For many years a soil water content sensor with low cost, reliability and sufficient accuracy has been desirable. Thus, an improved measurement method based on the frequency domain (FD) principle for determining soil ...For many years a soil water content sensor with low cost, reliability and sufficient accuracy has been desirable. Thus, an improved measurement method based on the frequency domain (FD) principle for determining soil water content was considered. Unlike other measurement principles, a new measurable index, η, which was independent of the output impedance and the amplitude of the oscillator while relying on the electrical impedance of a multi-pin probe, was pro- posed. Moreover, a model for processing the impedance of the multi-pin soil probe was developed, and several important electrical parameters for establishing their operating ranges applicable to this probe were evaluated. In order to confirm the theoretical analysis, an experiment was conducted with a 4-pin probe. Using the developed model, the relationship between the proposed index η and soil volumetric water content was shown to be linear (R2 = 0.9921). Thus, as the measurable index, η seemed satisfactory.展开更多
生成对抗网络常常被用于图像着色、语义合成、风格迁移等图像转换任务,但现阶段图像生成模型的训练往往依赖于大量配对的数据集,且只能实现两个图像域之间的转换。针对以上问题,提出了一种基于生成对抗网络的时尚内容和风格迁移模型(con...生成对抗网络常常被用于图像着色、语义合成、风格迁移等图像转换任务,但现阶段图像生成模型的训练往往依赖于大量配对的数据集,且只能实现两个图像域之间的转换。针对以上问题,提出了一种基于生成对抗网络的时尚内容和风格迁移模型(content and style transfer based on generative adversarial network,CS-GAN)。该模型利用对比学习框架最大化时尚单品与生成图像之间的互信息,可保证在时尚单品结构不变的前提下实现内容迁移;通过层一致性动态卷积方法,针对不同风格图像自适应地学习风格特征,实现时尚单品任意风格迁移,对输入的时尚单品进行内容特征(如颜色、纹理)和风格特征(如莫奈风、立体派)的融合,实现多个图像域的转换。在公开的时尚数据集上进行对比实验和结果分析,该方法与其他主流方法相比,在图像合成质量、Inception score和FID距离评价指标上均有所提升。展开更多
A content authentication technique based on JPEG-to-JPEG watermarking is proposed in this paper. In this technique, each 8x8 block in a JPEG compressed image is first processed by entropy decoding, and then the quanti...A content authentication technique based on JPEG-to-JPEG watermarking is proposed in this paper. In this technique, each 8x8 block in a JPEG compressed image is first processed by entropy decoding, and then the quantized discrete cosine transform （DCT） is applied to generate DCT coefficients： one DC coefficient and 63 AC coefficients in frequency coefficients. The DCT AC coefficients are used to form zero planes in which the watermark is embedded by a chaotic map. In this way, the watermark information is embedded into JPEG compressed domain, and the output watermarked image is still a JPEG format. The proposed method is especially applicable to content authentication of JPEG image since the quantized coefficients are modified for embedding the watermark and the chaotic system possesses an important property with the high sensitivity on initial values. Experimental results show that the tamper regions are localized accurately when the watermarked JPEG image is maliciously tampered.展开更多
基金This paper is sponsored by the National Natural Science Foundation of China （No. 60802057, 61071153）, National 863 Plan of China （ 2009AA01Z407 ）, Shanghai Rising-Star Program （10QA1403700）, and Shanghai Educational Development Foundation.
基金Project supported by the National Natural Science Foundation of China (Nos. 30270775 and 30370823) and the DoctorResearch Foundation of the Ministry of Education of China (No. 20030019012)
文摘For many years a soil water content sensor with low cost, reliability and sufficient accuracy has been desirable. Thus, an improved measurement method based on the frequency domain (FD) principle for determining soil water content was considered. Unlike other measurement principles, a new measurable index, η, which was independent of the output impedance and the amplitude of the oscillator while relying on the electrical impedance of a multi-pin probe, was pro- posed. Moreover, a model for processing the impedance of the multi-pin soil probe was developed, and several important electrical parameters for establishing their operating ranges applicable to this probe were evaluated. In order to confirm the theoretical analysis, an experiment was conducted with a 4-pin probe. Using the developed model, the relationship between the proposed index η and soil volumetric water content was shown to be linear (R2 = 0.9921). Thus, as the measurable index, η seemed satisfactory.
文摘生成对抗网络常常被用于图像着色、语义合成、风格迁移等图像转换任务,但现阶段图像生成模型的训练往往依赖于大量配对的数据集,且只能实现两个图像域之间的转换。针对以上问题,提出了一种基于生成对抗网络的时尚内容和风格迁移模型(content and style transfer based on generative adversarial network,CS-GAN)。该模型利用对比学习框架最大化时尚单品与生成图像之间的互信息,可保证在时尚单品结构不变的前提下实现内容迁移;通过层一致性动态卷积方法,针对不同风格图像自适应地学习风格特征,实现时尚单品任意风格迁移,对输入的时尚单品进行内容特征(如颜色、纹理)和风格特征(如莫奈风、立体派)的融合,实现多个图像域的转换。在公开的时尚数据集上进行对比实验和结果分析,该方法与其他主流方法相比,在图像合成质量、Inception score和FID距离评价指标上均有所提升。
基金supported by the National Natural Science Foundation of China under Grant No.60702025the Research Fund for the Doctoral Program of Higher Education under Grant No.20070613024Sichuan Youth Science & Technology Foundation under Grant No.07ZQ026-004
文摘A content authentication technique based on JPEG-to-JPEG watermarking is proposed in this paper. In this technique, each 8x8 block in a JPEG compressed image is first processed by entropy decoding, and then the quantized discrete cosine transform （DCT） is applied to generate DCT coefficients： one DC coefficient and 63 AC coefficients in frequency coefficients. The DCT AC coefficients are used to form zero planes in which the watermark is embedded by a chaotic map. In this way, the watermark information is embedded into JPEG compressed domain, and the output watermarked image is still a JPEG format. The proposed method is especially applicable to content authentication of JPEG image since the quantized coefficients are modified for embedding the watermark and the chaotic system possesses an important property with the high sensitivity on initial values. Experimental results show that the tamper regions are localized accurately when the watermarked JPEG image is maliciously tampered.
文摘压实度是道路、房建、水利等工程领域评价土体压实质量的重要参数,与土体含水率和电导率密切相关。而频域反射技术(frequency domain reflectometry,FDR)可用于快速测定土体含水率和电导率。首先利用频域反射技术分别对多种压实状态下红黏土、膨胀土和黄土的含水率、电导率进行测量;然后对含水率测值进行室内标定,得到3种土的含水率标定曲线;通过偏最小二乘回归分析方法(partial least squares regression,PLSR)建立了3种土体的压实度-含水率-电导率之间的经验关系,并与实测值进行了对比分析;再根据扫描电子显微镜(scanning electron microscopy,SEM)和压汞法(mercury intrusion porosimetry,MIP)试验结果分析了其微观机制;最后对拟合公式得到的压实度预测值进行随机试样验证,建立与实测值的误差评估体系,结果表明基于压实度-含水率-电导率之间的关系而提出的拟合公式预测压实度的精度较高。相关研究可为道路、房建、水利等工程中土体压实度的快速检测提供参考。
