• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.337-345
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• 2013

Log grading rules are essential tools to ensure the quality of logs in distribution structure. The rules should reflect the long experience and accepted usage practice in the market. A gap between the rules and market should be improved based on analysis of log qualities that produced and market demand. In this study more than ten millions logs which were produced by 5 Regional Forest Services in 2010~2011 period, were analyzed in their qualities including diameters and lengths by species. A proposal was driven to improve the current log grading rules in terms of log diameter classes and length. The followings are the summary of this study. Most of domestic softwood logs are belong to small diameter class of 100~160 mm, which imply the diameter classes of current log grading rules are immoderate. Distributions of log diameter shows distinctive patterns by species, which indicate a necessity of differentiated diameter classes by species in an improved rules. Lengths of logs in productions do not corresponding to the demands and preferences in sawmills. Therefore it is highly recommended to include log length term in an improved log grading system. Based on these findings, 6 log grading systems for 3 species groups of softwood are newly proposed to improve current log grading rules. Limits of log diameter and log length are also proposed for each log grading system.

• Korean Journal of Organic Agriculture
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• v.21 no.3
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• pp.335-350
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• 2013

With the efforts to development of renewable energy technologies, and increasing awareness to environmental issues, the usage of wood pallets has been increasing every year since the introduction of wood pallet technology to the domestic market. until 2009, majority usage of pellet boiler was in the residential houses. In an effort to increase the distribution of wood pellet boiler to cultivation facilities with high usage of fuels, The Ministry of Agriculture and Forestry has launched a distribution project of wood pellet boiler for fuel usage as a part of the agricultural and fishery energy efficiency projects. Although only small number of farms with a heat-culturing facility have replaced from conventional boiler to pellet boiler. Although part of reason for low usage of pallet boiler is lack of understanding and information of it, the main reasons are high initial cost and uncertainty of its cost efficiency. Also, most people from agricultural industry don't realize it's significance in terms of environmental benefit due to lack of understanding in 'resource circulation' and 'adopting to climate change'. In this study, first, we did a cost-efficiency analysis of the farm which uses a diesel boiler to grow cucumber, tomato, paprika. Then we replaced the diesel boiler to a pallet boiler and measured its cost-efficiency again. By comparing the cost-efficiency of the diesel boiler with the pellet boiler, we analyzed the economic viability of pellet boiler. Then we analyzed viability of pallet boiler usage in terms of 'resource circulation' and 'adopting to climate change'. As a result of our analysis, we have found out that under the current system of government support, the energy usage varies depends of the types crops grown and the higher the energy use, the more cost efficient it is to use the pallet boiler. Also, it is economically viable to use the pallet boiler in terms of 'resource circulation' and 'adopting to climate change'.

• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.41-51
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• 1998

This study not only carried out to grasp about the sununarized characteristics of the relationship between international timber market and production trend of wood products, but also focused on the analysis of korean wood demand and the long-term forecast with econometric analysis. The result of regression analysis for wood demand in Korea is that coniferous roundwood demand(CIWD) is explained by coniferous foreign roundwood price(CWRI), Gross domestic product(GDP), a dummy variable. Non-coniferous roundwood demand(NCIWD)is explained by non-coniferous roundwood price(NCWRI), coniferous roundwood price(CWRI), a dummy variable. As the result of long-term forecast by base case, the total roundwood demand was forecasted $11,107,000m^3$ in the year 2000, $11,781,000m^3$ in 2005, $12,565,000m^3$ in 2010. As the result of scenario 1, total roundwood demand was forecasted $11,027,000m^3$ in 2000, $11,435,000m^3$ in 2005, $11,952,000m^3$ in 2010. And as the result by scenario 2, total roundwood demand was forecasted $11,341,000m^3$ in 2000, $12,208,000m^3$ in 2005 $13,257,000m^3$ in 2010.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.475-480
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• 1999

Recently domestic building market in the face of 3D, in addition to construction cost increase, materials lack problems and opening a building market to foreign countries, is trying to find out the efficient ways of overcoming these problems. So the necessity to study the permanent form is urgent to escape the problems of constructing human power economy, cost down, noises problem, environmental prevention and efficacy of form work to technical improvement will contribute a practical permanent form in field through economic evaluation of permanent form. In this paper, we compared wood form cost with permanent form cost(made form polymer or fly ash) for frame work

• Fire Science and Engineering
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• v.29 no.3
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• pp.1-5
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• 2015

The productivity and demand of porous material has been increasing by development of industry and increasing income. In particular, the fire caused by using wood flour risks wood processing industry and stock farm. The heat transfer of wood flour is carried into the depth direction by effect of oxidizer around flame, flame sometimes is progressed as smoldering. In the case of progressing as combustion fire, identifying the location of fire is difficult, and it leads to failing fire aid fire fighting. Therefore potential cause is acted as raising additional damage. This paper conducts experiments of downward deep seated fire of natural convection conditions. The samples is New Zealand wood flour that is demanded much in the domestic and oversea market. In this experiment, temperature of deep seated side is measure by changing wood flour density in holder The densities used in experiment are 3%, 5%, 10%, 15%. As a result, the tendency of temperature inside decreases as wood flour density increases. But, in the case of density which is above $0.2140g/cm^3$, the phenomenon, decreasing temperature, is not shown. The result of measurement show that average flame spread speed of wood flour is 0.249 mm/min.

• Journal of the Korean Wood Science and Technology
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• v.18 no.3
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• pp.53-68
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• 1990

This research has been executed for maximization of lumber yield and more efficient use of small diameter logs. Sample logs from thinnings carne from densed artificial stands at the Kwangnung Experimental Forests situated in the central region of Korean peninsula. Species of sample logs were obtained to execute sawing and strength test for larch, and lumber strength test in full size for pitch pine and Korean pine. A survey on sawmills consuming domestic logs was carried out to know sawmill production, costs and utilization structure of lumber as a guide to business analysis. Results showed that sawing pattern from small logs less than 15cm in diameter was necessary to cut 9cm by 9cm square per one log in order to obtain high lumber recovery and provide for wide market needs. The total lumber yield of squares plus side boards was 56 percent to 58 percent from small logs and the yield for log sweep in 30 percent decreased by 24.5 percent in sawing production, compared to yield for straight logs. In sawing efficiency, production of lumber by twin band saw could be improved 238 percent higher than lumber of the same species produced by conventional sawmilling methods, and sawing accuracy with twin band saw was much higher at the lumber production than band saw. Lumber from the small larch logs has shown 70 knots per $m^2$ on its faces and also lumber showed lots of face checkings by air drying on the yard, compared to other species. MOR in bending of lumber in full size from small logs of larch was found ranging from 380kg/$cm^2$ to 460kg/$cm^2$, resulting in 40 percent less than the strength from clear small specimens. In lumber containing knots, cross grain, etc, longitudinal stress wave speed was delayed about 48 percent by defects in lumber from both larch and pitch pine logs. The surveyed sample sawmills consumed the domestic logs at the rate of 54 percent to 84 percent in the total timber consumption, showing high consumption at mills located in the mountains.

• Journal of the Korea Furniture Society
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• v.23 no.2
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• pp.122-129
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• 2012

This article was intended as fundamental materials to recognize the current status of furniture hard ware in Korean market and to fix the identity of Korean furniture, by investigating and comparing the furniture hard ware used in the Joseon era and in modern times by type, function, shape and material. The analysis of furniture hard ware of the Joseon era and modern times from the view of functional aspects was oriented to the hard ware necessary to open and close the door & drawer on one side, and to that being attached to the main body of furniture not to scratch the wood by another wood on the other side, and from this the following conclusion was drawn. First of all, "Gwangdoojung" - a kind of spike- and metal decoration on the edge of the furniture disappeared, while the function-oriented hard wares have been diversified in modern times, from the perspective of the change of kinds. Second, the functional aspect of the furniture hard ware was emphasized in modern times than the Joseon era. In other words, the hard wares of the Joseon era came into view due to their strong appeal to decoration, whereas those of modern times were mostly hidden or moderated, keeping the function substantially. Third, the hard wares from the Joseon era were shown in concrete and detailed shape motivated by natural objects and furthermore even gloriously, but the modern hard wares are simple & basic geometry, from a formative point of view. Fourth, the material aspects present that the Joseon era's hard ware was mainly cast iron, whereas that of modern times shows the diversification from metal to even plastic. Finally, the recent trend in naming of the hard wares is the words of foreign origin. This resulted from that the foreign names of hard wares are valid also after import process in Korean market, so the domestic development of hard ware as the essential factor for the furniture design is urgently necessary to establish the identity of Korean modern furniture.

• Journal of the Korea Furniture Society
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• v.20 no.5
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• pp.440-456
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• 2009

Because PBD was started as a design tool for steel construction and concrete construction, it was able to applied to the post and beam method of wooden building constructions. But, it may not suitable to light frame wooden construction that is becoming popular in domestic construction market due to the economical efficiency and the constructive simplification. Owing to the share effects between member and sheathing material or among structural members, light frame wooden construction is different from post and beam construction that use a single structural member. Therefore, consideration on the system analysis and system design are urgently needed to use in actual life and inspect the reliability of structures from the system view. With this in mind, code conversion from ASD to PBD that is pressing issue in domestic wooden building construction was studied, also various countries status about PBD were considered and then approaching methods on the system reliability were referred. Finally, several considerations for the development of PBD were explored. PBD should be considered as, not only a new structural design process that select sizes of structural member, but a industrial tool that can lead a development of more reliable wood products. A strongest point of PBD is independent of various construction materials and construction types.

• Journal of the Korea Furniture Society
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• v.28 no.4
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• pp.340-354
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• 2017

Currently, the global furniture market can not overlook environmental problems due to changes in environmental regulations. In order to grow into a global corporation, environmentally friendly design became essential. In addition, domestic and foreign consumers are increasingly interested in and spending on children's furniture, and demand for environment - friendly furniture for children's health and emotional development is increasing. In the era of universal consumer tastes due to massive mass production, it has been changed into a multi-product small-volume production period that reflects the preferences of various consumers, so that various types of furniture that meet individual preferences are required. Therefore, in this study, we investigated various personal opinions, perception, preference, propensity to use furniture, purchasing points, etc. for environmentally friendly children's furniture, and provided basic data for environmentally friendly children's furniture development that reflects consumer preference and requirements. Accordingly, 243 parents who have more than one child living in Seoul, Gyeonggi, and Incheon were surveyed about the use of children's furniture and the perception and preference of environmentally friendly children's furniture. According to the survey results, 64.57% of the respondents knew about eco - friendly children's furniture and the most popular way to get to know eco-friendly furniture was Internet advertising (49.48%). The rate of recognizing eco-friendly furniture as healthy furniture with no emission of hazardous substances was high as 56.16%. The purchase intention of eco-friendly children's furniture was very high at 86.01% and the most important factor in purchasing was the harmlessness to the human body (56.88%). 59.50% said that it is not possible to distinguish environmentally friendly furniture, which means that there is not much information to consumers yet. In addition, the preferred price range is 500~1000 thousand won, and the preference for the rest furniture is high. In the preferred form type, unit type modular furniture is 36.13%, in the material, wood is 72.35%, in the color, the color of wood with wood grain is high as 45.56%.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.1
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• pp.21-24
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• 1999

The analysis of hazard compounds, including naphthalene, biphenyls (BP) and diethyl phthalate (DEP), was conducted from the wooden kitchenwares and sanitory produce. Fifty samples of that wooden products in the local market were purchased for the study. All the samples were extracted by benzene and n-heptane, followed by the analysis through GC-MSD. As a result, neither naphthalene nor diethyl phthalate were found, however, trace amount of biphenyls were detected on all the samples ranged from 0.1 to 3.1 ppm. Biphenyls also contained both in the imported and the domestic of White Birch wood, as 0.25 ppm and 0.34 ppm, respectively. The concentration of biphenyls reduced with the process of the original woods, and especially the detection range was relatively low compared with the permission one of apples (110 ppm). The results suggested that biphenyls were contaminated into the product not by the addition doting the process of manufacture, but as the component itself in raw wood materials. Also, the content of the residual biphenyls were not suspected to give the harmful effects.