The basal theory of Gauss-MRF is expounded and 2-5 order Gauss MRF models are established. Parameters of the 2-5 order Gauss-MRF models for 300 wood samples＇ surface texture are also estimated by using LMS. The data ...The basal theory of Gauss-MRF is expounded and 2-5 order Gauss MRF models are established. Parameters of the 2-5 order Gauss-MRF models for 300 wood samples＇ surface texture are also estimated by using LMS. The data analysis shows that： 1） different rexture parameters have a clear scattered distribution, 2） the main direction of texture is the direction represented by the maximum parameter of Gauss-MRF parameters, and 3） for those samples having the same main direction, the finer the texture is, the greater the corresponding parameter is, and the smaller the other parameters are; and the higher the order of Gauss-MRF is, the more clearly the texture is described. On the condition of the second order Gauss MRF model, parameter B1, B2 of tangential texture are smaller than that of radial texture, while B3 and B4 of tangential texture are greater than that of radial texture. According to the value of separated criterion, the parameter of the fifth order Gauss-MRF is used as feature vector for Hamming neural network classification. As a result, the ratio of correctness reaches 88%.展开更多
The longitudinal displacement between two reference points upon stress release was measured throgh using the CIRAD-foret one-hole method on a total of 305 trees of 6 eucalyptuses, including Eucalyptus urophylla, E. pe...The longitudinal displacement between two reference points upon stress release was measured throgh using the CIRAD-foret one-hole method on a total of 305 trees of 6 eucalyptuses, including Eucalyptus urophylla, E. pellita, E. teriticornis, E. camaldulensis, E. urophylla x E. grandis and E. urophylla × E. teriticornis. These trees were between 3 to 5 years old and are regarded as commercially important plantation species in China. Significant differences in the growth strain and diameter at breast height over bark （DBHOB） were observed between species, provenances and clones of the same age. The data clearly showed that, E. pellita, E. teriticornis and E. camaldulensis （provenance 15025） had higher growth rates but much lower growth strain at the tree surface, in comparison to other species / hybrids / clones. Whilst conclusive recommendations for species selection need to be substantiated with comprehensive studies that include other key wood properties, results of this study have shown trends pertaining to wood quality differences between the six species.展开更多
基金This paper is supported by the Municipal Natural Science Foundation of Harbin （2004AFX X J 0 20） and Provincial Natural Science Foundation of Heilongjiang （C2004-03）.
文摘The basal theory of Gauss-MRF is expounded and 2-5 order Gauss MRF models are established. Parameters of the 2-5 order Gauss-MRF models for 300 wood samples＇ surface texture are also estimated by using LMS. The data analysis shows that： 1） different rexture parameters have a clear scattered distribution, 2） the main direction of texture is the direction represented by the maximum parameter of Gauss-MRF parameters, and 3） for those samples having the same main direction, the finer the texture is, the greater the corresponding parameter is, and the smaller the other parameters are; and the higher the order of Gauss-MRF is, the more clearly the texture is described. On the condition of the second order Gauss MRF model, parameter B1, B2 of tangential texture are smaller than that of radial texture, while B3 and B4 of tangential texture are greater than that of radial texture. According to the value of separated criterion, the parameter of the fifth order Gauss-MRF is used as feature vector for Hamming neural network classification. As a result, the ratio of correctness reaches 88%.
文摘The longitudinal displacement between two reference points upon stress release was measured throgh using the CIRAD-foret one-hole method on a total of 305 trees of 6 eucalyptuses, including Eucalyptus urophylla, E. pellita, E. teriticornis, E. camaldulensis, E. urophylla x E. grandis and E. urophylla × E. teriticornis. These trees were between 3 to 5 years old and are regarded as commercially important plantation species in China. Significant differences in the growth strain and diameter at breast height over bark （DBHOB） were observed between species, provenances and clones of the same age. The data clearly showed that, E. pellita, E. teriticornis and E. camaldulensis （provenance 15025） had higher growth rates but much lower growth strain at the tree surface, in comparison to other species / hybrids / clones. Whilst conclusive recommendations for species selection need to be substantiated with comprehensive studies that include other key wood properties, results of this study have shown trends pertaining to wood quality differences between the six species.
