• Title/Summary/Keyword: PLANE FOREST

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Ecological Changes of Seunghwanglim -Natural Monument No. 93- Wonju Seungnamri (원주 성남리 성황림-천연기념물 제 93호-의 생태적 변화)

  • Kim, Gab-Tae
    • Korean Journal of Environment and Ecology
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    • v.21 no.6
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    • pp.559-564
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    • 2007
  • This research is aimed at finding out the ecological change of Seunghwanglim through the examination of vegetational change of tree seedlings of old giant trees growing at Seunghwanglim [Seunghwang Forest designated as a Natural Monument No.93] after the installation of protective iron fence. The survey results are as follows: First, as a result of keeping out people by installing a protective iron fence in 1989, soil hardness of the plane forest was greatly improved except the area used as roads. The seedlings of the plane forest, whose damage index is 2,3,4, were found to have the highest 1,202 $individuals/400m^2$, and those of the plane forest, whose damage index is 1, were revealed to have 565 $individuals/400m^2$, and those of the slope forest were found to have 403 $individuals/400m^2$. The number of the young sapling[taller than 2 meters] individuals of the plane forest whose damage index is 1 was found to be the most $48/400m^2$, and that of the plane forest whose damage index is 2, 3, 4- was $31/400m^2$, and that of the slope forest proved to be $14/400m^2$. In the plane forest whose damage index is 2, 3, 4, the saplings of the Ulmus davidiana var. japonica and Acer triflorum are relatively much distributed, and in the plane forest whose damage index is 1, many saplings of the Prunus padus and Styrax obassia, were found to grow and in the slope forest, many saplings of the Acer pictum subsp. mono and Acer pseudo-sieboldianum. were found to grow. Many seedlings of Rubus spp. - R. oldhamii, R. coreanus and R. crataegifolius. - and Akebia quinata were growing vigorously on plane forest, but they might decrease in number with the increasing number of the tree saplings.

The Analysis of Relationships between Road Alignment and Terrain Conditions for National Forest Road (국유림도(國有林道)의 노선선형(路線線形)과 지형(地形)과의 관계분석(關係分析))

  • Cha, Du Song;Cho, Koo Hyun
    • Journal of Korean Society of Forest Science
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    • v.84 no.4
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    • pp.517-524
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    • 1995
  • This study was conducted to investigate the characteristics of the road alignment, correlations among evaluation factors of the alingment, and the relationships between the evaluation factors and terrain factors for the forest road of five National Forest Offices. The results were as follows : 1. The elongation coefficients(${\eta}$) of forest road in Kangnung and Wonju National Forest Office were ranged 0.3~0.5, and those of Andong, Namwon, and Kongju National Forest Offices were ranged 0.2~0.3 in straight line of 100m, 200m, and 300m. 2. Three different types of plane alignment were identified for Kangnung and Wonju National Forest Offices, Namwon and Kongju National Forest Offices, Andong National Forest Office. However, longitudinal alignment for five National Forest Offices tended to be similar conditions. 3. Low correlation coefficients were calculated in the relation between elongation coefficients(${\eta}$) and evaluation factors of plane alignment(curve length ratio(%), sum of inverse number of each curve radius(m/km), and sum of each intersection angle($^{\circ}/km$)) for three straight lines. On the contrary, high correlation coefficients were obtained among the relations of curve length ratio(%), sum of inverse number of each curve radius(m/km), and sum of each intersection angle($^{\circ}/km$). 4. Slope(%) were closely correlated with plane alignment, and so were the relationships between frequency of valleys and streams(No./km) and elongation coefficients(${\eta}$) of forest road.

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Bending Behavior of Nailed-Jointed Cross-Laminated Timber Loaded Perpendicular to Plane

  • Pang, Sung-Jun;Kim, Kwang-Mo;Park, Sun-Hyang;Lee, Sang-Joon
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.6
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    • pp.728-736
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    • 2017
  • In this study, the bending behavior of cross-laminated timber (CLT) connected by nails were investigated. Especially, the load-carrying capacity of the nail-jointed CLT under out-of-plane bending was predicted by the lateral resistance of the used nails. Three-layer nail-jointed CLT specimens and a nail connection were manufactured by 30 mm (thickness) ${\times}$ 100 mm (width) domestic species (Pinus koraiensis) laminas and Ø$3.15{\times}82mm$ nails using a nail-gun. Shear test for evaluating the nail lateral resistance and bending test for evaluating the load-carrying capacity of the nail-jointed CLT under out-of-plane bending were carried out. As a result, two lateral resistance of the used nail, the 5% fastener offset value and the maximum value, were 913 N and 1,534 N, respectively. The predicted load-carrying capacity of the nail-jointed CLT by the 5% offset nail lateral resistance was similar to the yield points on the actual load-displacement curve of the nail-jointed CLT specimens. Meanwhile, the nail-jointed CLT specimens were not failed until the tension failure of the bottom laminas occurred beyond the maximum lateral resistance of the nails. Thus, the measured maximum load carrying capacities of the nail-jointed CLT specimens, approximately 12,865 N, were higher than the predicted values, 7,986 N, by the maximum nail lateral resistance. This indicates that the predicted load-carrying capacity can be used for designing a structural unit such as floor, wall and roof able to support vertical loads in a viewpoint of predicting the actual capacities more safely.

On Estimation of Zero Plane Displacement from Single-Level Wind Measurement above a Coniferous Forest (침엽수림 상부의 단일층 풍속 관측으로부터의 영면변위 추정에 관하여)

  • Yoo, Jae-Ill;Hong, Jin-Kyu;Kwon, Hyo-Jung;Lim, Jong-Hwan;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.12 no.1
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    • pp.45-62
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    • 2010
  • Zero plane displacement (d) is the elevated height of the apparent momentum sink exerted by the vegetation on the air. For a vegetative canopy, d depends on the roughness structure of a plant canopy such as leaf area index, canopy height and canopy density, and thus is critical for the analysis of canopy turbulence and the calculation of surface scalar fluxes. In this research note, we estimated d at the Gwangneung coniferous forest by employing two independent methods of Rotach (1994) and Martano (2000), which require only a single-level eddy-covariance measurement. In general, these two methods provided comparable estimates of $d/h_c$ (where $h_c$ is the canopy height, i.e., ~23m), which ranged from 0.51 to 0.97 depending on wind directions. These estimates of $d/h_c$ were within the ranges (i.e., 0.64~0.94) reported from other forests in the literature but were sensitive to the forms of the nondimensional functions for atmospheric stability. Our finding indicates that one should be careful in interepreation of zero plane displacement estimated from a single-level eddy covariance measurement that is conductaed within the roughness sublayer.

Photosynthetic Characteristics and a Sensitive Indicator for $O_3$-exposed Platanus orientalis (오존에 노출된 버즘나무의 광합성 특성과 민감성 지표)

  • Lee Jae-Cheon;Oh Chang-Young;Han Sim-Hee;Kim Pan-Gi
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.3
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    • pp.220-226
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    • 2005
  • We investigated the effect of $O_3$ on the photosynthetic characteristics of oriental plane (Platanus orientalis L.) that is used as a side tree or ornamental tree in Korea. Two-year-old oriental plane seedlings were transplanted to pots and transferred into a closed $O_3$ chamber, Photosynthetic pigment content and photosynthetic characteristics of leaves were measured every three weeks during 100 ppb $O_3$ fumigation. There was no visible foliar injury by $O_3$ exposure and the content of photosynthetic pigments did not show significant differences between control and $O_3$-treated seedlings. But photosynthetic rate, stomatal conductance, and water use efficiency in leaves of $O_3$-treated seedlings were reduced after six weeks of ozone fumigation. In addition, reduction of carboxylation efficiency and photochemical efficiency was observed in leaves of $O_3$-treated seedlings after three weeks and six weeks. In accordance with our results, carboxylation efficiency, the most sensitive parameter to $O_3$ stress, was considered to be a suitable indicator of $O_3$ sensitivity.

EXISTENCE OF SPANNING 3-TREES IN A 3-CONNECTED LOCALLY FINITE VAP-FREE PLANE GRAPH

  • Jung, Hwan-Ok
    • Journal of applied mathematics & informatics
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    • v.28 no.3_4
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    • pp.893-908
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    • 2010
  • In this paper we prove the existence of spanning 3-trees in a 3-connected infinite locally finite VAP-free plane graph. Together with the results of Barnette and the author, this yields that every finite or infinite 3-connected locally finite VAP-free plane graph contains a spanning 3-tree.

Tomosynthesis Feasibility Study for Visualization of Interiors of Wood Columns Surrounded with Walls

  • LEE, Jun Jae;KIM, Chul-Ki
    • Journal of the Korean Wood Science and Technology
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    • v.50 no.4
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    • pp.246-255
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    • 2022
  • The need for non-destructive testing and evaluation of Korean traditional wooden buildings is increasing because of their widespread deterioration. Among all types of deterioration, termite damage in wooden columns is the most difficult to detect with the naked eye because it starts inside the wood, and the initial deterioration is small. X-ray computed tomography (CT) is the best technology to investigate the inner state of wood that has less damage, but applying it to wooden columns between walls is challenging. Therefore, the feasibility of tomosynthesis, which is a method to reconstruct a coronal section of a subject with a few X-ray projections from a limited angle of rotation, was studied as an alternative to CT. Pine (P. densiflora) with three artificial holes was prepared as a specimen to evaluate the quality of reconstructed tomosynthesis images according to the different number of projections. The quality of the tomosynthesis images in the in-focus plane was evaluated using the contrast-to-noise ratios, while a vertical resolution between the images was assessed by determining the artificial spread function. The quality of the tomosynthesis image in the in-focus plane increased as the number of projections increased and then remained constant as the number of projections reached 21 or over. In the case of vertical resolution, there was no significant difference when 21 projections or more were used to reconstruct the images. A distinct difference between coronal section images was found when the distance was more than 10 mm from one plane to another plane.

A Study on Prioritization of Urban Forest Composition Using Needs Analysis - Targeting Paju Heyri Village

  • Kang, Byong-Rho;Koo, Ja-Houng;Kim, Hyoung-Tae;Woo, Jong-Choon
    • Journal of Forest and Environmental Science
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    • v.34 no.1
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    • pp.87-94
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    • 2018
  • This study proposes a strategy for the creation and management of urban forests in Paju Heyri art village. Urban forest composition attributes (4 categories and 16 items) were extracted and the questionnaire was asked to the level and the current level for tourists, local residents and workers in Paju Heyri art village. And the priority order for the creation of urban forests was derived through the difference between the present level (performance) and the required level (importance) and the requirements analysis procedure. In this study, the priorities of each item of urban forest formation attributes were determined. The t-test alone had limitations, so we calculated the Borich needs which were not covered by the existing Importance - Performance Analysis (IPA). We used the Locus for Focus Model, which is a method for visually confirming the difference between the current level and the required value for the required level in the 4-quadrant coordinate plane. The results of this study show that the seven priorities can be used as a useful tool for the formulation of urban forests and operational strategies and can be a basic research for the activation of urban forests in the future.

Application of Drone Photogrammetry for Current State Analysis of Damage in Forest Damage Areas (드론 사진측량을 이용한 산림훼손지역의 훼손 현황 분석)

  • Lee, Young Seung;Lee, Dong Gook;Yu, Young Geol;Lee, Hyun Jik
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.3
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    • pp.49-58
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    • 2016
  • Applications of drone in various fields have been increasing in recent years. Drone has great potential for forest management. Therefore this paper is using drone for forest damage areas. Forest damage areas is divided into caused by anthropogenic and occurs naturally, the possibility of disasters, such as slope sliding, slope failures and landslides, sediment runoff exists. Therefore, this research was to utilize the drone photogrammetry to perform the damage analysis of forest damage areas. Geometrical treatment processing results in Drone Photogrammetry, the plane position error RMSE was ${\pm}0.034m$, the elevation error RMSE was ${\pm}0.017m$. The plane position error of orthophoto RMSE was ${\pm}0.083m$, the elevation error of digital elevation model RMSE was ${\pm}0.085m$. In addition, It was possible to current state analysis of damage in forest damage areas of airborne LiDAR data of before forest damage and drone photogrammetry data of after forest damage. and application of drone photogrammetry for production base data for restoration and design in forest damage areas.

SPANNING 3-FORESTS IN BRIDGES OF A TIGHT SEMIRING IN AN LV-GRAPH

  • Jung, Hwan-Ok
    • Journal of applied mathematics & informatics
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    • v.27 no.5_6
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    • pp.1307-1318
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    • 2009
  • An infinite locally finite plane graph is an LV-graph if it is 3-connected and VAP-free. In this paper, as a preparatory work for solving the problem concerning the existence of a spanning 3-tree in an LV-graph, we investigate the existence of a spanning 3-forest in a bridge of type 0,1 or 2 of a tight semi ring in an LV-graph satisfying certain conditions.

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