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基于小波变换及四元树矢量量化的图象数据压缩算法 被引量:7
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作者 闫敬文 沈贵明 刘劲松 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2000年第2期180-184,共5页
小波变换在时域和频域具有良好的局部化性能 ,因而在图象压缩编码中得到广泛应用 .矢量量化则因为其压缩比大 ,原理和算法相对简单 ,成为图象压缩的又一重要方法 .采用小波变换与四元树矢量量化相结合对二维图象进行编码 .结果表明 ,该... 小波变换在时域和频域具有良好的局部化性能 ,因而在图象压缩编码中得到广泛应用 .矢量量化则因为其压缩比大 ,原理和算法相对简单 ,成为图象压缩的又一重要方法 .采用小波变换与四元树矢量量化相结合对二维图象进行编码 .结果表明 ,该方法可以获得较高的压缩比及 PSNR. 展开更多
关键词 图象压缩 小波变换 四元树矢量量化 算法
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基于小波变换和矢量量化的二维ECG数据压缩算法 被引量:4
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作者 王兴元 孟娟 《中国生物医学工程学报》 CAS CSCD 北大核心 2007年第3期336-341,共6页
本研究针对心电数据的压缩问题,提出了一种新的基于小波变换的二维心电(ECG)数据压缩算法。该算法首先将一维原始ECG信号转化为二维序列信号,从而使ECG数据的两种相关性可得到充分地利用;然后对二维ECG序列进行小波变换,并对变换后的系... 本研究针对心电数据的压缩问题,提出了一种新的基于小波变换的二维心电(ECG)数据压缩算法。该算法首先将一维原始ECG信号转化为二维序列信号,从而使ECG数据的两种相关性可得到充分地利用;然后对二维ECG序列进行小波变换,并对变换后的系数应用了一种改进的矢量量化(VQ)方法。在改进的VQ方法中,根据小波变换后系数的特点,构造了一种新的树矢量(TV)。利用本算法与已有基于小波变换的压缩算法和其他二维ECG信号的压缩算法,对MIT/BIH数据库中的心律不齐数据进行了对比压缩实验。结果表明:本算法适用于各种波形特征的ECG信号,并且在保证压缩质量的前提下,可以获得较大的压缩比,具有一定的应用价值。 展开更多
关键词 ECG压缩 小波变换 矢量量化 树矢量 有效性检验
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基于最小平均复杂度的矢量量化音频分类方法 被引量:1
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作者 陈莘萌 陈刚 姚昱 《武汉大学学报(理学版)》 CAS CSCD 北大核心 2005年第1期69-73,共5页
首先提出了“平均复杂度”的概念,然后由信息熵公式给出了最小平均复杂度的计算方法,并以此为准则构造音频数据的矢量量化树,从而得到音频数据在特征空间的分布情况.根据不同种类的音频数据有不同分布这一事实,比较未知音频与已知音频... 首先提出了“平均复杂度”的概念,然后由信息熵公式给出了最小平均复杂度的计算方法,并以此为准则构造音频数据的矢量量化树,从而得到音频数据在特征空间的分布情况.根据不同种类的音频数据有不同分布这一事实,比较未知音频与已知音频种类的数据在特征空间中的分布情况的近似程度,就可完成音频分类.实验表明,该方法具有适应性强、计算效率高的特点. 展开更多
关键词 平均复杂度 分裂 矢量量化 特征空间 分布 距离
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SAR原始数据压缩技术研究 被引量:4
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作者 关振红 朱岱寅 朱兆达 《南京航空航天大学学报》 EI CAS CSCD 北大核心 2005年第3期325-329,共5页
研究两种合成孔径雷达(SAR)原始数据压缩算法,它们是块自适应树型矢量量化算法和块自适应预测编码算法。前者是在使用穷尽型搜索技术的块自适应矢量量化算法的基础上,通过使用树型搜索算法来提高算法的运行效率;后者是通过预测编码来消... 研究两种合成孔径雷达(SAR)原始数据压缩算法,它们是块自适应树型矢量量化算法和块自适应预测编码算法。前者是在使用穷尽型搜索技术的块自适应矢量量化算法的基础上,通过使用树型搜索算法来提高算法的运行效率;后者是通过预测编码来消除SAR原始数据之间的相关性从而提高压缩性能。结合机载SAR实测原始数据,对讨论的各种算法分别进行压缩和解压缩,并进行SAR成像处理。通过比较和分析各种算法的性能及图像域参数,表明块自适应树型矢量量化算法和块自适应预测编码算法能提高SAR原始数据的压缩性能,比较适合实际工程应用。 展开更多
关键词 合成孔径雷达 数据压缩 块自适应矢量量化 块自适应预测编码
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HRM and Quantitatives: Decision Tree and Vector Analysis in HRM Theory 被引量:2
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作者 Gurhan Uysal 《Chinese Business Review》 2014年第6期382-387,共6页
Research topic of this paper is to discuss theory of Human Resources Management (HRM) and to discuss using of quantitative methods in HRM. Firstly, five variables establish HRM theory. They are HRM practices, positi... Research topic of this paper is to discuss theory of Human Resources Management (HRM) and to discuss using of quantitative methods in HRM. Firstly, five variables establish HRM theory. They are HRM practices, positive organizational behaviors, individual performance, performance of business departments, and firm performance. Transactions among those variables enable Human Resources (HR) practitioners to apply HRM theory in their organizations. Secondly, this paper discusses use of quantitative methods in HRM. They are vector analysis and decision tree analysis. Those analyses enable HR practitioners to make effective HR decisions. Decision tree sets HR alternatives to efficiently implement HRM practices in organizations. Research question is how HR practitioners apply quantitative methods in department of HRM in firms. Finally this research comes out a conclusion that quantitative methods may be used in HRM. 展开更多
关键词 Human Resources Management (HRM) theory VECTORS matrice decision tree quantitative method
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Growth Responses of Trees to Micronutrients and Their Feedback Effect in Various Soil-Forest Ecosystems of Taihu Lake Region
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作者 ZHANGHUANCHAO XUHONGQIANG 《Pedosphere》 SCIE CAS CSCD 2001年第4期311-320,共10页
Vector analysis technique and ecological sequential comparison methods were adopted to study tree growth response to the micronutrients, B, Mo, Cu, Zn, Fe, and Mn, in soils derived from various parent materials in the... Vector analysis technique and ecological sequential comparison methods were adopted to study tree growth response to the micronutrients, B, Mo, Cu, Zn, Fe, and Mn, in soils derived from various parent materials in the forest area of Taihu Lake region in southeast China. The results showed that the dry weight of individual current-year needle of Chinese fir (Cunninghamia lanceolata) grown on the soi1 derived from granite parent rock was increased by 8% and 13% in comparison with that grown on the soils derived from sandstone and ash-tuff parent rock, respectively. And such dry weight of loblolly pine (Pinus taeda) grown on the soil derived from sandstone parent rock was increased by 21% in comparison with that on the soil derived from ash-tuff parent rock. One of the reasons for those results was that micronutrients content in the soil derived from ash-tuff parent rock were not sufficient to meet the requirement of the growth of Chinese fir and loblolly pine, i.e., micronutrients in soil were deficient and/or induced deficient. The amounts of Cu, Zn, Fe, and Mn uptake by Chinese fir and loblolly pine were in agreement with the contents of available micronutrients in soil respectively, except for B and Mo. Meanwhile, there might exist an "antagonism" between the uptake of B versus Mo by trees, although more studies are needed to confirm it. Regression analysis indicated that amount of a soil available micronutrient was correlated to the type of parent material and its total amount in the forest floor, except for B. The F test identified that the correlation of each equation reached the significant level to different extents, respectively. The t test confirmed that amount of available forms was mainly depended on the type of parent material for Mo, Cu, Zn and Mn but on the forest floor for Fe. There was a feedback effect of forest stand on the amount of soil available micronutrients. The ability of accumulating available micronutrients in soil was better by the sawtooth oak (Quercus acutissima) stand than by the Chinese fir stand (except for B). The ability of accumulating available Zn, Fe, Mn and Mo in soil was better by the Chinese fir stand than by the loblolly pine stand, while as for available B and Cu, by the latter was better than by the former. When discussing the effect of forest stand on the amount of soil available micronutrients, not only the amount of micronutrient in the forest floor and the parent materials but also the amount of micronutrient taken up by current-year needles have to be considered. 展开更多
关键词 feedback effect MICRONUTRIENT parent rock tree growth vector analysis
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