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基于多特征的空域替换类图像隐写检测方法 被引量:1
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作者 汤光明 汪滨 王亚弟 《计算机工程》 CAS CSCD 北大核心 2009年第5期144-146,149,共4页
提出一种基于多特征的空域替换类图像隐写检测方法。通过分析空域替换隐写原理,找出空域替换类隐写的共性,分别用位平面纹理相似性和位平面统计相关性以及位平面低比特位随机性来度量和刻画该类隐写对图像位平面间关系属性以及图像位平... 提出一种基于多特征的空域替换类图像隐写检测方法。通过分析空域替换隐写原理,找出空域替换类隐写的共性,分别用位平面纹理相似性和位平面统计相关性以及位平面低比特位随机性来度量和刻画该类隐写对图像位平面间关系属性以及图像位平面属性的影响,由此构建针对空域替换类的隐写检测方法。实验结果表明该方法有效,并具有较高的检测准确性和较强的适应性。 展开更多
关键词 空域替换类隐写 多特征技术 隐写检测 分类器
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基于WWW的图像检索技术 被引量:12
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作者 王欣 《现代图书情报技术》 CSSCI 北大核心 2002年第3期70-73,共4页
在阐释WWW图像信息检索基本原理的基础上,着重介绍并评价了目前图像检索领域主要的检索技术,并列举了几种较为先进的图像检索demo系统,最后对一些制约基于WWW图像检索技术发展的瓶颈问题进行了简要的探讨。
关键词 图像检索 基于内容检索 WWW 多特征检索技术 索引技术 数据模型
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Fluvial reservoir characterization and identification:A case study from Laohekou Oilfield 被引量:4
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作者 张军华 刘振 +3 位作者 朱博华 冯德永 张明振 张学芳 《Applied Geophysics》 SCIE CSCD 2011年第3期181-188,239,240,共10页
Finding channel sandbodies is an important task in oil and gas exploration due to the importance of fluvial reservoirs. It is difficult to describe fluvial reservoirs in detail owing to their frequent changes and seri... Finding channel sandbodies is an important task in oil and gas exploration due to the importance of fluvial reservoirs. It is difficult to describe fluvial reservoirs in detail owing to their frequent changes and serious intersections, as well as limitations of S/N ratio and seismic data resolution. Based on the Laohekou 3D data in Shengli Oilfield, we analyze the general characteristics of fluvial reservoirs in this area, from which we find that they are characterized by strong amplitudes on seismic profiles, high continuity on time slices, and low frequency in the frequency domain. In addition, a cluster of strong string-bead- like reflections was found after color processing and detailed interpretation. To understand this observation, we conduct forward modeling to explain the mechanism. This provides a new way to identify ancient channels in similar areas. By using the multi-attribute fusion and RGB display techniques, channel incision is more obvious and the characteristics of the channel structures are manifested much better. Finally, we introduce and apply multi-wavelet detection technology to identify weaker fluvial reservoir signals. 展开更多
关键词 channel sandbody weak signal string-bead-like reflections attribute fusion multi- wavelet interpretation technology
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Characteristics and Source Identification of Polycyclic Aromatic Hydrocarbons (PAHs) in Urban Soils: A Review 被引量:19
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作者 WANG Chunhui WU Shaohua +2 位作者 ZHOU Shenglu SHI Yaxing SONG Jing 《Pedosphere》 SCIE CAS CSCD 2017年第1期17-26,共10页
Polycyclic aromatic hydrocarbons (PAHs) are mainly produced by combustion processes and consist of a number of toxic com- pounds. They are always emitted as a mixture and have become a major type of pollutants in ur... Polycyclic aromatic hydrocarbons (PAHs) are mainly produced by combustion processes and consist of a number of toxic com- pounds. They are always emitted as a mixture and have become a major type of pollutants in urban areas. The degree of soil contamination by PAHs is of special concern in areas immediately in proximity to cities with heavy traffic, factories, older buildings, and infrastructure. The accumulation of soil PAHs is also affected by non-anthropogenie factors, such as climate, vegetation, and soil property. This paper reviews three typical source identification techniques, including diagnostic ratios, positive matrix factorization, and principle components analysis. The advantages or disadvantages of these techniques are analyzed. It is recommended that multiple identification techniques be used to determine the sources in order to minimize the weaknesses inherent in each method and thereby to strengthen the conclusions for PAH source identification. 展开更多
关键词 anthropogenic factors diagnostic ratios organic pollutants positive matrix factorization principle components analysis soil contamination soil property urban environment
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