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对小波基分类是图像融合中依据不同融合需求选择小波基的基础,可以提高图像融合的智能化水平。针对现有的小波基分类方法仅根据小波自身特性进行分类,没有从统计角度有效建立小波基和图像差异特征之间的联系,本文提出了面向图像差异特征融合的基于弗里德曼检验的小波基分类方法。首先,选择典型的差异特征和小波基用于分类研究;其次,选择针对差异特征的评价指标,以评价指标结果作为标记量并进行分类实验的区组设计;然后,采用弗里德曼检验对不同区组数据进行处理及执行相应的后续检验和分类步骤,形成面向图像差异特征的小波基类集;最后,设计对比实验对分类方法的有效性进行验证和分析。试验结果表明,该分类方法能有效把对图像差异特征融合效果相近的小波基归为一类,能根据融合需求选择较好的小波基。 相似文献
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4H-SiC junction barrier Schottky(JBS)diodes with four kinds of design have been fabricated and characterized using two different processes in which one is fabricated by making the P-type ohmic contact of the anode independently,and the other is processed by depositing a Schottky metal multi-layer on the whole anode.The reverse performances are compared to find the influences of these factors.The results show that JBS diodes with field guard rings have a lower reverse current density and a higher breakdown voltage,and with independent P-type ohmic contact manufacturing,the reverse performance of 4H-SiC JBS diodes can be improved effectively. Furthermore,the P-type ohmic contact is studied in this work. 相似文献
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We have investigated the temperature dependent interfacial and electrical characteristics of p-GaAs metal-oxide-semiconductor capacitors during atomic layer deposition(ALD) and annealing of HfO2 using the tetrakis(ethylmethyl) amino hafnium precursor. The leakage current decreases with the increase of the ALD temperature and the lowest current is obtained at 300℃ as a result of the Frenkel-Poole conduction induced leakage current being greatly weakened by the reduction of interfacial oxides at the higher temperature. Post deposition annealing(PDA) at 500℃ after ALD at 300℃ leads to the lowest leakage current compared with other annealing temperatures. A pronounced reduction in As oxides during PDA at 500℃ has been observed using X-ray photoelectron spectroscopy at the interface resulting in a proportional increase in Ga2O3. The increment of Ga2O3 after PDA depends on the amount of residual As oxides after ALD. Thus, the ALD temperature plays an important role in determining the high-k/GaAs interface condition. Meanwhile, an optimum PDA temperature is essential for obtaining good dielectric properties. 相似文献
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基于器件工作机理,提出了一种新型的4H-SiC MESFET经验大信号电容模型。模型参数提取采用Lev-enberg-Marquardt优化算法,提取的模型主要参数具有一定物理意义。C-V特性的模型模拟结果与实验数据的比较表明两者符合良好。该模型还与CAD工具的通用电容模型进行了比较,结果表明新模型具有更高的精度。 相似文献
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针对4H-SiC射频MESFET中的自热效应,建立了基于解析模型的材料参数温度模型和器件直流模型.研究了由陷阱造成的背栅效应,并结合材料的温度特性分析了温度升高对器件特性的影响.分析了陷阱对器件特性的影响,并进一步阐明了陷落-发射机制.计算得到陷阱能级为1.07eV,俘获截面为1×10-8cm2,器件的自升温达到100K以上,能够较好地反映实验结果.分析结果表明,背栅电势随陷阱浓度的增大而增大,并随着漏极电压的增大而减小,在室温下达到~3V.另外,由于器件中存在自热效应,背栅电势随漏压的变化加剧.这些模拟分析对实际器件的设计及工艺制造提供了理论上的依据. 相似文献
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采用分子束外延设备(MBE),外延生长了InAs/AlSb二维电子气结构样品.样品制备过程中,通过优化AlGaSb缓冲层厚度和InAs/AlSb界面厚度、改变AlSb隔离层厚度,分别对比了材料二维电子气特性的变化,并在隔离层厚度为5nm时,获得了室温电子迁移率为20500cm~2/V·s,面电荷密度为2.0×1012/cm~2的InAs/AlSb二维电子气结构样品,为InAs/AlSb高电子迁移率晶体管的研究和制备提供了参考依据. 相似文献