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A study of the visual physical characteristics and psychological images of select Taiwanese hardwoods.

Abstract

This study investigated the relationship between visual images of wood color and wood grains of wood products manufactured from select Taiwanese commercial hardwoods. The Taiwan Forestry Research Institute provided samples for 23 species of commercially available woods, each with tangential and radial sections (46 samples total). Wood color parameters were measured, followed by a survey using a Semantic Differential scaling method to discern the consumers' mental perception toward the wood products. Finally, factors involved in constructing different images underwent statistical analysis to offer designers and consumers a reference for designing a product or wood product selections. Among Taiwan's commercial woods, Swietenia mahogoni was perceived to be advanced, elegant, and exquisite in the tangential section and warm, soft, and possessive of a natural image in the radial section. The tangential section of Paulownia taiwaniana was perceived to possess a common image; meretricious and rough images were associated with the tangential section of Cassia siamea. Cold and hard images were associated with the tangential and radial sections of Actinodaphne nantoensis, and Cyclobalanopsis longinux was perceived to possess an artificial image. In terms of color (Commission Internationale d'Eclairage L*a*b*), the relative images of advanced and common, elegant and meretricious, and warm and cold were closely related to L* and a*; the relative images of exquisite and rough and of soft and hard were related to a*. In terms of grains, the relative images of soft and hard and of natural and artificial are closely related to thickness of the wood lines.

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Use of wood products in design (product design or space design) has become more fashionable. Designers can use shape, color, and material type to achieve a given impression, but consumers may feel differently. Therefore, understanding what impressions are conveyed by different species and design offerings should facilitate designers' communication with their consumers and result in production of products that are psychologically appealing to consumers. Thus, if designers have knowledge regarding the physical characteristics of wood and know how those characteristics influence a consumer emotionally, they can design a product or space that meets the user's psychological needs.

A number of in-depth studies have examined the relationship between product design and human emotions and senses. Hsu et al. (2004) investigated the differences in product form and perception between designers and users. Those authors used the Semantic Differential scaling method to measure the relationship between the subjects' evaluation of telephones and design form elements. Alcantara (2005) applied the Semantic Differential method to structure the semantic space of footwear. Hsiao and Huang (2002) applied a back-propagation neural network to establish between product-form parameters and adjective-based image words; those authors used a chair design for a case study. Lai et al. (2006) used Type I Theory and neural networks of user-oriented design for transforming consumers' perceptions into product element design, and Horiguchi and Suetomi (1995) used the Kansei engineering method to evaluate the interior images of vehicles.

The literature regarding wood textures include Yamada and Shiraishi (2006), who suggested that the grain direction of wood texture could influence the visual perception of the spatial dimension. Takahashi et al. (1995) emphasized, in accordance with the five-senses analysis of wood materials, that the affinity of wood grain image as well as the warmness of colors influence wood fiber visual reflection in a painting. Those authors also investigated whether the amount of wood vessels affects the visual brightness of a painting. Kobayashi et al. (2006) proposed that specialists have different viewpoints on the visual image of wood textures from those of average consumers. Their premise was that specialists undertake the visual analysis by a method of physical measurement, so their perception of the wood texture visual image is more consistent. The analysis by Shiraishi et al. (2006) indicated that generic processed materials were similar in visual and tactile aspects. In Nakatsuka and Aoyama (2006), the results indicated that the use of naturally occurring patterns and images on man-made materials can be used successfully to manufacture a product that is perceived as natural. Furthermore, Masuda (1985a, 1985b) utilized artificial wood grain printed on paper to conduct a visual-sychological experiment, the results of which indicated that different wood species have different psychological characteristics, mainly from the color of the wood grain and daily usage. Nordvik et al. (2009) used the Kansei engineering methodology to evaluate the visual cognition of human response toward wood flooring. Iniguez et al. (2007) conducted an in-depth study of visual grades for a large volume of structural sawn timber from Spanish coniferous species.

Currently, many countries are endeavoring to protect their local culture as well as promote and develop ways to utilize indigenous materials. Countries with unique indigenous materials can market the uniqueness of the local products using cultural linkages. Further research and development of products from different regions may boost trade and cooperation. Along these lines, the present study used a systematic investigation and analysis of wood products manufactured from commercial hardwoods found in Taiwan. The results will provide a reference for application and research of related designs and for evaluating the relationships between visual image, color, and grain by correlation analysis.

Materials and Methods

The samples used in the present study were composed of 23 commercial hardwood species found in Taiwan (Table 1). In total, 46 samples, which included one sample each from the tangential and radial sections for each tree species, were evaluated. Samples were supplied by the Taiwan Forestry Research Institute. The tangential section was sawn parallel to the trunk and cut longitudinally without passing through the pith of the tree; the rings had either a U- or a V-shaped pattern (Fig. 1A). The radial section was sawn parallel to the trunk and cut longitudinally through the pith of a tree, which yielded a straight grain pattern (Fig. 1B).

The physical characteristics of color as well as grain characteristics were measured. For color, a spectral colorimeter (SCM-108) was used to measure the physical characteristics of hue and brightness on each sample. The lighting was a D65 standard light source; the correlated color temperature was 6,504 K. The geometrical angle of the lighting and observation was 0/d (normal incident/ diffuse reflection) at 10[degrees], and the measurement range was [PHI]25mm.The color parameters were the average of a multipoint test (five points) on the tangential and radial sections of each species. The study of wood color was presented in a Commission Internationale d'Eclairage (CIE) [L.sup.*][a.sup.*][b.sup.*] color space, where [L.sup.*] = 0 is black, [L.sup.*] = 100 is white, a negative [a.sup.*] is green, a positive [a.sup.*] is red, a negative [b.sup.*] is blue, and a positive [b.sup.*] is yellow. Also, I had characterized the grains for each sample by having experts from the Taiwan Forestry Research Institute classify the grain characteristics as to grain orientation.

A Semantic Differential questionnaire uses adjectives to measure the subjects' assessment of the samples. In all, 116 adjectives were collected regarding the wood materials, and from these, six experts selected 26 adjectives, which were then compiled into a Semantic Differential questionnaire. The questionnaires were statistically analyzed. In consultation with experts, I reduced the adjectives to six groups: advanced [left and right arrow] common, elegant [left and right arrow] meretricious, exquisite rough, warm [left and right arrow] cold, soft [left and right arrow], hard, and natural [left and right arrow] artificial. The questions were designed on a 5-point scale from "in complete agreement" to "no opinion." For each question, the center point was 0, indicating "no opinion," with 2 and -2 indicating "in complete agreement." The participants were placed in an environment where the color temperature was 6,000 K as the experimental items were placed in a standard color-temperature box. The subjects reviewed and assessed one sample after another and immediately completed the questionnaire. The number of questionnaires distributed and completed totaled 72 (100% response rate).

[FIGURE 1 OMITTED]

For each sample, an average rating value was computed. To represent the results numerically, I transformed the values from ordinal to interval--for example, transforming the scale ordinal numbers (-2,- 1, 0, 1, 2) into scale interval numbers (1, 2, 3, 4, 5). Thus, when the average is less than 3, the perception is closer to the left side, and the smaller the number, the stronger the perception. When the average is greater than 3 the perception is closer to the right side, and the larger the number, the stronger the opinion. For example, when the average interval is 4.36 (>3), it indicates that the perception is quite strong. In addition, a one-sample t test was used to contrast the average of the population and the specified constant. In addition, biserial correlation was used to study the relationship between the images and [L.sup.*], [a.sup.*], and [b.sup.*], and the I had used tetrachoric correlation analysis to assess the relationship between the images and grain patterns.

Results and Discussion

Table 2 presents the parameters for wood color in a CIE [L.sup.*][a.sup.*][b.sup.*] color space. The measured value of color can be presented as a plane projection (as presented in Fig. 2). The scatter diagram represents the projection position of the measured value at the [a.sup.*]-[L.sup.*] plane (x axis, [a.sup.*]; y axis, [L.sup.*]) and the [b.sup.*]-[L.sup.*] plane (x axis, [b.sup.*]; y axis, [L.sup.*]), respectively. Figure 2 presents the range of the 46 samples. Brightness [L.sup.*] is between 34 and 75, colorfulness [a.sup.*] between 4 and 16, and colorfulness [b.sup.*] between 15 and 26.

From Table 3, which presents the results of the one-sample t test, I concluded that each descriptor adjective (P < 0.05) corresponds to a discrete species. In the first group, I examined advanced [left and right arrow] common. From this, the sample with the most advanced image was the tangential section of Swietenia mahogoni, and the sample with the most common image was the tangential section of Paulownia taiwaniana. In the second group, I assessed elegant [left and right arrow] meretricious. From this selection, the sample with the most elegant image was the tangential section of S. mahogoni, and the sample with the most meretricious image was the tangential section of Cassia siamea. In the third group, I measured exquisite rough. From this section, the sample with the most exquisite image was the tangential section of S. mahogoni, and the sample with the roughest image was the tangential section of C. siamea. In the fourth group, I assessed warm [left and right arrow] cold. The results indicated that the sample with the warmest image was the tangential section of S. mahogoni, and the sample with the coldest image was the tangential section of Litsea acuminate. In the fifth group, soft [left and right arrow] hard, the sample with the softest image was the radial section of S. mahogoni, and the sample with the hardest image was the radial section of L. acuminate. In the sixth group, natural artificial, the sample with the most natural image was the radial section of Michelia compressa, and the sample with the most artificial image was the radial section of Cyclobalanopsis longinux.

In the analysis of visual physical characteristics and cognitive psychology of materials, I used biserial correlation analysis to study the relationship between the images and [L.sup.*], [a.sup.*], and [b.sup.*]. Quarter correlation analysis was also used to see the relationship between image and grains. The adjectives were treated as binary variables, with advanced, elegant, exquisite, warm, soft, and natural set as 1 and their counterparts (i.e., common, meretricious, rough, cold, hard, and artificial, respectively) set as 0. In correlation analysis of colors of hardwoods using the images of our samples, I found that some adjectives and their counterparts were highly related to wood color. As presented in Table 4, advanced and common, elegant and meretricious, and warm and cold are highly correlated to [L.sup.*]. Exquisite and rough as well as soft and hard are correlated to [a.sup.*]. Natural and artificial are not correlated to [L.sup.*], [a.sup.*], or [b.sup.*].

[FIGURE 2 OMITTED]

Advanced [left and right arrow] common image analysis

The relative image of advanced and common, as shown in Table 4, achieves the significance level of 0.01 (for color [L.sup.*], r = -0.468 and P < 0.01), so it can be concluded that advanced and common are negatively correlated to [L.sup.*]. In color [a.sup.*], r = 0.665 and P < 0.01. Thus, it achieves the significance level of 0.01, so it can be concluded that advanced and common are positively correlated to [a.sup.*]. In other words, in hardwoods, the species with a perception of advanced image has a low [L.sup.*] and a high [a.sup.*], and the species with a perception of a common image has a high [L.sup.*] and a low [a.sup.*]. Accordingly, once the lightness of the hardwood turns low, the hue turns toward reddish, such as the radial section of S. mahogoni ([L.sup.*] = 51.59, [a.sup.*] = 15.27), which gives the impression of advanced, whereas when the lightness turns high, the hue turns toward greenish, such as the tangential section of P. taiwaniana ([L.sup.*] = 70.32, [a.sup.*] = 6.34), which gives the impression of common in the image analysis.

Elegant [left and right arrow] meretricious image analysis

The relative image of elegant and meretricious, as shown in Table 4, achieves the significance level of 0.05 (in color [L.sup.*], r = -0.392 and P < 0.01), so it can be concluded that elegant and meretricious are negatively correlated to [L.sup.*]. In color [a.sup.*], r = 0.710 and P < 0.01. Thus, it reaches the standard of 0.01, and it can be concluded that elegant and meretricious are positively correlated to [a.sup.*]. In other words, in a broad-leaved tree, the species with the perception of elegant image has a low [L.sup.*] and a high [a.sup.*], and the species with the perception of meretricious image has a high [L.sup.*] and a low [a.sup.*]. Accordingly, when the lightness is low, the hue of hardwood turns toward reddish, such as the tangential section of S. mahogoni ([L.sup.*] = 51.59, [a.sup.*] = 15.27), which gives an impression of elegant, whereas when the lightness is high, hardwood turns greenish, such as the tangential section of Cassia siamea ([L.sup.*] = 61.46, [a.sup.*] = 7.37), which gives an impression of meretricious in the image analysis.

Warm [left and right arrow] cold image analysis

The relative image of warm and cold, as shown in Table 4, achieves the significance level of 0.01 (in color [L.sup.*], r = 0.593, P < 0.01), so it can be concluded that warm and cold are negatively correlated to [L.sup.*]. In color [a.sup.*], r = 0.768 and P < 0.01. Thus, it achieves the significance level of 0.01, and it can be concluded that warm and cold are positively correlated to [a.sup.*]. In other words, in hardwoods, a species with the perception of warm image has a low [L.sup.*] and a high [a.sup.*], whereas the species with a perception of cold image has a high [L.sup.*] and a low [a.sup.*]. Thus, among hardwoods, when the lightness is low and the hue is toward reddish, such as the tangential section of S. mahogoni ([L.sup.*] = 50.85, [a.sup.*] = 15.14), this tends to give a warm feeling, whereas when the lightness is high and the hue is toward greenish, such as the tangential section of L. acuminate ([L.sup.*] = 59.02, [a.sup.*] = 5.13), this tends to give the impression of a cold feeling.

Exquisite [left and right arrow] rough image analysis

The relative image of exquisite and rough, as shown in Table 4, achieves the significance level of 0.01 (in color [a.sup.*], r = 0.696 and P < 0.01), and it can be concluded that exquisite and rough are positively correlated to [a.sup.*]. In other words, in hardwoods, the species with a perception of exquisite image has high [a.sup.*], and the species with a perception of rough image has a low [a.sup.*] value. Accordingly, once the hue turns toward reddish, such as the tangential section of S. mahogoni ([a.sup.*] = 15.27), it is exquisite, whereas once the hue turns toward greenish, such as the tangential section of Cassia siamea ([a.sup.*] = 7.37), it becomes rough.

Soft [left and right arrow] hard image analysis

The relative image of soft and hard, as shown in Table 4, achieves the significance level of 0.01 (in color [a.sup.*], r = 0.694 and P < 0.01), so it can be concluded that soft and hard are positively correlated to [a.sup.*]. In other words, in hardwoods, the species with the perception of a soft image has a high [a.sup.*], and the species with a perception of a hard image has a low [a.sup.*]. Accordingly, once the hue turns toward reddish, such as the radial section of S. mahogoni ([a.sup.*] = 15.14), it becomes soft, whereas once the hue turns toward greenish, such as the radial section of L. acuminate ([a.sup.*] = 4.44), it is considered to be hard.

Natural [left and right arrow] artificial image analysis

The relative image of natural and artificial is not related to [L.sup.*] (brightness), [a.sup.*] (red-green), or [b.sup.*] (yellow-blue). This indicates that neither lightness nor hue creates a difference in perception between natural or artificial.

Grain analysis

In correlation analysis of grains of hardwoods and images, the relationship between the grain and images was investigated using tetrachoric correlation. The adjectives were treated as binary variables, and the grain characteristics of growth rings (clear/ring porous or unclear/diffuse porous), section (tangential or radial), and rays (thick or thin) were also treated as binary variables. As a result, no correlation between images and veins (clear or unclear) and sections (tangential or radial) was found. However, the thickness of rays, which is a feature of hardwoods, was found to be correlated with the soft/hard and natural/ artificial look. These results are presented in Table 5.

Summary and Conclusions

From the study of the attributes that constitute the visual images of wood materials, conducted by assessing wood color ([L.sup.*], [a.sup.*], and [b.sup.*]), analysis of grain characteristics, utilization of a Semantic Differential questionnaire to explore consumers' perception toward wood materials, and statistical analysis of the images of different woods, the following was discerned:

1. The grain appearance of hardwoods can be generally divided into clear and unclear types. The variance range of brightness [L.sup.*] was between 34 and 75, colorfulness [a.sup.*] between 4 and 16, and colorfulness [b.sup.*] between 15 and 26. Thus, samples of Taiwanese commercial timbers in the present study tended more toward yellowish and reddish.

2. The advanced, elegant, and exquisite findings for Taiwan's commercial broad-leaved trees were from the tangential sections of S. mahogoni. The warm, soft, and natural images were found in the radial sections of S. mahogoni. In addition, the common image was discerned in the tangential section of P. taiwaniana. Meretricious and rough perceptions were associated with the tangential sections of Cassia siamea and cold and hard perceptions with the tangential/radial sections of L. acuminate. Lastly, the artificial image was discerned in C. longinux. These results indicate that S. mahogoni has a particularly high value-added potential based on consumer preferences and, as such, should be targeted for future commercial timber plantations/production.

3. Through correlation analysis, I found that in hardwoods, the relative perception of advanced and common, elegant and meretricious, and warm and cold were highly correlated to [L.sup.*] and [a.sup.*]. The more advanced, elegant, or warm the perception was, the lower the [L.sup.*] and the higher the [a.sup.*] (i.e., lower brightness and more red); the more common, meretricious, or cold the image was, the higher the [L.sup.*] and lower the [a.sup.*] (i.e., higher brightness and lower red). The relative images of exquisite and meretricious as well as soft and hard were related to colorfulness [a.sup.*]. The more exquisite and soft the perception was, the higher the [a.sup.*] (colorfulness) and the more red the color. The more meretricious and hard the perception rating was, the lower the [a.sup.*] and the less red the color. Regarding the clarity of the growth rings, the tangential/radial section was not related to images of the species. For the thickness of rays, which is a prominent feature of broad-leaved trees, the rays related to soft and hard and to natural and artificial. The sample with soft and natural images had thinner rays, whereas the sample with hard and artificial images had thicker rays. Based on the materials used, wood colors that tend toward reddish and less brightness, such as S. mahogoni, are more frequently perceived as advanced, elegant, and warm, whereas the reverse are perceived as common, meretricious, and cold. Materials with thin rays easily generate soft and natural images.

Acknowledgments

The author is grateful to National Science Council of Taiwan for their partial financial support fund (NSC 96-2221-E-027-102). The author also appreciates the Taiwan Forestry Research Institute for providing the samples.

Literature Cited

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Iniguez, G., F. Arriaga, J. D. Barrett, and M. Esteban. 2007. Visual grading of large structural coniferous sawn timber according to Spanish standard UNE 56544. Forest Prod. J. 57(10):45-50.

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The author is Associate Professor, Dept. of Industrial Design, National Taipei Univ. of Technology, Taipei, Taiwan (chentl@ntut.edu.tw). This paper was received for publication in April 2011. Article no. 11-00053.
Table 1.--Species of hardwoods in Taiwan.

No.   Species

 1    Michelia compressa
 2    Trochodendron aralioides
 3    Cinnamomum camphora
 4    C. micranthum
 5    Machilus kusanoi
 6    Litsea acuminate
 7    Sasafras randaiense
 8    Cassia siamea
 9    Acacia confuse
10    Schefflera octophylla
11    Alnus formosana
12    Cyclobalanopsis gilva
13    C. longinux
14    Castanopsis carlesii
15    Lithocarpus amygdalifolius
16    Pasanea brevicaudata
17    P. ternaticupula
18    Zelkova serrata
19    Trema orientales
20    Schima superba
21    Fraxinus formosana
22    Paulownia taiwaniana
23    Swietenia mahogoni

Table 2.--Measured color parameters of hardwoods. (a)

                                    Tangential section

Species                      [L.sup.*]   [a.sup.*]   [b.sup.*]

Michelia compressa             42.06        6.07       22.91
Trochodendron aralioides       65.50       10.49       23.77
Cinnamomum camphora            65.63       10.30       21.77
C. micranthum                  53.01       11.44       22.08
Machilus kusanoi               60.40        7.56       18.72
Litsea acuminate               59.02        5.13       19.00
Sasafras randaiense            38.79        7.72       15.14
Cassia siamea                  61.46        7.37       24.34
Acacia confuse                 44.87       11.37       17.41
Schefflera octophylla          74.62        5.13       18.74
Alnus formosana                69.33        8.46       22.10
Cyclobalanopsis gilva          46.88       13.05       19.89
C longinux                     45.32       13.55       21.62
Castanopsis carlesii           68.45        7.60       21.16
Lithocarpus amygdalifolius     42.14        8.29       15.79
Pasania brevicaudata           59.60       10.13       21.51
P. ternaticupula               50.38        8.95       17.99
Zelkova serrata                47.54       14.52       24.72
Trema orientalis               52.05        7.76       17.14
Schima superb                  60.82        9.56       19.68
Fraxinus formosana             69.61        8.91       24.65
Paulownia taiwaniana           70.32        6.34       20.61
Swietenia mahogoni             51.59       15.27       23.48

                                      Radial section

Species                      [L.sup.*]   [a.sup.*]   [b.sup.*]

Michelia compressa             53.68        6.68       25.16
Trochodendron aralioides       66.40       11.56       25.13
Cinnamomum camphora            63.11       10.46       21.90
C. micranthum                  55.82       10.75       21.47
Machilus kusanoi               60.22        7.88       22.29
Litsea acuminate               59.05        4.44       18.87
Sasafras randaiense            40.96        6.98       15.64
Cassia siamea                  51.31        8.60       23.77
Acacia confuse                 45.79       11.26       17.17
Schefflera octophylla          75.00        4.86       16.08
Alnus formosana                70.94        8.99       22.53
Cyclobalanopsis gilva          34.98       10.28       15.75
C longinux                     40.00       10.88       17.21
Castanopsis carlesii           71.82        6.58       20.61
Lithocarpus amygdalifolius     48.17        6.83       16.90
Pasania brevicaudata           52.10        9.03       18.45
P. ternaticupula               52.08       11.69       20.77
Zelkova serrata                40.50       15.70       20.74
Trema orientalis               59.27       11.53       23.15
Schima superb                  61.29       10.46       20.36
Fraxinus formosana             69.04        7.56       21.53
Paulownia taiwaniana           69.20        6.37       19.14
Swietenia mahogoni             50.85       15.14       23.42

[L.sup.*] = brightness; [a.sup.*] = colorfulness index (red green
axis); [b.sup.*] = colorfulness index (yellow-blue axis).

Table 3.--One-sample t test of species. (a)

                                                Tangential section

(Group) Imagery    Species                 Mean    t value       SD

(1) Advanced       Cinnamomun micranthum    --         --         --
                   Acacia confuse          2.403    -4.420 ***   1.146
                   Cyclobalanopsis         2.708    -2.119 *     1.168
                     longinux
                   Schima superba          2.361    -4.554 ***   1.190
                   Swietenia mahogoni      1.931    -9.984 ***   0.909

(1) Common         Michelia.formosana       --         --         --
                   Cinnamomum camphora     3.542     4.040 ***   1.138
                   C. micranthum           3.361     2.391 *     1.282
                   Machilus kusanoi        3.611     4.578 ***   1.133
                   Actinodaphne            3.764     6.307 ***   1.028
                     nantoensis
                   Cassia siamea           3.847     6.018 ***   1.195
                   Schefffera actophylla   3.542     3.629 ***   1.266
                   Alnus formosana          --         --         --
                   Cyclobalanopsis          --         --         --
                     longinux
                   Castanopsis carlesii    3.750     5.668 ***   1.123
                     hay
                   Pasania brevicaudata    3.375     2.782 **    1.144
                   P. ternaticupula        3.500     3.409 ***   1.245
                   Trema orientales        3.806     6.237 ***   1.096
                   Fraxinus formosana       --         --         --
                   Paulownia taiwaniana    3.887     8.927 ***   0.838

(2) Elegant        Cinnamomun micranthum    --         --         --
                   Acacia confuse          2.458    -3.875 ***   1.186
                   Cyclobalanopsis gilva   2.681    -2.412 *     1.124
                   C.longinux              2.569    -3.288 **    1.111
                   Zelkovaformosana        2.681    -2.311 *     1.173
                   Schima superba          2.208    -6.414 ***   1.047
                   Fraxinus formosana      2.611    -2.979 **    1.108
                   Swietenia mahogoni      1.944   -10.105 ***   0.886

(2) Meretricious   Michelia formosana       --         --         --
                   Cinnamomum camphora     3.458     3.457 ***   1.125
                   Machilus kusanoi        3.333     2.272 *     1.245
                   Actinodaphne            3.583     4.511 ***   1.097
                     nantoensis
                   Cassia siamea           3.889     7.145 ***   1.056
                   Schefera actophylla     3.306     2.000 *     1.296
                   Cyclobalanopsis          --         --         --
                     longinux
                   Castanopsis carlesii    3.667     5.697 ***   0.993
                     hay
                   Pasania ternaticupula   3.486     3.408 **    1.210
                   Trema orientalis        3.736     5.317 ***   1.175
                   Paulownia taiwaniana    3.817     6.853 ***   1.004

(3) Exquisite      Cinnamomun micranthum    --         --         --
                   Acacia confuse          2.458    -4.568 ***   1.006
                   Cyclobalanopsis gilva   2.708    -2.119 *     1.168
                   C longinux              2.681    -2.265 *     1.197
                   Zelkovaformosana         --         --         --
                   Schima superba          2.069    -9.000 ***   0.877
                   Fraxinus formosana      2.333    -5.397 ***   1.048
                   Swietenia mahogoni      2.014    -9.028 ***   0.927

(3) Rough          Cinnamomum camphora     3.306     2.2867 *    1.134
                   Machilus kusanoi         --         --         --
                   Actinodaphne            3.486     3.839 ***   1.075
                     nantoensis
                   Sasafras randaiense     3.361     2.654 *     1.154
                   Cassia siamea           4.000     7.994 ***   1.061
                   Scheffera actophylla    3.306     2.035 *     1.274
                   Cyclobalanopsis gilva    --         --         --
                   C longinux               --         --         --
                   Castanopsis carlesii    3.472     3.447 **    1.162
                     hay
                   Lithocarpus              --         --         --
                     amygdalifolius
                   Pasania brevicaudata    3.431     3.251 **    1.124
                   P. ternaticupula        3.722     5.757 ***   1.064
                   Trema orientalis        3.903     7.294 ***   1.050
                   Paulownia taiwaniana    3.831     6.811 ***   1.028

(4) Warm           Cinnamomun micranthum    --         --         --
                   Sasafras randaiense     2.736    -2.035 *     1.100
                   Acacia confuse          2.264    -5.676 ***   1.100
                   Cyclobalanopsis gilva   2.521    -3.138 **    1.286
                   C.longinux              2.306    -5.965 ***   0.988
                   Zelkova formosana       2.282    -5.795 ***   1.044
                   Schema superba          2.625    -2.644 *     1.204
                   Fraxinus formosane      2.528    -3.344 **    1.198
                   Swietenia mahogoni      1.917    -8.687 ***   1.058

(4) Cold           Michelia formosana       --         --         --
                   Trochodendron           3.431     3.053 **    1.197
                     aralioides
                   Machilus kusanoi        3.458     3.044 **    1.278
                   Actinodaphne            3.625     4.851 ***   1.093
                     nantoensis
                   Schefflera actophylla   3.583     3.848 ***   1.286
                   Castanopsis carlesii    3.389     2.527 *     1.306
                     hay
                   Pasania ternaticupula   3.319     2.142 *     1.265
                   Trema orientalis        3.319     2.592 *     1.046
                   Fraxinusformosane        --         --         --
                   Paulownia taiwaniana    3.443     3.646 ***   1.016

(5) Soft           Cinnamomun micranthum    --         --         --
                   Acacia confuse          2.444    -4.447 ***   1.060
                   Cyclobalanopsis         2.625    -2.753 **    1.156
                     longinux
                   Zelkova formosana       2.583    -3.149 **    1.123
                   Trema orientales         --         --         --
                   Schema superba          2.153    -6.078 ***   1.183
                   Fraxinus formosana      2.319    -5.522 ***   1.046
                   Swietenia mahogoni      2.097    -6.792 ***   1.128

(5) Hard           Michelia formosane       --         --         --
                   Trochodendron           3.361     2.524 *     1.214
                     aralioides
                   Machilus kusanoi         --         --         --
                   Actinodaphne            3.403     2.730 **    1.252
                     nantoensis
                   Cassia siamea           3.431     3.084 **    1.213
                   Cyclobalanopsis gilva    --         --         --
                   C.longinux               --         --         --
                   Lithocarpus              --         --         --
                     amygdalifolius
                   Pasania brevicaudata     --         --         --
                   P. ternaticupula        3.472     3.824 ***   1.048
                   Trema orientalis        3.389     2.765 **    1.193
                   Paulownia taiwaniana    3.451     3.395 **    1.119

(6) Natural        Michelia formosane      2.556    -2.904 **    1.299
                   Acacia confuse          2.458    -3.837 ***   1.198
                   Zelkova formosana        --         --         --
                   Trema orientales         --         --         --
                   Schema superba          2.222    -5.663 ***   1.165
                   Fraxinus formosane      2.681    -2.142 *     1.265
                   Swietenia mahogoni      2.292    -5.199 ***   1.156

(6) Artificial     Michelia formosane       --         --         --
                   Cyclobalanopsis gilva    --         --         --
                   C.longinux               --         --         --
                   Lithocarpus              --         --         --
                     amygdalifolius

                                                Radial section

(Group) Imagery    Species                 Mean    t value      SD

(1) Advanced       Cinnamomun micranthum   2.625   -2.813 **    1.131
                   Acacia confuse          2.611   -3.014 **    1.095
                   Cyclobalanopsis          --         --        --
                     longinux
                   Schima superba           --         --        --
                   Swietenia mahogoni      1.944   -8.670 ***   1.033

(1) Common         Michelia.formosana      3.417    3.017 **    1.172
                   Cinnamomum camphora     3.389    2.765 **    1.193
                   C. micranthum            --         --        --
                   Machilus kusanoi        3.764    6.393 ***   1.014
                   Actinodaphne            3.778    6.822 ***   0.967
                     nantoensis
                   Cassia siamea           3.528    4.388 ***   1.021
                   Schefffera actophylla   3.577    3.894 ***   1.250
                   Alnus formosana         3.347    2.736 **    1.077
                   Cyclobalanopsis         3.292    2.264 *     1.093
                     longinux
                   Castanopsis carlesii     --         --        --
                     hay
                   Pasania brevicaudata    3.278    2.187 *     1.078
                   P. ternaticupula         --         --        --
                   Trema orientales        3.278    2.112 *     1.116
                   Fraxinus formosana      3.347    2.612 *     1.128
                   Paulownia taiwaniana    3.375    3.149 **    1.013

(2) Elegant        Cinnamomun micranthum   2.625   -2.877 **    1.106
                   Acacia confuse          2.597   -3.318 **    1.030
                   Cyclobalanopsis gilva    --         --        --
                   C.longinux               --         --        --
                   Zelkovaformosana         --         --        --
                   Schima superba          2.667   -2.699 **    1.048
                   Fraxinus formosana       --         --        --
                   Swietenia mahogoni      1.986   -8.262 ***   1.041

(2) Meretricious   Michelia formosana      3.292    2.188 *     1.131
                   Cinnamomum camphora     3.306    2.454 *     1.057
                   Machilus kusanoi        3.556    4.504 ***   1.047
                   Actinodaphne            3.556    4.755 ***   0.991
                     nantoensis
                   Cassia siamea           3.472    4.096 ***   0.978
                   Schefera actophylla     3.394    2.664 *     1.248
                   Cyclobalanopsis         3.389    2.638 *     1.251
                     longinux
                   Castanopsis carlesii     --         --        --
                     hay
                   Pasania ternaticupula   3.292    2.164 *     1.144
                   Trema orientalis         --         --        --
                   Paulownia taiwaniana     --         --        --

(3) Exquisite      Cinnamomun micranthum   2.569   -3.326 **    1.098
                   Acacia confuse          2.556   -3.979 ***   0.948
                   Cyclobalanopsis gilva    --         --        --
                   C longinux               --         --        --
                   Zelkovaformosana        2.681   -2.106 ***   1.287
                   Schima superba          2.423   -4.170 ***   1.167
                   Fraxinus formosana      -                    -
                   Swietenia mahogoni      2.056   -7.378 ***   1.086

(3) Rough          Cinnamomum camphora      --         --        --
                   Machilus kusanoi        3.417    3.260 **    1.084
                   Actinodaphne            3.639    4.799 ***   1.130
                     nantoensis
                   Sasafras randaiense      --         --        --
                   Cassia siamea           3.528    4.274 ***   1.048
                   Scheffera actophylla    3.423    3.263 **    1.091
                   Cyclobalanopsis gilva   3.403    2.513 *     1.360
                   C longinux              3.333    2.408 *     1.175
                   Castanopsis carlesii     --         --        --
                     hay
                   Lithocarpus             3.444    2.979 **    1.266
                     amygdalifolius
                   Pasania brevicaudata     --         --        --
                   P. ternaticupula        3.333    2.632 *     1.075
                   Trema orientalis         --         --        --
                   Paulownia taiwaniana     --         --        --

(4) Warm           Cinnamomun micranthum   2.583   -3.260 **    1.084
                   Sasafras randaiense      --         --        --
                   Acacia confuse          2.569   -3.251 **    1.124
                   Cyclobalanopsis gilva    --         --        --
                   C.longinux               --         --        --
                   Zelkova formosana       1.986   -8.992 ***   0.957
                   Schema superba          2.653   -2.704 **    1.090
                   Fraxinus formosane       --         --        --
                   Swietenia mahogoni      1.833   -9.212 ***   1.075

(4) Cold           Michelia formosana      3.347    2.504 *     1.177
                   Trochodendron            --         --        --
                     aralioides
                   Machilus kusanoi        3.625    4.588 ***   1.156
                   Actinodaphne            3.458    3.622 ***   1.074
                     nantoensis
                   Schefflera actophylla   3.507    3.732 ***   1.145
                   Castanopsis carlesii     --         --        --
                     hay
                   Pasania ternaticupula    --         --        --
                   Trema orientalis         --         --        --
                   Fraxinusformosane       3.264    2.084 *     1.075
                   Paulownia taiwaniana    -

(5) Soft           Cinnamomun micranthum   2.625   -2.877 **    1.106
                   Acacia confuse           --         --        --
                   Cyclobalanopsis          --         --        --
                     longinux
                   Zelkova formosana       2.486   -3.790 ***   1.151
                   Trema orientales        2.486   -4.331 ***   1.007
                   Schema superba          2.639   -2.433 *     1.259
                   Fraxinus formosana       --         --        --
                   Swietenia mahogoni      1.986   -8.055 ***   1.068

(5) Hard           Michelia formosane      3.403    2.730 **    1.252
                   Trochodendron            --         --        --
                     aralioides
                   Machilus kusanoi        3.417    2.900 **    1.219
                   Actinodaphne            3.542    4.179 ***   1.100
                     nantoensis
                   Cassia siamea            --         --        --
                   Cyclobalanopsis gilva   3.472    3.058 **    1.251
                   C.longinux              3.514    4.108 ***   1.184
                   Lithocarpus             3.458    3.667 ***   1.061
                     amygdalifolius
                   Pasania brevicaudata    3.458    3.578 ***   1.087
                   P. ternaticupula        3.514    4.523 ***   1.047
                   Trema orientalis         --         --        --
                   Paulownia taiwaniana     --         --        --

(6) Natural        Michelia formosane       --         --        --
                   Acacia confuse          2.486   -4.009 ***   1.088
                   Zelkova formosana       2.583   -2.703 **    1.308
                   Trema orientales        2.292   -5.497 ***   1.093
                   Schema superba          2.528   -3.600 ***   1.113
                   Fraxinus formosane       --         --        --
                   Swietenia mahogoni      2.167   -5.843 ***   1.210

(6) Artificial     Michelia formosane      3.375    2.724 **    1.168
                   Cyclobalanopsis gilva   3.361    2.063 *     1.485
                   C.longinux              3.514    3.383 **    1.289
                   Lithocarpus             3.375    2.594 *     1.227
                     amygdalifolius

a * = P <0.05; ** = P <0.01; *** = P <0.001.

Table 4.--Correlation analysis of color and each image.

                                         Color coefficient (a)

Adjectives and their counterparts   [L.sup.*]   [a.sup.*]   [L.sup.*]

Advanced [left and right arrow]     -0.468 **   0.665 **      0.006
  common
Elegant [left and right arrow]      -0.392 **   0.710 **      0.113
  meretricious
Exquisite [left and right arrow]     0.205      0.696 **      0.275
  rough
Warm [left and right arrow] cold    -0.593 **   0.678 **      0.124
Soft [left and right arrow] hard     0.046      0.694 **      0.358
Natural [left and right arrow]       0.403      0.433         0.367
artificial

(a) ** = P <0.01.

Table 5.--Correlation analysis of grains and each image.

                                            Grain coefficient (a)
Adjectives

and their                                Growth
counterparts                              ring     Section    Rays

Advanced [left and right arrow] common    0.255     -0.079   0.304
Elegant [left and right arrow]            0.211     -0.016   0.127
 meretricious
Exquisite [left and right arrow] rough    0.223     -0.044   0.268
Warm [left and right arrow] cold          0.087      0.000   0.183
Soft [left and right arrow] hard          0.363     -0.116   0.435 *
Natural [left and right arrow]            0.471     -0.471   0.826 **
 artificial

(a) * = P <0.05; ** = P < 0.01.
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Author:Chen, Tien-li
Publication:Forest Products Journal
Geographic Code:9TAIW
Date:Jan 1, 2012
Words:6074
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