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基于光线追踪的尺度效应分析 被引量:1
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作者 张伦 余涛 +2 位作者 顾行发 胡新礼 赵利民 《计算机工程》 CAS CSCD 2014年第4期242-246,共5页
以光线追踪为基础研究尺度变化对图像属性的影响。通过选取地物模型和构建实验场景,实现多分辨率序列图像的模拟仿真。对图像的信息熵、自相关系数、地物覆盖率进行计算和分析,得到以下结论:地物的颜色属性与尺度无关;当图像分辨率降低... 以光线追踪为基础研究尺度变化对图像属性的影响。通过选取地物模型和构建实验场景,实现多分辨率序列图像的模拟仿真。对图像的信息熵、自相关系数、地物覆盖率进行计算和分析,得到以下结论:地物的颜色属性与尺度无关;当图像分辨率降低到一定程度后,图像将会发生失真现象,而当图像分辨率提高到一定程度后,图像的属性将只有很少变化;在不失真范围内,随着图像分辨率的降低,地物覆盖率也随之降低。该结论与传统方法分析的结果趋势相同,但传统方法产生的图像会在更高分辨率时发生失真现象,表明该方法可有效避免图像重采样误差的干扰。 展开更多
关键词 光线追踪 尺度效应 图像仿真 空间自相关系数 失真分辨率 饱和分辨率
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Measurement of Two Phase Flow in Porous Medium Using High-resolution Magnetic Resonance Imaging 被引量:4
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作者 蒋兰兰 宋永臣 +4 位作者 刘瑜 杨明军 朱宁军 王晓静 豆斌林 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第1期85-93,共9页
Measurement of two phase flow in porous medium for sequestration was carried out using high-resolution magnetic resonance imaging (MRI) technique. The porous medium was a packed bed of glass beads. Spin echo multi seq... Measurement of two phase flow in porous medium for sequestration was carried out using high-resolution magnetic resonance imaging (MRI) technique. The porous medium was a packed bed of glass beads. Spin echo multi sequence was used to measure the distribution of CO2 and water in the porous medium. The intensity images show that the fluid distribution is non-uniform due to its viscosity and pore structure of porous medium. The velocity distribution of fluids is calculated from the saturation of water and porosity of porous medium. The experimental results show that fluid velocities vary with time and position. The capillary dispersion rate donated the effects of capillary, which was largest at water saturations of 0.45. The displacement process is different between in BZ-02 and BZ-2. The final water residual saturation depends on permeability and porosity. 展开更多
关键词 two phase flow porous medium magnetic resonance imaging SATURATION CO2 velocity DISPLACEMENT
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