Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λ...Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λa, λc） codewords is said to be maximum. In this paper, the number of codewords of a maximum 2-D （u × v, 4, 1, 3）-OOC has been determined.展开更多
This paper presents a new wavelet transform image coding method. On the basis of a hierarchical wavelet decomposition of images, entropy constrained vector quantization is employed to encode the wavelet coefficients...This paper presents a new wavelet transform image coding method. On the basis of a hierarchical wavelet decomposition of images, entropy constrained vector quantization is employed to encode the wavelet coefficients at all the high frequency bands with展开更多
This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended ...This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended at the end of data bits,which eliminates the overhead of interspersing the redundancy bits at the encoder and decoder.The reliability of memory is further enhanced by the layout architecture of redundancy bits and data bits.The proposed scheme has been implemented in Verilog and synthesized using the Synopsys tools.The results reveal that the proposed method has about 19% less area penalties and 13% less power consumption comparing with the current two-dimensional error codes,and its latency of encoder and decoder is 63% less than that of Hamming codes.展开更多
The desert plant Rhazya stricta has anticancer and antimicrobial properties, and is widely used in indigenous medicines of Saudi Arabia. However, the therapeutic benefits rely on an accurate identification of this spe...The desert plant Rhazya stricta has anticancer and antimicrobial properties, and is widely used in indigenous medicines of Saudi Arabia. However, the therapeutic benefits rely on an accurate identification of this species. The authenticity of R. stricta and other medicinal plants and herbs procured from local markets can be questionable due to a lack of clear phenotypic traits. DNA barcoding is an emerging technology for rapid and accurate species identification. In this study, six candidate chloroplastid barcodes were investigated for the authentication of R. stricta. We compared the DNA sequences from fifty locally collected and five market samples of R. stricta with database sequences of R. stricta and seven closely related species. We found that the coding regions matK, rbcL, rpoB, and rpoC1 were highly similar among the taxa. By contrast, the intergenic spacers psbK-psbI and atpF-atpH were variable loci distinct for the medicinal plant R. stricta. psbK-psbI clearly discriminated R. stricta samples as an efficient single locus marker, whereas a two-locus marker combination comprising psbK-psbI + atpF-atpH was also promising according to results from the Basic Local Alignment Search Tool and a maximum likelihood gene tree generated using PHyML. Two-dimensional DNA barcodes (i.e., QR codes) for the psbK-psbI and psbK-psbI + atpF-atpH regions were created for the validation of fresh or dried R. stricta samples.展开更多
This paper briefly introduces the characteristics and structure of symbol QR two-dimensional code, a detailed analysis of the image processing method to identify QR code of the whole process, and the bilinear mapping ...This paper briefly introduces the characteristics and structure of symbol QR two-dimensional code, a detailed analysis of the image processing method to identify QR code of the whole process, and the bilinear mapping method is applied to image correction, the final steps of decoding are given. The actual test results show that, the design algorithm has theoretical and practical, this recognition system can correctly read QR code, and has high recognition rate and recognition speed, has practical value and application prospect.展开更多
基于特征提取的图像分类算法的核心问题是如何对特征进行有效编码.局部约束线性编码(Locality-constrained linear coding,LLC)因其良好的特征重构性与局部平滑稀疏性,已取得了很好的分类性能.然而,LLC编码的分类性能对编码过程中的近邻...基于特征提取的图像分类算法的核心问题是如何对特征进行有效编码.局部约束线性编码(Locality-constrained linear coding,LLC)因其良好的特征重构性与局部平滑稀疏性,已取得了很好的分类性能.然而,LLC编码的分类性能对编码过程中的近邻数k的大小比较敏感,随着k的增大,编码中的某些负值元素与正值元素的差值绝对值也可能增大,这使得LLC越来越不稳定.本文通过在LLC优化模型的目标方程中引入非负约束,提出了一种新型编码方式,称为非负局部约束线性编码(Non-negative locality-constrained linear coding,NNLLC).该模型一般采取迭代优化算法进行求解,但其计算复杂度较大.因此,本文提出两种近似非负编码算法,其编码速度与LLC一样快速.实验结果表明,在多个广泛使用的图像数据集上,相比于LLC,NNLLC编码方式不仅在分类精确率上提高了近1%～4%,而且对k的选取具有更强的鲁棒性.展开更多
针对屏幕与混合内容视频具有多样性的特点,在我国第二代数字音视频编解码技术标准的屏幕与混合内容视频编码(the second-generation Audio Video Coding Standard Screen and Mixed Content Coding, AVS2-SMCC)扩展版中,提出了由一般串...针对屏幕与混合内容视频具有多样性的特点,在我国第二代数字音视频编解码技术标准的屏幕与混合内容视频编码(the second-generation Audio Video Coding Standard Screen and Mixed Content Coding, AVS2-SMCC)扩展版中,提出了由一般串模式、第一受限串模式和第二受限串模式三种受限串模式组成的通用串预测算法(Universal String Prediction, USP)及其关键技术,其主要部分已经被AVS2-SMCC扩展版工作草案3.0稿采纳.三种受限串模式统一采用偏移串、坐标串和不可预测像素串三种串类型之一或其组合来实现.当编码单元采用USP算法进行编码时,用三种受限串模式对其分别进行预编码,自适应采用三种受限串模式中取得率失真值最小的受限串模式对其进行编码.实验结果表明,对于AVS2-SMCC通用测试序列中移动的文字和图形类别,提出的USP算法与国际上最新的(High Efficiency Video Coding, HEVC)标准SMCC扩展版(High Efficiency Video Coding-Screen Content Coding, HEVC-SCC)相比,在编解码复杂度增加较少的情况下,对于有损全帧内配置 Y 分量、 U 分量、 V 分量平均BD - rate降低率分别可达23.2%、18.3%、19.4%,基于CPSNR的三分量综合的平均BD - rate降低率为22.1%,编码效率已经大幅超过HEVC-SCC.展开更多
基金Supported by the National Natural Science Foundation of China(61071221,10831002)
文摘Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λa, λc） codewords is said to be maximum. In this paper, the number of codewords of a maximum 2-D （u × v, 4, 1, 3）-OOC has been determined.
文摘This paper presents a new wavelet transform image coding method. On the basis of a hierarchical wavelet decomposition of images, entropy constrained vector quantization is employed to encode the wavelet coefficients at all the high frequency bands with
基金Sponsored by the Opening Project of National Key Laboratory of Science and Technology on Reliability PhysicsApplication Technology of Electrical Component(Grant No.ZHD200903)
文摘This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended at the end of data bits,which eliminates the overhead of interspersing the redundancy bits at the encoder and decoder.The reliability of memory is further enhanced by the layout architecture of redundancy bits and data bits.The proposed scheme has been implemented in Verilog and synthesized using the Synopsys tools.The results reveal that the proposed method has about 19% less area penalties and 13% less power consumption comparing with the current two-dimensional error codes,and its latency of encoder and decoder is 63% less than that of Hamming codes.
文摘The desert plant Rhazya stricta has anticancer and antimicrobial properties, and is widely used in indigenous medicines of Saudi Arabia. However, the therapeutic benefits rely on an accurate identification of this species. The authenticity of R. stricta and other medicinal plants and herbs procured from local markets can be questionable due to a lack of clear phenotypic traits. DNA barcoding is an emerging technology for rapid and accurate species identification. In this study, six candidate chloroplastid barcodes were investigated for the authentication of R. stricta. We compared the DNA sequences from fifty locally collected and five market samples of R. stricta with database sequences of R. stricta and seven closely related species. We found that the coding regions matK, rbcL, rpoB, and rpoC1 were highly similar among the taxa. By contrast, the intergenic spacers psbK-psbI and atpF-atpH were variable loci distinct for the medicinal plant R. stricta. psbK-psbI clearly discriminated R. stricta samples as an efficient single locus marker, whereas a two-locus marker combination comprising psbK-psbI + atpF-atpH was also promising according to results from the Basic Local Alignment Search Tool and a maximum likelihood gene tree generated using PHyML. Two-dimensional DNA barcodes (i.e., QR codes) for the psbK-psbI and psbK-psbI + atpF-atpH regions were created for the validation of fresh or dried R. stricta samples.
文摘This paper briefly introduces the characteristics and structure of symbol QR two-dimensional code, a detailed analysis of the image processing method to identify QR code of the whole process, and the bilinear mapping method is applied to image correction, the final steps of decoding are given. The actual test results show that, the design algorithm has theoretical and practical, this recognition system can correctly read QR code, and has high recognition rate and recognition speed, has practical value and application prospect.
文摘基于特征提取的图像分类算法的核心问题是如何对特征进行有效编码.局部约束线性编码(Locality-constrained linear coding,LLC)因其良好的特征重构性与局部平滑稀疏性,已取得了很好的分类性能.然而,LLC编码的分类性能对编码过程中的近邻数k的大小比较敏感,随着k的增大,编码中的某些负值元素与正值元素的差值绝对值也可能增大,这使得LLC越来越不稳定.本文通过在LLC优化模型的目标方程中引入非负约束,提出了一种新型编码方式,称为非负局部约束线性编码(Non-negative locality-constrained linear coding,NNLLC).该模型一般采取迭代优化算法进行求解,但其计算复杂度较大.因此,本文提出两种近似非负编码算法,其编码速度与LLC一样快速.实验结果表明,在多个广泛使用的图像数据集上,相比于LLC,NNLLC编码方式不仅在分类精确率上提高了近1%～4%,而且对k的选取具有更强的鲁棒性.
文摘针对屏幕与混合内容视频具有多样性的特点,在我国第二代数字音视频编解码技术标准的屏幕与混合内容视频编码(the second-generation Audio Video Coding Standard Screen and Mixed Content Coding, AVS2-SMCC)扩展版中,提出了由一般串模式、第一受限串模式和第二受限串模式三种受限串模式组成的通用串预测算法(Universal String Prediction, USP)及其关键技术,其主要部分已经被AVS2-SMCC扩展版工作草案3.0稿采纳.三种受限串模式统一采用偏移串、坐标串和不可预测像素串三种串类型之一或其组合来实现.当编码单元采用USP算法进行编码时,用三种受限串模式对其分别进行预编码,自适应采用三种受限串模式中取得率失真值最小的受限串模式对其进行编码.实验结果表明,对于AVS2-SMCC通用测试序列中移动的文字和图形类别,提出的USP算法与国际上最新的(High Efficiency Video Coding, HEVC)标准SMCC扩展版(High Efficiency Video Coding-Screen Content Coding, HEVC-SCC)相比,在编解码复杂度增加较少的情况下,对于有损全帧内配置 Y 分量、 U 分量、 V 分量平均BD - rate降低率分别可达23.2%、18.3%、19.4%,基于CPSNR的三分量综合的平均BD - rate降低率为22.1%,编码效率已经大幅超过HEVC-SCC.
