• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.66-75
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• 2005

Soybean-based adhesives have recently been reconsidered as alternatives to petroleum-based adhesives due to the uncertainty of availability of petrochemical products and the increased demand for wood adhesives. This study was conducted to investigate the adhesive properties of alkaline phenolic soy (APS) resin for hybrid poplar flakeboard. The APS resin was formulated by crosslinking an alkaline soy flour hydrolyzate with lab-prepared PF resin in the soy hydrolyzate to PF resin weight ratios of 70/30, 60/40, and 50/50. The APS resins were used to fabricate homogeneous hybrid poplar flakeboards with different resin solid levels (5%, 7%, and 9%), press temperatures (175 and $200^{\circ}C$), and press times of 8 and 10 minutes. The IB, wet MOR, and dimensional stability properties of board improved with increasing press time, press temperature, and PF level in APS resins. Increasing press time can be used to offset poor IB strength associated with a 9% resin solid level and the excessive moisture content in the mat. The following conditions were concluded to meet the requirements of the CSA standard for exterior-grade flakeboard: a 50% PF level, a 5% resin content, a $200^{\circ}C$ press temperature, and an 8 minute press time.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2007.11a
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• pp.93-102
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• 2007

Biocomposite was organized with biodegradable polymer and natural fiber that has potential to be used as replacement for glass fiber reinforced polymer composite with the benefits of low cost, low density, acceptable specific strength, biodegradability, etc. Until now, non-wood fibers have been used as reinforcements of biocomposite which are all plant-based fibers. The present study focused on investigating the fabrication and characterization of biocomposite reinforced with red algae fiber. The bleached red algae fiber(BRAF) showed very similar crystallinity to the cellulose. It has high stability against thermal degradation (maximum thermal decomposition temperature of 359.3$^{\circ}C$) and thermal expansion. Biocomposites reinforced with BRAF have been fabricated by a compression molding method and their mechanical and thermal properties have been studied. The storage modulus and the thermomechanical stability of PBS matrix are markedly improved with reinforcing the BRAF. These results support that the red algae fiber can be used as an excellent reinforcement of biocomposites as "green-composite" or "eco-composite".

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.1
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• pp.10-18
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• 2004

The urban ecosystem, unlike the natural ecosystem, has been affected by the urban environment, so the existences of normal creatures have been threatened and eventually the stability has declined to consist of those that have adapted to such. Therefore, by creating a list of such organisms, their number of variety can be found out and their ecological distinction can be understood. Because flora is known to be an ecological index reflecting region's effects of human and societal environments, weather, and climates, it is a useful method of finding out the ecological position and distinctiveness of that region. The study site is part of watershed at Yangjae Stream, Kahngnam-ku, Seoul. In this study, the difference of flora in each land use type are investigated by plant identification. The purpose of this study is to evaluate the city's plant surviving environment, and eventually to contribute to the restoration of urban green spaces by finding out the plants which are appropriate for the corresponding environment. After doing the study, it was found that the urban forest is the most stable urban ecosystem while the urban park is seriously disturbed, and ecologically unstable. The urban stream is also disturbed continuously.

• Korean Journal of Remote Sensing
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• v.28 no.6
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• pp.661-670
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• 2012

Urban forests provide great ecosystem services to population in metropolitan areas even though they occupy little green space in a huge gray landscape. Unfortunately, urbanization inherently results in threatening the green infrastructure, and the recent urbanization trends drew great attention of scientists and policy makers on how to preserve or restore green infrastructure in metropolitan area. For this reason, mapping the spatial distribution of the green infrastructure is important in urban environments since the resulting map helps us identify hot green spots and set up long term plan on how to preserve or restore green infrastructure in urban environments. As a preliminary step for mapping green infrastructure utilizing multi-source remote sensing data in urban environments, the objective of this study is to map vegetation volume by fusing LiDAR and multispectral data in urban environments. Multispectral imageries are used to identify the two dimensional distribution of green infrastructure, while LiDAR data are utilized to characterize the vertical structure of the identified green structure. Vegetation volume was calculated over the metropolitan Chicago city area, and the vegetation volume was summarized over 16 NLCD classes. The experimental results indicated that vegetation volume varies greatly even in the same land cover class, and traditional land cover map based above ground biomass estimation approach may introduce bias in the estimation results.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.187-194
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• 2008

LiDAR는 일반 항공사진 및 위성영상과는 달리 사물의 높이를 측정할 수 있어 산림의 3차원 모델링을 수행할 수 있다. 본 연구에서는 이러한 LiDAR의 특성을 이용하여 산불이 발생한 강원도 양양지역 산림의 물리적 피해를 분석하였으며, 디지털 항공사진으로부터 Normalized Difference Vegetation Index (NDVI)를 추출하여 산림의 생물학적 피해를 분석하였다. 산림의 물리적 피해는 임관의 피해정도에 따라 지표면에서 반사되는 Point Data의 개수의 비율로서 추정을 하였다. 피해정도의 고저(高低)를 구분하는 기준은 통계적 방법 (Jenk's Natural Break) 으로부터 추정된 0.3594을 사용하였으며, 지표면 반사비율이 0.3594 이상인 경우 물리적 피해정도를 고(高, Serious Physical Damage; SPD), 지표면 반사비율이 0.3594 이하인 경우 물리적 피해정도를 저(低, Light Physical Damage; LPD)로 나타내었다. 또한 생물학적 피해는 일반적인 NDVI 값의 범위(-1

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.257-263
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• 2006

This paper examines the physico-chemical properties and structural features of thio lignin and alcohol lignin preparations extracted from fast-growing poplar wood. The lignin preparations were characterized using UV, IR and alkaline nitrobenzene oxidation methods. The yield was higher in thiolignin due to its preparation from wood under drastic alkaline conditions and almost the total amount of alkaline degraded lignin was precipitated except acid soluble lignin. In case of ethanol lignin, structural modifications were comparatively less and form a cream colored lignin more or less similar to its original natural color. The methoxyl values were higher due to syringyl unit present in hard wood lignin in addition to guaicyl unit present in soft wood. The higher values of methoxyl content of isolated lignin revealed that it was built up of high syringyl units. The elementary analysis, methoxyl group and hydroxyl groups were presented by $C_{9}$ formula indicated that it was made up of phenyl propane monomers. Nitrobenzene oxidation of thio lignin and ethanol lignin yield more or less the chromatograms of similar pattern, except difference in relative percentage. The ultra violet spectra of lignins were quite similar, irrespective of the source and method of isolation. Infrared spectroscopy studies of poplar deltoides, thio and ethanol lignin shown different absorption bands which have been utilized for structural investigations.

• Journal of the Korean Wood Science and Technology
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• v.26 no.1
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• pp.70-75
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• 1998

In this paper, the relationships between volumetric mixing ratio of rubber chip and physical and mechanical properties of wood/rubber composite panel was examined in order to investigate the mixture characteristics of wood and rubber chip. Because of the specific gravity of rubber differed from wood chip, physical properties of wood/rubber composite panel was shown very different values by mixing rate of chip element. Specific gravity in air-dry of composite panel was increased rapidly as volumetric percent of rubber chip was increased. Moisture content of composite panel was decreased as volumetric percent of rubber chip element was increased. This results was considered that wood weight is light and porosity material for moisture absorption. Compressive strength and modulus of rupture in bending test were decreased as volumetric percent of rubber chip increased. By mixing ratio control of chip elements, various wood/rubber composite panel can be applicable to every interior materials such as subfloor, playground, and exterior materials such as road blocks for recreational facilities in garden and forest and city parks.

• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.104-111
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• 2001

There are some evidence that active enzymatic proteins, e.g. fungal laccase, exist in the naturally occured soil humus. This study was performed to investigate the covalent binding of fungal laccase to the humic acid-iron complex, and to measure laccase activity of immobilized ones. Seven methods were adopted to form the covalent binding of fungal laccase with soil humic acids complexed with iron. Using these seven methods it was possible to change the dimension of spacer arm between laccase and support, and also to regulate the mode of covalent binding of this enzyme. The spacer arm was regulated from 2C to 11C. There was not observed any straight relationship between the spacer arm longitude and the laccase activity after immobilization, but the binding mode more effective than the former. Three out of the seven methods gave the high activity of immobilized laccase, and which active products of laccase immobilization was stable up to 10 days after the process. It is indicated that natural soil condition might be prevented the laccase activation by the toxic influence of some phenolic humic compounds. It was shown, for the first time, the possibilities to obtain the high activity of fungal laccase by binding to humic acids, and especially in complex with iron.

• Journal of the Korea Furniture Society
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• v.13 no.1
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• pp.71-83
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• 2002

This study was carried out to develop colored-wood furniture using veneer, small-round log and fiberboard to protect forest resources through the study of minimalism. which advocates the environmental issue inherent to contemporary furniture in the postmodern era. Based on the historical and theoretical context of minimalism closely related to the environmental protection, this study suggested the technical way how to produce the environment-friendly furniture with the least use of valuable and natural log. Finally, the color-wooden furniture was developed based on the asceticism, simplification, and repetition of the minimalism in a trend of contemporary furniture design. By soaking a veneer, Psuedotsuga menziesii and small-round log, Pinus densiflora into a very-diluted organic dye, the environment-friendly and colored-wood furniture could be created in harmony with contemporary interior space, which has showed various colors such as yellow, blue, red, and green with a pastel tone. The spring wood of the colored softwood was deeply stained, while the summer wood was lightly done. By utilizing such valueless used woods which have been little in furniture production, it was possible to decrease the consumption of precious raw log such as zelkova, ebony, rose, maple, cherry, mahogany and so on. Thus, it became obvious to be able for contemporary furniture designers to produce beautiful furniture with dyed fiberboard and small-round logs pregnant with minimalism.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.3
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• pp.67-81
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• 2018

We tried to analyze qualitatively a total of 110 the research papers which were related domestic ecological restoration technologies about 15 years through semantic network analysis in social network analysis. In order to understand the research trends of ecological restoration technologies, we analyzed the degree centrality and betweenness centrality of the Stream/Wetland, Slope, Soil/Others fields selected as Word Cloud. As a result, ecological restoration technologies have been changed. They were focused on the restoration of species or their habitats in the past. However, they have been evolved into the detailed systems to respond in unpredictable natural disasters and climate change, high-resolution image implementation technology to accurately grasp the practical environment and methods related to environmental restoration for human in urban ecosystem. In the future, investment and technology for the ecosystem restoration field will be continuously demanded for the symbiosis of human beings and species in the damaged ecosystem. Therefore, the research trend of ecological restoration technologies should be provided as reliable guidelines when decision makers establish the policy direction or when researchers select their subjects.