• Journal of the Korean Wood Science and Technology
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• v.46 no.6
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• pp.726-734
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• 2018

In this study, for using effectively domestic (temperate) small and medium diameter logs as a wooden floorboard, cross-laminated wood panels were manufactured using domestic larch and tulip woods as a base material for teak and merbau wood flooring, and static bending strength performances were measured to investigate the applicability as the base materials of wooden flooring in place of plywood. Static bending MOE was much influenced by the strength performances of the top layer lamina than that of the laminae for base materials. Bending MOR showed the higher values in tulip wood that was hardwoods than in larch wood that was softwoods regardless of the strength performances of the top layer laminae, and it was found that the values were much influenced by the strength performances of the base materials used in the core and bottom layers. However these values were 1.4-2.5 times higher values than the bending strength of the wooden floorboards specified in KS, it was found that it can be sufficiently applied to the base materials of wooden floorboards in place of plywood.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.235-239
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• 2004

Sound transmission either as airborne or structure borne is a potential problem that occurs in buildings either from sources within or from outside. With the expansion of real estate activities in countries like India, the need to attend sound insulation requirements also assumes greater dimensions. The focus of this research is on studying the sound transmission characteristics of building structures made of hollow blocks, neocrete block, aerocon block and prefabricated panels such as Ferrocement panel. The tests were carried out the blocks with and without plastering and their sound reduction index was measured at one-third octave frequencies. In the case of ferrocement panels, different types of systems were tested in the TL suite. Panels with cavity, with cavity ties, with insulation, with stiffeners and with plasterboard were investigated. Sound reduction index of these panels was measured with additional quantities like longitudinal wavespeed, and loss factors (internal and total loss factor). Tests were also conducted on Cypcrete wall panel and Sandwiched wooden panel in a similar way. Theoretical investigations were carried out using Statistical Energy Analysis (SEA) for the above systems. Sound reduction index was then compared between the predicted and the measured values.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.65-71
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• 2001

Absorbers such as porous materials and panels have limited absorption characteristics to some frequency bands. There is a need for absorbers with high absorption coefficients in a wide frequency ranges to make good response of room acoustics. This is almost impossible for a single absorption material. Composite absorption structure with cover, porous material. and air gap is known to have those wide frequency characteristics. In this basis. various composite absorption structures are measured and investigated as wide range absorption structures. Measurements are performed according to an international standard, ISO 354. Various surface types such as wooden slits, wood/steel perforated panels are selected as surface covers, and also various porous materials such as polyurethanes, polyesters, and glasswools are used inside the covers. Result shows that the area of void parts of surface materials is critical to high frequency absorptions, and thickness of air gaps are critical factor of the peak absorptions of low frequency bands.

• Journal of the Korea Furniture Society
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• v.21 no.6
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• pp.449-458
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• 2010

This study attempted to investigate the effect of panel thickness on the horizontal density distribution (HDD) of medium density fiberboard (MDF) in a destructive way. Full size MDF panels with five different thicknesses such as 2 mm, 4.5 mm, 9 mm, 18 mm and 30 mm were cut into two different specimen sizes, i.e., $500{\times}500\;mm$ and $120{\times}120\;mm$ to measure the HDD. In general, the overall density of MDF panel diminished as the thickness increased, showing the highest density for the thinnest MDF panels. The HDD variation was significant for the samples of smaller specimen size ($120{\times}120\;mm$). MDF panel thickness significantly influenced to the HDD, which increased as the thickness decreased. In addition, the thinner panels showed much wider range in the HDD than those of thicker panels. The coefficient of variation (COV) of HDD also followed a similar trend to the panel density as the thickness increased. In summary, MDF panel thickness had a significant impact on the HDD within a panel. The sample size also showed a considerable effect to the HDD of MDF panels.

• Journal of architectural history
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• v.17 no.5
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• pp.7-22
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• 2008

The purpose of this study is to examine the function of wall posts in pit-houses in the Bronze Age, in the Kyung-nam Province. Wall posts were found as post-holes, created after wooden posts had decayed. In this research, the role of wall posts is newly defined from the perspective of a construction engineering. While existing studies in archaeology regard wall posts as sub-posts that support the roof of a pit-house, this study views wall posts as piles installed to support the soil wall, not as sub-posts. Based on the existing reports on excavation in prehistoric settlement sites by archaeologists, the study examines the remnants of the wall posts and remains after a fire. The main findings of this study are threefold. First, the wall posts were installed not as posts but as piles, cut sharply and hammered along the building lines of a pit-house. Second, wall piles were used to support the walls during earthwork, such as excavating and banking for low ground, mostly because a large amount of soil is often lost during the process. Third, wall piles were used as post piles of retaining walls that enabled the installation of transverse wall panels, which were used to prevent the soil loss.

• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.99-116
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• 1999

Wooden hollow core flush door is one of the main products of furniture manufacturing and woodworking industries. Warping and buckling of the door is serious problems in service. It has been reported that warping is caused by differences of physical and mechanical properties of face and back of skin panel for the door. This study focused on the prediction of warping and buckling phenomena of the flush door using numerical models. Predictions from the models were also compared with the experimental results obtained from the doors with plywood and hardboard skin panels under various environmental conditions. Three elastic constitutive models, so called elastic beam model, plate model and plate-buckling model, were employed to predict warping and buckling of the doors. It was observed that warping was more pronounced in low humidity condition than in high humidity condition. The plate model considering Poisson's effect was reliable to predict warping more closely than elastic beam model in low humidity condition. The plate-buckling model, however, was the best in the fitting of predictions with the experimental results under high humidity condition because buckling was developed in face and back of skin panel at that condition.

• Journal of the Korea Furniture Society
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• v.14 no.2
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• pp.31-38
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• 2003

This study was carried out to investigate characteristics of wood-based panels and wood-cement board for the possible uses as flooring and wall materials. The optimum cement/wood ratio(C/W ratio) of wood~cement board manufactured by clamp-pressing was from 2.7 to 3.2. The dimesional stability was superior in the C/W ratio of 3.2. Particularly, the dimensional stability of cement board using fine particle for particleboard face layer was favorable through three levels of C/W ratio. According to types of wooden material, bending strength of cement board using coarse particle for particleboard core layer or old newspaper(ONP) fiber was relatively higher than others. Thermal conductivities of wood-cement boards were no lower than that of gypsum board, and higher than those of plywood and boards. In case of wood-cement board of the C/W ratio of 2.7, the fire-proof performances of cement composite boards were greater than that of gypsum board, and weight loss reached to about a half of gypsum board. Then, wood-cement boards showed superior fire-proof performance compared to wood-based panels.

• Journal of the Korean Wood Science and Technology
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• v.20 no.3
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• pp.39-54
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• 1992

Hollow core wood flush doors for wardrobes, and other general openings and bathroom were designed and fabricated to investigate the factors causing the bowing of them and to find out the countermeasure for the phenomena. Balance in grain orientation, thickness, specific gravity and M.C.(%) of face panel and symmetrical construction were the essential factors to prevent the deflection of flush doors just after manufacturing. Under one-sided severe service condition, the unbalance of M.C. between opposite face panels is inevitable. So the material as thick plywood with high stiffness is considered as an alternative for the stile. UF resin mixing into PVAc emulsion is preferred for bathroom.

• Journal of architectural history
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• v.18 no.6
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• pp.127-144
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• 2009

This thesis aims to analyze the architectural form for the restoration of noogak(樓閣), Boje-roo(普濟樓) which was constructed at the central court of Beomeo-sa(梵魚寺). The results are as follow; 1. Boje-roo was established in 1700. By the constructional records and poetic essays of the times, the architectural of the establishment building was consisted fo two stories structure. The passage system for the approach to the court was the nuha-jinip(樓下進入), that is to say, one might walk between the columns of lower story of the building. And one could ascent the upper stairs and approach to the upper level, inner court. 2. By the remodelling in 1812, the building was varied to one story structure. Therefore the passage system for the approach to the inner court transformed from the nuha-jinip to the ugak-jinip(隅角進入), that is to say, one might ascent the atairs of the podium and could approach the inner court through the both sides of the building. 3. Under the Japanese imperialistic rule, the structure of it's roof and walls of Boje-roo were altered to the Japanese style. In 1965, the wooden columns were shifted to the concreted column, and the wooden wall-panels were shifted to the brick wall attached stone slates. 4. Conclusively speaking, for the restoration of Boje-roo, the establishment form in 1700 is the more proper than the remodelling form in 1812.

• Journal of the Korea Furniture Society
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• v.21 no.1
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• pp.72-82
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• 2010

The objective of this study is to identify the species of 17 wooden Buddhist statues of the late Joseon Dynasty (the 17th and 18th century) in Jeollado, southwestern region of Korea. The bodies of statues were made of Ginkgo (Gingko biloba L.: 88%) and alder (Alnus spp.: 12%). The hands of statues were alder(64%), willow (Salix spp.: 27%) and Ginkgo(9%). The bottoms of hollow bodies were covered all with Japanese red-pine (Pinus densiflora S. et Z., 'sonamu') panels. The main species of statue body, Ginkgo tree was known to be introduced to Korea from China with Buddhism. The results indicated that Ginkgo trees of Korea in the 17th century had already become large and rich enough to be used for most of statues. Ginkgo wood has low shrinkage and even texture, which are crucial for carving sculptures. Alder and willow woods used for statue hands have fine and firm textures. The pedestals for these statues were also made of red pine wood. Red pine woods have rather high shrinkage and low hardness, but it is versatile woods strong enough to support heavy statues.