• Journal of Industrial Convergence
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• v.13 no.1
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• pp.41-47
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• 2015

The purpose of this study was to investigate how environment-friendly activities through nature affects attitude of children. 5-6 years old children were targeted for study from March to December, 2014. Rapid changes of modern society made increase of female workers and their participation rates in economic activity which results children to play more time with artificial toys and media. There are 3 stages to investigate effects. $1^{st}$ stage is to know about woods by visiting woods and experience environment-friendly activity. $2^{nd}$ stage is to experience woods with 5 senses not only in real woods but also in classroom. Lastly $3^{rd}$ stage is to make art work with natural object and make woods in classroom. Changes of hildren's attitude and view toward to the nature were recorded and analyzed by anecdotes perpetual inventory and environment-friendly attitude examination. By analysis of infant gives you the opportunity to encounter nature, often in conjunction with ongoing enjoys nature-friendly program in the classroom to play with toys, rather than a complete natural objects gradually formalized when presenting a natural, concentrated than the previous game this time is enhanced and creativity through nature through the promotion doeeojim and attitude to nature is also eco-friendly activities byeonhwadoem program showed that the impact on the attitude of the infant.

• Journal of Korean Society of Forest Science
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• v.2 no.1
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• pp.37-40
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• 1962

1) The greater parts of rail road cross tie wood in Korea have been supplied by the imported woods from foreign countries such as Formosa (Taiwan) and Japan. However on account of anatomical properties on these imported woods are not known when newly imported, identification and preservative treatment are apt to fail. Accordingly this expriment was accomplished by the need of application of anatomical properties for the preservative treatment and identification of several imported woods. 2) In this study macroscopical and microscopical properties were inspected and briefly described about four species (Cyclobalanopsis gilva Blume, Castanopsis longicaudata K. et H., Machilus longiflora Hay and Schima superba Gard et Champ) from Formosa and one (Fagus crenata, Blume) from Japan. With several native species these are important as the rail road tie wood in Korea. 3) According to the results measured values of the vessels and fibers of each tested species are as following table.

• Journal of the Korea Furniture Society
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• v.18 no.1
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• pp.20-30
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• 2007

This experiment was carried out to investigate the effects of number and location of finger joints on the bending strength of glue-laminated lumbers. Urea resin adhesives were used in this experiment and the resin content was 70% for cold pressing. The lamina were edge-jointed and end-jointed. The specimen were composed of one or three layers. The obtained results are summarized as follows; The effects of finger joints on the decrease of bending strength of glue laminated woods were different according to the number and location of finger joints. The decrease of MOR was highest on the middle position of laminated woods. The effects of several arrangements of finger joints on the bending strength of glue laminated woods showed on Figure 7 and 8. The variance of thickness-laminating on the bending strength of glue laminated woods were larger than those of width-laminating.

• Journal of Industrial Technology
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• v.19
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• pp.361-368
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• 1999

The Nelder-Mead simplex algorithm has become on of the most widely used methods for nonlinear unconstrained optimization, since 1965. Recently, this algorithm has been reevaluated and many papers on this algorithm are being published. The MATLAB computer software, highly renown in engineering, also provides the Nelder-Mead algorithm and the Denis-Woods modification with FMINS function. The authors made C++ code of these algorithms and compared with FMINS on the convergence behavior and the exactness of solutions. It shows that MATLAB's FMINS is inferior to author's C++ code. So, FMINS should be corrected for every user.

• Journal of the Korea Furniture Society
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• v.22 no.2
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• pp.126-131
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• 2011

The purpose of this study were to analyze the species and tree-ring dates of coffin woods excavated at Yerim site in Yesan, Chungnam, Korea. We sampled 12 pieces of woods from two coffins. The species of all coffin woods were identified as red pine group, most likely, $Pinus$ $densiflora$. The last rings of both coffins were dated A.D. 1557 and A.D. 1601, respectively. The tree-ring dates indicated that the coffins were made in the late 16th and early 17th century.

• Journal of the Korean Wood Science and Technology
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• v.17 no.2
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• pp.1-12
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• 1989

To study the structure of opposite wood in the angiosperms. samples were cut from stems and branchs of 10 spcies growing in Korea. The opposite side was defined as being along a line passing from the most wide annual ring of the tension wood on the upper side to the pith and extrapolated through the opposite side. lateral sides being on the right and left of this line. The stem woods growing almost horizontally were surveyed the structural features of the well-developed opposite wood for the tension wood. In the annual-ring of the well-developed opposite woods. an investigation was made on how the dimension of elements, microfibril angles. and cell wall layers change from tension side to opposite side. The structural characteristics of opposite wood in hardwoods realized in this study are as follows: 1. The vessel diameters increased continuously to ward the opposite side in which the values were maximum. The vessel length also increased toward opposite side. but the rates of increase were smaller than those in the vessel diameters. 2. The wood fiber length were decreased from tension toward opposite side. but the rates of decrement were f1actuated within the sampled species. 3. The microfibril angles had the minimum values on the tension side. then increased steeply toward the opposite side in which the values maximum. 4. In the percentage of elements the vessel elements increased continously at a relative rate from the tension to opposite side, whereas the values of the wood fibers were lower in the opposite than the tension side, but the' variation patterns of rays were not seem distinctly. 5. The component layers of the wood fiber in the opposite woods were very similar to the lateral woods.

• Journal of the Korean earth science society
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• v.31 no.6
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• pp.573-583
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• 2010

A paleobotanical study of the fossil woods has been carried out from the Tertiary Janggi Group, Pohang Basin. Three species belonging to three genera of Ulmus sp., Prunus sp., and Acer sp. were identified from the Lower Coalbearing Formation, and two species of two genera of Taxodioxylon sp. and Fagus hondoensis (Watari) from the Upper Coal-bearing Formation. As our specimens are mostly poorly preserved, it is difficult to give clear specific names, but mostly are all characteristic constitutional elements of the Miocene fossil woods in Korea. The values of mean sensitivity measured from the fossil woods of Lower and Upper Coal-bearing Formations are 0.367 and 0.370 respectively, but they are more than 0.30. Based on the present two data mentioned above, it stands to reason that there were many changes in the water supply to the roots of the woods or having influence to some degree each year because of the seasonal changes in rainfall.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.689-702
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• 2017

In this study, with the view to using effectively small and medium diameter Korean domestic woods as structural materials, cross-laminated woods were manufactured by using six species of Korean domestic softwoods and hardwoods, and bending creep properties were investigated for each species. The creep curves showed the shape of the exponential function plot, and the creep curves after 1 hour were able to estimate by fitting it to the power law. The initial and creep compliances of cross-laminated woods showed the higher values in wood species with a low density than in that with a high density. And by cross-laminating, the initial and creep compliances perpendicular to the grain considerably decreased, the extent of the decrease was found to be greater in creep deformation than in initial deformation. The creep anisotropies of cross-laminated woods were considerably decreased by cross-laminating. The relative creep of $C_{\bot}$ type composed of perpendicular-direction lamina in the faces decreased 0.59 - 0.64 times compared to that of $P_{\bot}$ type composed of perpendicular-direction laminae in all layers, and that for $C_{\parallel}$ type composed of parallel-direction laminae in the faces increased 1.5 - 1.6 times compared to that of $P_{\parallel}$ type composed of parallel-direction laminae in all layers.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.8-15
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• 2003

This study was carried out to investigate the dimensional stability of wood treated with PEG for better utilization of domestic small-diameter logs. Four species of ring- porous wood(Quercus mongolica F_ISCH, Quercus variabilis B_LUME, Fraxinus rhynchophylla H_ANCE, Paulownia coreana U_YEKI,) and four species of diffuse-porous wood(Prunus sargentii R_EHDER, Betula davurica P_ALL, Populus tomentiglandulosa T. L_EE, Cornus controversa H_EMSLEY) were used for this experiment. The shrinkage of wood decreased with increasing the concentration of PEG. The shrinkage of diffuse- porous woods was lower than that of ring-porous woods. The weight gain increased in proportional to the PEG concentration. Diffuse-porous woods showed a little higher weight gain than ring-porous woods. Bulking effect also increased with increasing the PEG concentration, but was in inverse proportional to the molecular weight of PEG. Diffuse-porous woods showed higher bulking effect than ring-porous woods. Consequently, diffuse-porous woods showed better dimensional stability than ring- porous woods. It was considered that dimensional stability was affected by characteristics of wood such as vessel and tylosis, and density.

• Journal of the Korea Furniture Society
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• v.12 no.2
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• pp.19-27
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• 2001

This study was carried out to investigate the mechanical properties of woods treated with 30% aqueous solution of PEG 1000. Compressive, bending and shearing strengths were slightly decreased by PEG treatment. Absorbed energy in impact bending did not show any significant differences between untreated and PEG-treated woods.