• Journal of Forest and Environmental Science
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• v.40 no.1
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• pp.24-34
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• 2024

Fire, being primarily a natural phenomenon, is impossible to control, although it is feasible to map the forest fire risk zone, minimizing the frequency of fires. The spread of a fire starting in any stand in a forest can be predicted, given the burning conditions. The natural cover of the land and the safety of the population may be threatened by the spread of forest fires; thus, the prevention of fire damage requires early discovery. Satellite data and geographic information system (GIS) can be used effectively to combine different forest-fire-causing factors for mapping the forest fire risk zone. This study mainly focuses on mapping forest fire risk in the Madikhola watershed. The primary causes of forest fires appear to be human negligence, uncontrolled fire in nearby forests and agricultural regions, and fire for pastoral purposes which were used to evaluate and assign risk values to the mapping process. The majority of fires, according to MODIS events, occurred from December to April, with March recording the highest occurrences. The Risk Zonation Map, which was prepared using LULC, Forest Type, Slope, Aspect, Elevation, Road Proximity, and Proximity to Water Bodies, showed that a High Fire Risk Zone comprised 29% of the Total Watershed Area, followed by a Moderate Risk Zone, covering 37% of the total area. The derived map products are helpful to local forest managers to minimize fire risks within the forests and take proper responses when fires break out. This study further recommends including the fuel factor and other fire-contributing factors to derive a higher resolution of the fire risk map.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.344-350
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• 2018

This study was carried out to improve the forest management method considering the use of high value added timber in the natural broadleaf forests. For this purpose, the criteria for evaluating the quality grade of standing trees were established and applied to the oak stand in the central region of Korea. The evaluation factors of the grade were bending of stem, branch, stem damage, and other defects. If the logs are divided into 2.1 m units and three logs up to 6.3 m are available, they are classified as Grade I (G-I). If two logs are available, they are classified as Grade II (G-II), If only one log is available, it is classified as Grade III (G-III). When any log is not available as timber, it is classified as Grade IV (G-IV). As a result of applying the grade to the oak stand, G-I was 6.7 %, G-II was 28.0 %, G-III was 38.3 %, and G-IV was 27.0 %. The ratio of standing trees by oak species of higher than G-III was 88.2 % for Quercus acutissima, 88.1 % for Q. variabilis, 83.5 % for Q. serrata, 56.3 % for Q. aliena, and 50.3 % for Q. mongolica, respectively. The G-IV ratio for Q. variabilis and Q. mongolica tended to decrease with increasing diameter at breast height. The order of major defect affecting the grading level was bending of stem > branch > stem damage > other defects. Considering the grade level and oak species distribution, it was concluded possible to produce high quality hardwood timber when we concentrate forest tending techniques on Q. acutissima and Q. variabilis stand. In order to improve the accuracy of grading, it is necessary to continuous complement through the monitoring research for evaluation factors.

• Environmental Mutagens and Carcinogens
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• v.8 no.1
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• pp.1-12
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• 1988

The effects of aphidicolin (APC), an inhibitor of DNA polymerase alpha, or 2', 3'-dideoxythymidine 5'-triphosphate (ddTTP), an inhibitor of DNA polymerase beta, on the repair of DNA damage induced by ethyl methanesulfonate (EMS) or bleomycin (BLM) were investigated in Chinese hamster ovary (CHO)-K1 cells. Three assays were employed in this study: unscheduled DNA synthesis, alkaline elution and alkaline sucrose gradient sedimentation. It was shown that APC or ddTTP inhibited DNA induced by EMS, and thus, the post-treatment with APC or ddTTP following EMS treatment was resulted in the more amount of unscheduled DNA synthesis, and the more accumulation of DNA single-stand breaks than the cells post-incubated without APC or ddTTP. While, in the BLM induced DNA repair, only ddTTP inhibited DNA repair induced by BLM. And thus, the groups post-incubated with or without APC after BLM treatment had the same value in the amount of unscheduled DNA synthesis and of DNA single-strand breaks, while post-treatment with ddTTP was resulted in the increased amount of unscheduled DNA synthesis and the increased DNA sin -strand breaks than the group without ddTTP. These results suggested that both of DNA polymerase $\alpha$ and $\beta$ participated in the repair of DNA damage induced by EMS, but in BLM-induced DNA repair, polymerase $\beta$ participated.ipated.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.48-53
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• 1984

Using the Duff and Noland's method, the annual ring growth patterns of the red pine in the natural stands were examined at two locations; Seocheon, Chungnam-do where the stand had been infested with the pine needle gall midge, Thecodiplosis japonensis, during the years from 1975 to 1978, and Hongsong, Chungnam-do where had been no incidence of the insect damage. The results obtained are as follows: 1) With the normal red pine of 13 year old, the growth pattern in the oblique sequence indicates that the annual growth rates are maximum at the few terminal internodes, and decrease gradually with the downward internodes. Such characteristic of the growth pattern is not clear in the horizontal sequence of annual rings. 2) The indications of the radial growth reduction of the pine tree due to the pine gall midge infestation could be examined with any of three series at the crown level internodes; horizontal, vertical and oblique series. For the basal internodes, however, the horizontal series appeared to be inadequate for the analysis of the damage impact because it seemed to be masked by various factors other than direct effects of the damage. 3) Of the three ways of radial growth analyses, oblique sequence seems to be the most usefull, especially for the detection of the impact on growth caused by incipient or light infestation.

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1291-1302
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• 2020

To verify the field-effectiveness of Terrestrial Laser Scanner (TLS), a terrestrial LiDAR was deployed to examine the damage properties of woods in forest fire area, then the data was compared with the results surveyed by a forestry expert. Four sample plots (30 m × 50 m, 0.15 ha) were set from the foot to the top of the mountain, and DBH, height, clear length, burned height, and crown length were investigated. Next, TLS collected information on damage characteristics found in the sample plots. This information was then compared with that amassed by the expert. The expert and the TLS survey results showed 30.8 cm and 29.9 cm for DBH, 15.8 m and 17.5 m for tree height, 8.4 m and 8.4 m for clear length, 4.0 m, 3.5 m for burned height, and 7.4 cm and 9.1 cm for crown length. With the exceptions of height and clear length, no notable discrepancy was observed between two methods. H/D ratio, CL/H ratio, and BH/CL ratio, all of which contribute to stability and decay rate of the stand, from the two methods were also compared. The human survey rated each ratio (H/D, CL/H, BH/CL in order) 51.3%, 47.1%, and 53.6%, while the TLS presented the results of 58.8%, 52.0%, and 38.7%.

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.259-270
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• 2020

Extreme weather events, such as heat and drought, have occurred frequently over the past two decades. This has led to continuous reports of cases of forest damage due to physiological stress, not pest damage. In 2014, pine trees were collectively damaged in the forest genetic resources reserve of Sogwang-ri, Uljin, South Korea. An investigation was launched to determine the causes of the dieback, so that a forest management plan could be prepared to deal with the current dieback, and to prevent future damage. This study aimedto 1) understand the topographic and structural characteristics of the area which experienced pine tree dieback, 2) identify the main causes of the dieback, and 3) predict future risk areas through the use of machine-learning techniques. A model for identifying risk areas was developed using 14 explanatory variables, including location, elevation, slope, and age class. When three machine-learning techniques-Decision Tree, Random Forest (RF), and Support Vector Machine (SVM) were applied to the model, RF and SVM showed higher predictability scores, with accuracies over 93%. Our analysis of the variable set showed that the topographical areas most vulnerable to pine dieback were those with high altitudes, high daily solar radiation, and limited water availability. We also found that, when it came to forest stand characteristics, pine trees with high vertical stand densities (5-15 m high) and higher age classes experienced a higher risk of dieback. The RF and SVM models predicted that 9.5% or 115 ha of the Geumgang Pine Forest are at high risk for pine dieback. Our study suggests the need for further investigation into the vulnerable areas of the Geumgang Pine Forest, and also for climate change adaptive forest management steps to protect those areas which remain undamaged.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.33-39
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• 1985

This study was performed to investigate the damage to the primary production of Pinus thunbergii forest from air pollution around the Yeochon Industrial Estate. The data were observed at 6 sites in the vicinity of the above area. The vitality of pine trees and the accumulation of the soluable sulfur and the fluorine were analyzed. Their value was generally increased near the source of air pollutants. The biomass density and annual net production were $1.01kg/m^3$, 5.90 t/ha/yr in the stand 4 respectively and $0.66kg/m^3$, 0.32t/hr/hr in the stand 3 respectively. The net assimilation rate was 0.4 - 1.6 kg/kg/yr and the efficiency of leaf to produce stem was 0.3 - 1.3 kg/kg/yr. The annual growth percentage of volume was 16.0% at the slightly damaged area and 4.0% at the severly damaged area. The maximum mean annual increment per tree was $0.0040m^3$ and $0.0008m^3$ in same order.

• Convergence Security Journal
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• v.2 no.2
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• pp.199-207
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• 2002

Comes in into recent times and there is on with a level where the attack against the computer virus and the hacking which stand is serious. The recently computer virus specific event knows is the substantial damage it will be able to occur from our life inside is a possibility of feeling. The virus which appears specially in 1999 year after seemed the change which is various, also the virus of the form which progresses appeared plentifully The part virus does it uses the password anger technique which relocates the cord of the oneself. Hereupon consequently the vaccine programs in older decode anger to do the password anger of the virus again are using emulation engine. The password anger technique which the like this virus is complicated and decode anger technique follow in type of O.S. and the type is various. It uses a multi emulation engine branch operation setup consequently from one system and to respect it will be able to use a multiple operation setup together it will use the VMware which is an application software which it does as a favor there is a possibility where it will plan 'Virus Test Simulation' and it will embody.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.427-434
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• 2017

Recently, awareness of the public about the explosion damage has increased due to the increased risk of terrorism. The criteria for blast-resistance design is not sufficient in Korea, it is necessary to develop blast-resistance design for the stability and safety of building by static analysis of current blast-resistance design. In addition, as the increase of earthquake occurrence necessitates the seismic design, it is studied to judge the blast-resistance performance of members applying seismic design without blast-resistance design. Currently, the general analysis of blast load is to refer to UFC 3-340-02 manual. Blast-resistance performance was studied by applying characteristics of blast load through UFC 3-340-02 manual, beam converted into equivalent SDOF System. It is proved that blast-resistance performance is improved when seismic detail is applied considering the maximum deflection of normal, intermediate, and special moment frames.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.213-220
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• 2015

This study was carried out to determine the distribution of factors as effected by debris flow in Ulsan and Pusan metropolitan areas because mainly debris flow caused by typhoons and local heavy rainfall events is mainly attributed to damage of human being ad property. The high risk degree of debris flow was to affected by east (20%), northeast (20%) and northwest (20%) slopes with stand age class with elevation (69%) of 100-200 (33%). Also, the risk was high in high erosion collapse degree with slope degree of $20-25^{\circ}$ with over 300 mm (100%) of maximum daily rainfall events and 50-100 mm (50%) or >100 mm (50%) of maximum hourly rainfall events with <5 km of stream path and <50 ha of catchment area. Landslide debris and wood residue flow was also related to igneous rocks (73%) and bank collapse types of debrs flow (57%).