UV-HBPU was used as a negative-type photoresist for a printed circuit board(PCB). Fourier-transform infrared spectroscopy(FTIR) and proton nuclear magnetic resonance(1HNMR) spectroscopy of UV-HBPUs indicated that the synthesis was successful. Differential scanning calorimetry(DSC) and thermogravimetric analysis(TGA) showed that the thermal stability of the UV-HBPUs decreased as the HEA content increased. The polymer exhibited excellent photoresist properties, and the resolution of circuits based on this negative-type photoresist reached 10 μm. 相似文献
5.
纳米掺杂Ag(SnFe)O2电接触合金的研究 总被引:1,自引:0,他引:1
利用化学共沉淀、高能球磨技术及热压烧结等方法制备出纳米掺杂Ag(SnFe)O2触头合金,通过X射线衍射(XRD)、透射电镜(TEM)和冷场发射扫描电镜(FESEM)等对合金触头及其燃弧性能进行了分析。结果发现:Fe元素的加入,使Sn02纳米颗粒在550℃以下焙烧制粉和750℃以下块体烧结成型时都未明显长大,保持在20nm左右,制备的触头合金呈现纳米第二相弥散均匀分布在Ag基体中。在模拟电弧侵蚀试验中,该合金电弧阴极斑点铺展在较大区域,形成多点燃弧形貌,有效降低燃弧时间和电弧电流,分散电弧能量,使阴极斑点没有明显的液体喷溅、Ag的蒸发和第二相的分解,同时非晶的纳米第二相与Ag的润湿性更好,可进一步增加熔体粘度,提高耐电弧侵蚀性能。 相似文献
6.
借助软集合,提出了格蕴涵代数的软LI-理想的概念,研究了软集运算下的一些诸如交、且等基本性质,并给出了格蕴涵代数的软LI-理想的一些等价刻画。此外,研究了格蕴涵代数的软LI-理想与格蕴涵代数的软格理想之间的关系。得到了格蕴涵代数的软LI-理想像与原像的性质。 相似文献
7.
The generalized fuzzy c-means clustering algorithm with improved fuzzy partition (GFCM) is a novel modified version of the fuzzy c-means clustering algorithm (FCM). GFCM under appropriate parameters can converge more rapidly than FCM. However, it is found that GFCM is sensitive to noise in gray images. In order to overcome GFCM?s sensitivity to noise in the image, a kernel version of GFCM with spatial information is proposed. In this method, first a term about the spatial constraints derived from the image is introduced into the objective function of GFCM, and then the kernel induced distance is adopted to substitute the Euclidean distance in the new objective function. Experimental results show that the proposed method behaves well in segmentation performance and convergence speed for gray images corrupted by noise. 相似文献
8.
以醋酸铅和碳酸钠为原料,选择优化的工艺条件,用微乳液法制备得到碳酸铅.结果表明,在S-60为分散剂的微乳液体系中制备得到超细碳酸铅,粒度分布均匀.采用正交实验法得到最佳实验条件:稀释5倍的S-60为分散剂,碳酸铅溶液pH值为2.0,碳酸铅浓度为0.01 mol/L,搅拌速度为1200 rpm. 相似文献
9.
模式识别和支持向量机在复合材料优化设计中的研究和应用 总被引:1,自引:0,他引:1
论述了复合材料设计及优化的基本研究方法,介绍模式识别和支持向量机人工智能法,举例详述复合材料设计及优化中的两种智能法,总结两种智能融合法在复合材料优化设计中的分类、建模、预测等基本研究方法和应用。举例说明模式识别和支持向量机在复合材料优化设计中重要的研究价值。最后对该领域的发展提出若干建议。 相似文献
10.
New energy storage devices such as batteries and supercapacitors are widely used in various felds because of their
irreplaceable excellent characteristics. Because there are relatively few monitoring parameters and limited understanding of their operation, they present problems in accurately predicting their state and controlling operation, such
as state of charge, state of health, and early failure indicators. Poor monitoring can seriously afect the performance of
energy storage devices. Therefore, to maximize the efciency of new energy storage devices without damaging the
equipment, it is important to make full use of sensing systems to accurately monitor important parameters such as
voltage, current, temperature, and strain. These are highly related to their states. Hence, this paper reviews the sensing
methods and divides them into two categories: embedded and non-embedded sensors. A variety of measurement
methods used to measure the above parameters of various new energy storage devices such as batteries and supercapacitors are systematically summarized. The methods with diferent innovative points are listed, their advantages
and disadvantages are summarized, and the application of optical fber sensors is emphasized. Finally, the challenges
and prospects for these studies are described. The intent is to encourage researchers in relevant felds to study the
early warning of safety accidents from the root causes. 相似文献