• Journal of the Korea Furniture Society
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• v.23 no.1
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• pp.57-67
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• 2012

Recently, shows the possibility of providing such dyed-gathered woods after forming single boar This studyds with using cheap timbers generated by the thinning. It is helpful for master artisans are suffering from finding qualified materials. Traditionally, the master artisan has been used the beautiful grained wood from around roots of old zelkova trees and black persimmon trees. Instead, this study shows that dyed-gathered woods replace the natural grained wood and also produces a furniture made of an aggregate and a plate from walnut trees and ash trees which are a contrast to dyed-gathered woods. Dyed-gathered woods can reproduce the various colors to satisfy people's tastes, and the dignified grains that we can see in the old woods. Besides, dyed-gathered woods can replace rare materials and provide higher reliability of supplies.

• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.290-300
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• 2014

In this study, cross-laminated woods were made with spruce wood and the effects of annual ring angles of perpendicular direction laminae on static bending strength performance were investigated. Static bending strength performances of parallel laminated woods with all layers composed of laminae perpendicular to the grain ($P_{\bot}$ type) were in the order of $90^{\circ}$ > $0^{\circ}$ > $45^{\circ}$. The MOE and MOR for the $45^{\circ}$ annual ring angle were 0.0989 GPa and 3.25 MPa, and it showed the lowest values. By placing longitudinal-direction laminae in the core of $P_{\bot}$ type, the strength performances were markedly improved. In the case of cross-laminated woods with perpendicular-direction laminae in the faces ($C_{\bot}$ type), the bending strength performances were in the order of $90^{\circ}$ > $0^{\circ}$ > $45^{\circ}$, but the differences among annual ring angles were less than those of the parallel-laminated woods. In the case of cross-laminated woods with perpendicular-direction laminae in the core ($C_{\parallel}$ type), the bending strength performances were in the order of $45^{\circ}$ > $90^{\circ}$ > $0^{\circ}$ unlike $P_{\bot}$ type and $C_{\bot}$ type. The MOE and MOR for the $45^{\circ}$ annual ring angle were 12.0 GPa and 55.8 MPa, and it showed the highest values.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.449-456
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• 2016

This study was aimed to quantify the amount of carbon dioxide emissions and to suggest suitable plans which consider the carbon emission reduction in the manufacturing process of the domestic structural glued laminated timber. Field investigation on two glued laminated timber manufacturers was conducted to find out material flow input values such as raw materials, transportation, manufacturing process, and energy consumption during manufacturing process. Based on the collected data and the relevant literatures about life cycle inventory (LCI), the amount of carbon dioxide emission per unit volume was quantified. Results show that the carbon dioxide emissions for sawing, drying and laminating process are 31.0, 109.0, 94.2 kg $CO_2eq./m^3$, respectively. These results show 13% lesser amount of total carbon dioxide emissions compared with the imported glued laminated timber in Korea. Furthermore, it was decreased about 37% when the fossil fuel would be replaced with biomass fuel in drying process. Findings from this study is effectively used as the basic data on the life cycle assessment of wooden building.

• Journal of Korean Association for Spatial Structures
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• v.20 no.2
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• pp.39-49
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• 2020

In this study, we will develop a hybrid cross-sectional shape of steel inserted type glued-laminated timber that can improve the strength of structural glued-laminated timber and maximize the ductility by using steel plate with excellent tensile and deformation ability. A total of three specimens were fabricated and the flexural performance test was carried out to evaluate the structural performance of the steel inserted type glued-laminated timber. In order to compare the effect of steel inserted glued-laminated timber, one structural glued-laminated timber test specimen composed of pure wood was manufactured. In addition, in order to evaluate the adhesion performance of the steel inserted, one each of a screw joint test specimen and a polyurethane joint test specimen was prepared. As a result, all the specimens showed the initial crack in the finger joint near the force point. This has been shown to be a cause of crack diffusion and strength degradation. The use of finger joints in the maximum moment section is considered to affect the strength and ductility of the glued-laminated timber beam. Polyurethane-adhesive steel inserted glued-laminated timber showed fully-composite behavior with little horizontal separation between the steel plate and glued-laminated timber until the maximum load was reached. This method has been shown to exhibit sufficient retention bending performance.

• Journal of the Korean Wood Science and Technology
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• v.49 no.4
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• pp.336-359
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• 2021

In this study, hybrid CLT research and development trends were analyzed to improve the low rolling shear strength of CLT, a large wooden panel used in high-rise wooden buildings. Through this, basic data that can be used in research and development directions for localization of CLT were prepared. As a way to improve the low rolling shear strength, the use of hardwood lamina, the change of the lamina arrangement angle, and the use of structural composite materials are mainly used. Rolling shear strength and shear modulus of hardwood lamina are more than twice as high as softwood lamina. It confirmed that hardwoods can be used and unused species can be used. Rolling shear strength 1.5 times, shear modulus 8.3 times, bending stiffness 4.1 times improved according to the change of the layer arrangement angle, and the CLT strength was confirmed by reducing the layer arrangement angle. Structural wood-based materials have been improved by up to 1.35 times MOR, 1.5 times MOE, and 1.59 times rolling shear strength when used as laminas. Block shear strength between the layer materials was also secured by 7.0 N/mm², which is the standard for block shear strength. Through the results of previous studies, it was confirmed that the strength performance was improved when a structural wood based materials having a flexural performance of MOE 7.0 GPa and MOR 40.0 MPa or more was used. This was determined based on the strength of layered materials in structural wood-based materials. The optimal method for improving rolling shear strength is judged to be the most advantageous application of structural wood based materials with strength values according to existing specifications. However, additional research is needed on the orientation of CLT lamina arrangement according to the fiber arrangement of structural wood-based materials, and the block shear strength between lamina materials.

• Journal of the Korea Furniture Society
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• v.13 no.1
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• pp.9-17
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• 2002

Laminated lumber is an engineered wood products using stress rated, seasoned and selected lumber. Each piece of lumber is graded, and then end jointed to produce the required length. This study was carried out to investigate the possibility of wooden artifacts with laminated lumber. It is expected through this research that wooden artifacts, which have originality and local character, can be developed by making design of wooden artifacts through the use of plentiful resources around the local area. A development of new design products, an improvement of distributive structure and the achievement of international competitiveness will contribute to develop the industrial artifacts art in Korea. And, it is necessary to develop a corporation system between industrial craft companies and universities.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.617-621
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• 2016

On-site survey on glue-laminated board (GLB) manufacturers of Malaysia, Indonesia, and China was conducted to identify the cause of interception of regulated pest from imported GLBs from those countries, and to suggest optimal manufacturing processes of GLB for preventing quarantine risk associated with imported GLBs. The cause of pest interception was improper manufacturing processes, such as air drying or inadequate kiln drying of green laminae, improper storage of dried laminae before finger jointing and edge gluing, and/or incomplete packing of GLBs. In particular, Paulownia GLB manufacturing processes used in China, including air drying of laminae, were mostly poor in terms of preventing quarantine risk associated with imported GLBs. From now on, for preventing quarantine risk associated with imported GLBs, importers have to ask foreign manufacturers spontaneously to use proper manufacturing processes (adequate kiln drying of green laminae, proper storage of dried laminae, and complete packaging of final GLBs).

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.828-835
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• 2017

Airtightness of buildings is one of critical aspects of its energy performance. To build up references of airtightness of wooden houses built in Korea, blower door tests have been carried out in 42 houses since 2006. Causes of air leakage were investigated recently. The average value of air change rate was $3.7h^{-1}$ for light frame house and $5.5h^{-1}$ for post-beam construction at ACH50 (air change per hour at 50 Pa air pressure difference). Foam type insulation was more advantageous in ensuring building airtightness than glass fiber batt. Airtightness of wooden houses which were constructed after 2010 was improved to have less than $1.5h^{-1}$ of ACH50, threshold for application of artificial air change. The average air change rate of CLT (cross laminated timber) houses showed the lowest value, $1.1h^{-1}$, among the tested structures.

• Journal of the Korea Furniture Society
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• v.25 no.4
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• pp.345-352
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• 2014

This study was carried out to develop eco-friendly wood street lamp (EFWSL) by using wood resources stacked in the forests after tree tending operations which were mostly abandoned, but economical as renewable wood resources for developing the wood coated street lamps with the effects of cost reduction and their attractive appearances. This study has led to the development of key compact structures of street-lighting wood poles (shaft) using laminated timber. The core technique in this study is related with producing the more stable wood poles (shaft) with the hole inside than wood poles exposed under the natural environment through applicable process to protect the wood from bursting and splitting. We also comprehensively developed the method to conserve the timber durability of wood shaft and connect the wood shaft with groove, race way to be located in the groove, locking ring, current stabilizer connected to the groove and luminaire support arm, base and hand-hole which was partly used in combination with steel materials and wood. Also we increased the utilization of abandoned and stacked woods after thinning in the forests such as Pinus densiflora, Larix leptolepis, and Pinus koraiensis plantations by maximizing the value of these natural wood resources as main materials of eco-friendly street lightings with the effects of cost reduction and attractive appearances and also the expectation of advertising effects of street lightings developed in this study.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.4
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• pp.225-233
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• 2018

One of engineered woods, glued laminated timber (GLT), can provide a constant level of performance and desired strength even if the quality of wood is low. Due to this fact, there is a growing interest in GLT using domestic species and related research has been carried out continuously. In addition, GLT is popularly being applied to the long-span or high-rise structures overseas. However, KBC 2016 does not allow the engineered woods to be used for middle and high-rise buildings by limiting height. Therefore, a proper design procedure and rationale should be clearly presented by the help of performance-based seismic design. With this background, the goal of this study is to establish a specific procedure for design of a 9-story building with RC shear walls and GLT frames according to the performance-based design of KBC 2016. The performance objectives were set according to KBC and the acceptance criteria for each goal were defined. The RC shear walls and GLT frames were designed by concrete and wood structure requirements, respectively. Analytical models were developed to reflect their nonlinear features, and both nonlinear static and dynamic analyses were conducted. Performance evaluation results showed that the shear walls have insufficient shear strength, so they were re-designed. Consequently, it has been confirmed that GLT frames can be applied to a 9-story office building with the assistance of RC shear walls and performance-based seismic design.