• Journal of the Korean Wood Science and Technology
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• v.36 no.5
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• pp.33-41
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• 2008

This study was aimed to develop the knot quantification method to predict bending strength, using x-ray scanner. The bending strength prediction model was proposed in this paper. The model was based on Knot Depth Ratio (KDR) and closely-spaced knot was taken into account. The previous paper reported that KDR is the ratio of the knot and transit zone to the lumber thickness. Even though KDR involves transit zone, it was verified that the ratio of the moment of inertia for knot to gross cross section ($I_k/I_g$) based on KDR was a good predictor for bending strength of lumber. To take closely-spaced knot into account, a projection method was also proposed. This projection method improved the predictive accuracy significantly. It showed coefficient of determinant of 0.65 and root mean square error (RMSE) of 9.17.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2797-2804
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• 1994

This paper analyzes the behaviors of corrugated membrane under the cryogenic liquid pressure and thermal loading using the FEM analysis program MARC. The FEM calculations were carried out on the basis of measured data of Technigaz membrane. It is very important to know the concentration levels and distributions of stress in the corrugated membrane. A quarter of the membrane sheet in place of the whole membrane was simulated because of its geometric symmetricity. The calculated results of the concentrated stress showed that the maximum stress occurs at the knot parts and at the root corner radius of the corrugations. The FEM calculated results indicated that the ring knot membrane which was developed in this study showed uniformly distributed stress and the lowest stress levels in the cross knot area in comparison with other two membranes. These results are very important to optimize the shape and improve the safety of membrane structure.

• Journal of the Korean Wood Science and Technology
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• v.31 no.2
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• pp.16-23
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• 2003

The study was performed to obtain basic data for high quality timber production and efficient utilization of woods by investigating the effects of thinning on timber quality of domestic Korean pine(Pinus koraiensis Sieb. et Zucc.) planted. The results of this study were summarized as follows ; Comparing the appearance of knot per one meter on log surface, the heavy thinned trees contained less knots than non-thinned ones. And the ratio of dead knots was decreased in heavy thinned trees compared with the non-thinned ones, but the knot size was increased. The inclination angle of dead knot is larger than that of live knot. The crooked logs in heavy thinning plot appeared less than those in non-thinning plot. In heavy thinning plot, the log circle percentage of cross section and the ratio of clear lumber were increased, compared with in non-thinning one. The grade of log was the highest in heavy thinning plot.

• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.141-148
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• 2013

The goal of this study was to find the optimum lamina size from red pine (Pinus densiflora) and Japanese cedar (Cryptomeria japonica) logs for the cross laminated timber (CLT) production. From visual inspection of the logs from two species, red pine log showed a larger knot and warp compared to the Japanese cedar. Different cross-sectional sizes of lamina ($110mm{\times}30mm$, $110mm{\times}40mm$, $110mm{\times}50mm$, $50mm{\times}30mm$, $30mm{\times}30mm$) from two species were analyzed for yield and grade. Regardless of the species, the optimized cross sectional size for maximizing the yield was $110mm{\times}30mm$. In grading for the different size laminas from Japanese cedar and red pine, a higher percentage of the first and second grade was found from the $110mm{\times}30mm$ lamina cut.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.91-100
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• 2008

Melting curve analysis of fluorescently labeled DNA fragments is used extensively for genotyping single nucleotide polymorphism(SNP). Here, we evaluated a SNP genotyping method by melting curve analysis with the two probe chemistries in a 384-well plate format on a Roche LightCycler 480. The HybProbe chemistry is based on the fluorescence resonance energy transfer(FRET) and the SimpleProbe chemistry uses a terminal self-quenching fluorophore. We evaluated FRET HybProbes and SimpleProbes for two SNP sites closely linked to two quantitative trait loci(QTL) for southern root-knot nematode resistance. These probes were used to genotype the two parents and 94 $F_2$ plants from the cross of PI 96354$\times$Bossier. The SNP genotypes of all samples determined by the LightCycler software agreed with previously determined SSR genotypes and the SNP genotypes determined on a Luminex 100 flow cytometry instrument. Multiplexed HybProbes for the two SNPs showed a 98.4% success rate and 100% concordance between repeats two of the same 96 DNA samples. Also, we developed a HybProbe assay for the Rcs3 gene conditioning broad resistance to the frogeye leaf spot(FLS) disease. The LightCycler 480 provides rapid PCR on 384-well plate and allows simultaneous amplification and analysis in approximately 2 hours without any additional steps after amplification. This allowed for a reduction of the potential contamination of PCR products, simplicity, and enablement of a streamlined workflow. The melting curve analysis on the LightCycler 480 provided high-throughput and rapid SNP genotyping and appears highly effective for marker-assisted selection in soybean.

• Journal of the Korean Wood Science and Technology
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• v.34 no.2
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• pp.1-9
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• 2006

The structural wooden members of the ancient building are deteriorated by fungi and termite over time. The deteriorate of the members causes the decrease of the specific gravity and the strength of it, so the stability of the building is threatened. Therefore, in this study, the evaluation of the specific gravity, which is correlated with the strength of the wood, was conducted in the post member using Nondestructive Evaluation (NDE) - Drilling Resistance Test (DRT). For the purpose of it, the specific gravity and drilling resistance of small specimens was measured to obtain the correlation between the specific gravity and the drilling resistance. And then, the drilling resistance test of the post members, which were expected to have the deteriorated parts, was performed. Consequently, the correlation between the specific gravity and the drilling resistance was very high ($R^2=0.89$) and the distributions of the specific gravity were evaluated for the each member. Also, the results were verified by the visual inspection of the cross section of it. Especially, the various variations of the wood member such as the deteriorated parts with termite or fungi and the crack could be detected exactly but the knot couldn't because the drill could pass by or could not penetrate the knot.

• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.47-54
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• 1995

This study was to measure the properties of logs and classify them by non-destructive methods. The purpose of this experiment was focused at mensurability of logs by non-destructive methods. The non-destructive instrument, Stress-Wave Timer 239A which was made by Metriguard in U.S.A., was used. The stress wave velocities of log's cross direction were measured and compared with three different methods; 1. with hammer, 2. with hammer and D.B.H. meter, 3. with manufactured instrument. Number of used logs were seven logs, which were classified by naked eye into six groups; very severe rot, severe rot, mild rot & knot, mild rot & check, mild rot, sound log, and in diameter were into three groups; large(57.4cm), medium(36~41.2cm), small(28.9cm) log. The results, which were classified by mensurability with non-destructive methods, were followed; 1. The stress wave velocities were very different between rot and sound log. So it meant the possibility of mensurability of logs by non-destructive method even if high standard error. 2. The stress wave velocities decreased with checks more than with rots, which meant the checks affected speeds more. 3. The stress wave velocities increased with knot. 4. The velocities with manufactured instrument showed lower standard error, so more accurate results than other methods. Especially the required labour decreased from 3~4 to 2 persons. 5. Finally, the mensurability showed more accurate results and made the classification of logs scientific.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.4
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• pp.389-397
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• 1997

In this paper, we propose a new method of contour error modeling for cross-coupled control of CNC machines. This modeling method is based on the information that the interpolator of a CNC machine generates knot points per each sampling time in order to approximate a given curved path as a series of small straight-line segments. The merits of the proposed method are : (1) its applicability for arbitrary curved contours and (2) its ability to calculate contour errors more accurately than the other conventional methods. The proposed method is evaluated and compared with the conventional methods using the three typical curved trajectories by computer simulations. Furthermore, it is shown that the cross-coupled controller based on this proposed error model improves contouring accuracy more effectively than the other methods.

• Journal of the Korean Society of Costume
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• v.37
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• pp.149-162
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• 1998

This study is thed Embroidery, Cross-stitchery, Weaving, Wax-Printing of technique and design appeared in textile of Miaos dwells in south-west among the minority people of china. The study is as follows. First, the technique of textile1) satin stitch, couching stitch, french-knot stitch, etc. using anther silk thread or cotton thread color 2) cross-stitchery 3) hand-weaving technique which is shaped other warp or weft using simple loom 4) the technique of dyeing of pattern using effect with wax. These methods are singly used mixing together, therefore doubled beauty. Second, these technuque of ornament have other independence, specially ornament apron, sling, sleeve borders, slack borderss, edge of upper garment, take off and put on easily, heighten effect of various ornament, can preserve many years. Third, Maker, female born in this country fashion by need of herself, used liberal method shown in unique creativity of life. This texture make standards capable female proud of intelligent and skill of herself. Fourth, Design appeared in textile like as pattern flying bird in the sky, strolling beast in the field, lion rolling gem, laughing dragon winding snake at gem, birks, flowers, fish, butterfly is used as the wish of long life, a lucky sign. They expressed creativity and unique conception using formation : the technique transform other shape using by omitting or adding or overestimating. Geometric pattern of tartan, revealing, Fifth, composition structure having balance and symmetry or contradiction towards center and circumstance of the center harmonized repeatedly method, expressed unique artful attraction by full composition.

• Journal of the Korean Society of Costume
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• v.58 no.8
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• pp.120-136
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• 2008

This study examined sewing methods used to reinforce the opening of clothes of the Joseon period. Through the analysis of a total of 117 clothing items of the Joseon period, the following results were obtained. 1. Most costumes of the Joseon period had the opening. The purpose of the opening was to allow one to put on and take off a costume, act comfortably, and turn a costume Inside out. The opening was located on the Side, Conte. Back, fgwi(Side opening of pants), Wristband, Armhole, and Godae(the bark part of the collar). 2. As the opening tended to get easily worn out, it was often reinforced. The 1911owing three methods were used to reinforce the opening of clothing items of the Joseon period: a method to attach a cloth such as Dang, Binding, and Badae; a method using a variety of knots; and a method by sewing stitches such as a sort of cross stitch called Satteugi, Prick stitch, and Loop. 3. The most frequently used reinforcing method was the one that used a knot(34 items), followed by the one by sewing Satteugi(27 items), and the one using Dang(25items). The most frequently detected location of the opening was Side(59 items), followed by Agui(37 items), Wristband(19 items), and Center Back(13 items). 4. The reinforced opening made a costume more endurable and elastic, decorative and neat.