• Journal of the Korean Wood Science and Technology
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• v.32 no.3
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• pp.42-51
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• 2004

Wood veneer-bamboo zephyr composite board (WBCB) was manufactured to evaluate the properties of bamboo as alternative raw materials for the manufacture of composite panels. Bamboo zephyr was prepared using Moso bamboo (Phyllostachys pubesens Mazel. et Z), Giant timber bamboo (Phyllostachys bambusoides Sieb. et Zucc), and Hachiku bamboo (Phyllostachys nigra var. henosos Stapf). The effect of age and species of bamboo on zephyr production was investigated in terms of the pass number of bamboo split through the rollers, and the width increasing rate of bamboo split. Five-ply WBCBs were produced with Keruing veneers as face and back layers, leading to three layers of bamboo zephyr sheets as core layer. Each layer was placed so that its grain direction was at right angles to that of the adjacent layer and the layers were bonded together with phenol-formaldehyde (PF) resin.The pass number of bamboo split was increased with an increase of the thickness of culm wall. At the same thickness, Moso bamboo showed no effect of the age of bamboo on the pass number. The pass number of split of Giant timber bamboo was lower than that of Moso bamboo. No significant effect of bamboo species and age on the width of zephyr produced was observed. The width of zephyr obtained could be expressed as a function of diameter multiplied by thickness of culm wall. The physical and mechanical properties of WBCB manufactured in all given conditions did not show any significant differences, and they were above the requirement of Korean Standard (KS).

• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.561-573
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• 2023

National forests have an advantage over private forests in terms of higher investment in capital, technology, and labor, allowing for more intensive management. As such, national forests are expected to serve not only as a strategic reserve of forest resources to address the long-term demand for timber but also to stably perform various essential forest functions demanded by society. However, most forest stands in the current national forests belong to the fourth age class or above, indicating an imminent timber harvesting period amid an imbalanced age class structure. Therefore, if timber harvesting is not conducted based on systematic management planning, it will become difficult to ensure the continuity of the national forests' diverse functions. This study was conducted to determine the optimal volume of timber production in the national forests to improve the age-class structure while sustainably maintaining their economic and public functions. To achieve this, the study first identified areas within the national forests suitable for timber production. Subsequently, a forest management planning model was developed using multi-objective linear programming, taking into account both the national forests' economic role and their public benefits. The findings suggest that approximately 488,000 hectares within the national forests are suitable for timber production. By focusing on management of these areas, it is possible to not only improve the age-class distribution but also to sustainably uphold the forests' public benefits. Furthermore, the potential volume of timber production from the national forests for the next 100 years would be around 2 million m³ per year, constituting about 44% of the annual domestic timber supply.

• Journal of Forest and Environmental Science
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• v.9 no.1
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• pp.33-43
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• 1993

About 67% of all forest area in Korea belong to young age stands under II age class, including III age class which can be thinned under DBH 16cm, it comes up more than 90%. Therefore, thinking of the pressing necessity of thinning in our country this study describes the actual conditions analysis of the production of thinned small logs, points at issue and improvement measures of thinned timber production.

• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.523-529
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• 2023

The aim of this study was to analyze the potential for timber harvesting in the Hongchoen Garisan Leading Forest Management Complex in the national forests, and to suggest an optimal target yield for sustainable timber harvesting. The potential for timber harvesting was assessed by analyzing the area available for timber harvesting using GIS spatial analysis, but excluding areas with a slope of more than 40° (topographical constraints), areas within 30 m on both sides of streams (environmental constraints), and areas more than 300 m away from forest roads (technical constraints). The analysis identified 3,298 ha (49%) of the total complex area of 6,679 ha as available for timber harvesting, yielding a potential harvesting volume of 608,613 m³. In the case of coniferous plantations, the potential harvesting volume was 409,721 m³, which was a very high level that accounted for 67.3% of the total. We also conducted an optimization analysis to minimize the differences in area between age classes, while maintaining sustainable timber harvesting for the next 50 years. An annual average of 41.9 ha (7,988 m³) was determined to be the optimal timber yield, and in this case, it was possible to convert the age class structure to a more stable structure after 50 years.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.256-272
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• 2002

The purpose of this study is to develop landslide susceptibility analysis techniques using artificial neural network and to apply the newly developed techniques to the study area of Boun in Korea. Landslide locations were identified in the study area from interpretation of aerial photographs, field survey data, and a spatial database of the topography, soil type, timber cover, geology and land use. The landslide-related factors (slope, aspect, curvature, topographic type, soil texture, soil material, soil drainage, soil effective thickness, timber type, timber age, and timber diameter, timber density, geology and land use) were extracted from the spatial database. Using those factors, landslide susceptibility was analyzed by artificial neural network methods. For this, the weights of each factor were determinated in 3 cases by the backpropagation method, which is a type of artificial neural network method. Then the landslide susceptibility indexes were calculated and the susceptibility maps were made with a GIS program. The results of the landslide susceptibility maps were verified and compared using landslide location data. A GIS was used to efficiently analyze the vast amount of data, and an artificial neural network was turned out be an effective tool to maintain precision and accuracy.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.3
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• pp.363-371
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• 2021

Forest operations like timber harvesting have already been mechanized to reduce hazards to the worker and increase productivity. However, timber harvesting operations have still been considered potentially dangerous and expensive on steep terrain. Teleoperation, to control the timber harvesting machine at a distance, has the potential to improve the safety, productivity and efficiency of harvesting operations on steep terrain. To verify the effects of teleoperation, an experimental prototype system of a monitor image-based teleoperation was constructed using a real forestry machine. In this study, the productivity of excavator based grapple loader, which is one of the most used mechanized harvesting equipment in the timber production, was analyzed using time-study method. Factors like skill and age of operators, influencing loader productivity in timber loading operation were also evaluated by statistical analysis. Productivity analysis results showed that less experienced operators were more productive than experienced operators for teleoperation through image of monitors in the operator cabin. These results are shown to be unfamiliar to the monitor image and different loading operation pattern by operators. According to the results, the monitor image-based teleoperation system of forestry machine need to improve the resolution and installation position of camera. It was expected that additional studies will be needed for real-time remote control of forestry machine in the future.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.504-511
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• 2020

This study estimated planned felling volumes to set targets for management planning of nationwide country-owned forests. Estimates were made using timber harvest prediction methods that use probability density functions, including area weighting (AW), area ratio weighting (ARW), and sample area change ratio weighting (SCRW). Country-owned forest areas in 2010 and 2015 were used to estimate planned felling volumes, as shown in basic forest statistics, and calculations were made assuming that the felling areas were the changes in the forest area over the 5-year period. For the age classes of V-VI, the average felling ages for AW, ARW, and SCRW were 5.41, 5.56, and 5.37, respectively, and the felling areas were 594,462, 586,704, and 580,852 ha, respectively, with ARW reaching closest to the actual changes. The actual changes in the areas and chi-squared test results were most stable with the SCRW method. This study showed that SCRW was more adequate than AW and ARW as a method to predict timber harvests for forest management planning.

• Journal of architectural history
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• v.16 no.1
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• pp.29-48
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• 2007

This study is an investigation that explication of the reading method of transcription marking, and explains what it means and where to use transcription marking of architectural vocabulary. focusing on timber class vocabulary from on SeoGwolYeongGeonDoGamUiGwe(${\ulcorner}$西闕營建都監儀軌(1831)${\lrcorner}$). This study is reviewed sequentially classifying items according to timber class, stone class, iron class architectural vocabulary. This treatise, named 'Architectural Vocabulary Study (1)', is mainly focused on making out a transcription marking of timber class vocabulary on the documents. But, because of the properties of the UiGwe(儀軌), there are some different expressions used for the same vocabulary. Therefore, the different expressions are referenced according to vocabulary used from the 17th century to the 20c century. This study lists timber class architectural vocabulary of transcription marking on SeoGwolYeongGeonDoGamUiGwe(${\ulcorner}$西闕營建都監儀軌(1831)$\lrcorner$). This study also explicates and explains the meaning of them. In advance, this study compares them with the vocabulary of national language in the middle ages and modern times. If we could explicate the transcription marking of the documents as it is, we can't only recover plenty of vocabulary related with characteristic architecture in the age of later Chosun Dynasty, but also correct wrongly used vocabulary nowadays. With the results, we can standardize and adjust vocabulary use of Korean traditional architecture. In advance, we can correct errors of spelling and mistaken explanation in the Korean Encyclopedia.

• Journal of Forest and Environmental Science
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• v.30 no.4
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• pp.315-321
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• 2014

Forest timber production potential of any site is oftentimes measured quantitatively by site index, which is defined as dominant height of a particular stand at a specified age. A site index was developed for estimating site quality of monoculture Pinus caribaea plantations in southwestern Nigeria using a base age of 25 years. Dominant height data were collected from 60 Temporary Sample Plots (TSPs) of $20{\times}20m$ in plantations of 15 to 37 years. Linear and non-linear models as been widely applied in quantitative forest measurements were fitted to dominant height-age data and the best site index equation is : $SI=Exp^{(InHd-23.495(A^{-2}-0.04)}$. The site index curves constructed for the three sites (Omo Forest Reserve - OFR (J4), Oluwa Forest Reserve - OLFR and Shasha Forest Reserve - SFR) across the southwestern Nigeria using the chosen equation revealed that a 15 year old Pinus caribaea in the study area attained average dominant heights of 25, 22 and 21 m in OFR (J4), OLFR and SFR respectively. The site index equation and curves proffer veritable insight into better silvicultural options and management practices for the future plantations suitable sites.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.427-435
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• 1991

Linear programming(LP) is a well-known method in optimizing timber harvest schedules. This paper describes a linear programming formulation of korean pine stands for timber harvest scheduling problems. Simulation technique and LP were applied to optimize the time and space distribution of the sustained yield for the 10-year forest management planning horizon. Growthfunction of korean pine stands in study area was derived with the yield table. This growthfunction was contained to the simulation model in estimating of changing stand volume conditions for the planning horizon. These estimated values were served as the basic data of LP model, and LP model was formulated with the maximum of periodical harvest volume calculated by the classical yield regulation method (Paulsen-Hundeshagen formula) and the maximum of periodical harvest area calculated for the normal age distribution. The timber harvest schedule was established periodically for each subcompartment of korean pine stands in experiment forest of College of Forestry in Kangweon National University with the here developed LP model.