• Fire Science and Engineering
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• v.13 no.1
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• pp.31-36
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• 1999

This paper contained an actual investigation of a wildfire which broke out on 23 April R 1996 in Go-sung Kun, Kang-won Do examined the calories and the total calories of the m main trees which were Quercus variabillis and Pinus densiflora. There were three important f fire spread factors which were weather condition, fuel condition and terrain. The weather c condition was the most dangerous alarm level. The fuel condition having a high calory v value, Pinus densiflora made up 63% of the forest. Terrain of the forest were mostly c covered by steep slopes and complicated line construction. This experimental calorie study a about Pinus densiflora and Quercus variabillis showed that Pinus densiflora had 13,34kcal/g a and Quercus variabillis had 9.64kcal/g. In the case of weight loss of pyrolysis, Pinus densiflora had a higher percentage rated 35.71~10.05% than Quercus variabillis. Accordingly, Pinus densiflora showed lower than Quercus variabillis in heat resistance.

• Journal of Korean Society of Forest Science
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• v.73 no.1
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• pp.63-69
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• 1986

In general, the snow injury in forestry is an unusual disaster. The degree of snow injury varies greatly depending on stand density and the local topography. This study was conducted to investigate the snow injury in analyzing the demaged by snow-fall in Jinju, Gyeongsangnamdo. The results obtained were summarized as follow; Among 466 total damaged trees, 425 trees were broken and 41 trees were uprooted, the ratio of damage were 5.22%, 2.49%, 0.92% and 0.2% for Pinus densiflora, Pinus thunbergii, Pinus rigida, Alnus hirsuta respectively. The 95% of the damage trees were in the range of 3 to 11 m for height and in the range of 3 to 20 cm for D. B. H.. The directions of the damage trees had a large influence by direction of the wind, but they shown at high tendency to aspect of the slope relatively. The 82% of the damaged trees ranged from 11 to 24 age. The ratio of broken height ($H_B/H$) indicated that the damage was most frequent in the part of stem as 24%, 45%, 31% in the part of the root collar (0.1), stem (0.2-0.4), crown (0.5-1.0) respectively. In general, trees with stem-form coefficient ($H_B/D$) over 0.7-0.8 are apt to suffer by snow damage. The average of stem-form coefficient of trees in this area was 1.06. Therefore, the ratio of damage was high tendency as 3.14%. These results indicate that it is necessary to apply pertinent tending which will increase in resistance of snow damage. As avalanches from the flank of soil erosion rise in an importance matter in present, it should also be considered to measures for prevention and restoration.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.145-151
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• 1997

Purpose : To evaluate the loss of bone mineral contents(BMC) in lumbar spine within the radiation field for cervical cancer treatment, BMC in the irradiated patient group was compared with that of a normal control group. Method and materials : Measurements of BMC in the trabecular bone in lumbar spines(L3-L5) were performed in the both patient and normal control groups. Investigators used dual-energy quantitative computerized tomography(DEQCT) using Photon energy of 120 and 80kVp, The numbers of Patient and control groups were 43 in each with age distribution of fifth to seventh decade of women. The numbers of control group were 22 in fifth, 10 in sixth and 11 in seventh decade, those of patient group were 14 in filth, 14 in sixth, and 15 in seventh decade of women. The radiation field was extended to L5 spine for Pelvic irrdiation with 45-54Gy of external radiation dose and 30Gy of high dose rate brachytherapy in cervical cancer, Results : The BMC is decreased as increasing age in both control and patient groups. BMC in lumbar spine of patient group was decreased by about $13\%\;to\;40\%$ maximally. The BMC of L3 and L4 a region that is out of a radiation field for the Patient group demonstrated $119.5\pm30.6,\;117.0\pm31.7\;for\;fifth,\;83.3\pm37.8,\;88.3\pm46.8\;for\;sixth\;and\;61.5\pm18.3,\;56.2\pm26.6mg/cc$ for seventh, Contrasted by the normal control group has shown $148.0\pm19.9,\;153.2\pm23.2\;for\;fifth,\;96.1\pm30.2,\;105.6\pm26.5\;for\;sixth\;and\;73.9\pm27.9,\;77.2\pm27.2mg/cc$ for seventh decade, respectively The BMG of patient group was decreased as near the radiation field, while the lower lumbar spine has shown more large amounts of BMC in the normal control group. In Particular, the BMC of L5 within the radiation field was significantly decresed to $33\%,\;31\%,\;40\%$ compared with the control group of the fifth, sixth and seventh decades, respectively. Conclusion : The pelvic irradiation in cervical cancer has much effected on the loss of bone mineral content of lumbar spine within the radiation field, as the lower lumbar spine has shown a smaller BMC in Patient group with Pelvic irradiation in contrast to that of the normal control groups.

• Progress in Medical Physics
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• v.25 no.1
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• pp.15-22
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• 2014

The IMRT is proper implement to get high dose deliver to tumor as its shape and selective approach in radiation therapy. Since the IMRT is performed as modulated the radiation fluence by the MLC created the open shapes and its irradiation time, the dose of segment of radiation field effects on the cumulated portal dose. The accurate output factor of small and step shape of segment is important to improve the determination of deliver tumor dose as it is directly proportional to dose. This experiment performed with the 6 MV photon beam of Clinac Ex(Varian) from $3{\times}3cm^2$ to $0.5{\times}0.5cm^2$ small field size for collimator jaw in MLC free and/or for MLC open field in fixed collimator jaw $10{\times}10cm^2$ using the CC01 ion chamber, SFD diode, diamond detector and X-Omat film dosimetry. As results of normalized to the reference field of $10{\times}10cm^2$ of MLC, the output factor of $3{\times}3cm^2$ showed $0.899{\pm}0.0106$, $0.855{\pm}0.0106$ for $2{\times}2cm^2$, $0.764{\pm}0.0082$ for $1{\times}1cm^2$ and $0.602{\pm}0.0399$ for $0.5{\times}0.5cm^2$. The output factor of MLC open field has shown a maximum 3.8% higher than that of the collimator jaw open field.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.137-145
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• 1992

Three-dimensional dose calculations based on CT images are fundamental to stereotactic radiosurgery for small intracranial tumor. In our stereotactic radiosurgery program, irradiations have been performed using the 6 MV photon beam of linear accelerator after stereotactic CT investigations of the target center through the beam's-eye view and the coordinates of BRW frame converted to that of radiosurgery. Also we can describe the tumor diameter and the shape in three dimensional configuration. Non-coplanar irradiation technique was developed that it consists of a combination of a moving field with a gantry angle of $140^{\circ}$, and a horizontal couch angle of $200^{\circ}C$ around the isocenter. In this radiosurgery technique, we provide the patient head setup in the base-ring holder and rotate around body axis. The total gantry moving range shows angle of 2520 degrees via two different types of gantry movement in a plane perpendicular to the axis of patient. The 3-D isodose curves overlapped to the tumor contours in screen and analytic dose profiles in calculation area were provided to calculate the thickness of $80\%$ of tumor center dose to $20\%$ of that. Furtheremore we provided the 3-D dose profiles in entire calculation plane. In this experiments, measured isodose curves in phantom irradiation have shown very similiar to that of computer generations.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.1
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• pp.40-46
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• 2014

Treacher Collins syndrome (TCS) is autosomal dominant disorder that occurs approximately 1 in 25,000 to 50,000 live births. The main signs of syndrome are hypoplasia of facial bone and microtia. One in third of them is associated with cleft palate and often shows dental hypoplasia. TCS patients need several number of surgery with general anesthesia throughout their life time for recovery of function and esthetic. Endotracheal intubation of TCS patient is very difficult due to microstomia, retrognathia, choanal stenosis, and decreased oropharyngeal airway. Therefore, general anesthesia of adolescent TCS patient with immature incisor roots has high risk of causing dental trauma. This case is regarding TCS patient who was referred to the Department of Pediatric Dentistry, Yonsei University for avulsed upper left central incisor during endotracheal intubation. The purpose of this report is to emphasize the usefulness of mouth guard to prevent dental trauma when endotracheal intubation is needed for TCS patient.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.1
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• pp.10-18
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• 2017

Korean Red Pine (Pinus densiflora) has been protected and used as the most ecologically and socio-culturally important tree species in Korea. However, as dieback of Korean red pines has occurred in the protected area of the forest genetic resources. The aims of this study is to identify causes for dieback of pine tree by investigating topographical characteristics of pine tree dieback and its correlation to meteorological factors. We extracted the dead trees from the time series aerial images and analyzed geomorphological characteristics of dead tree concentration area. As a result, 1,956 dead pine trees were extracted in the study region of 2,600 ha. Dieback of pine trees was found mostly in the areas with high altitude, high solar radiation, low topographic wetness index, south and south-west slopes, ridgelines, and high wind exposure compared to other living pine forest area. These areas are classified as high temperature and high drought stress regions due to micro-climatic characteristics affected by topographic factors. As high temperature and drought stress are generally increasing with climate change, we can evaluated that a risk of pine tree dieback is also increasing. Based on these geomorphological characteristics, we developed a pine tree dieback risk map using Maximum Entropy Model (MaxEnt), and it can be useful for establishing Korean red pine protection and management strategies.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.47-58
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• 2012

This study was carried out to develop assessment model for the optimal site prediction of Dendropanax morbifera, Evergreen broad-leaved trees in warm temperate zone according to climate change. It was created criterion for assessment model of the optimal site prediction by quantification method to possible analysis of quantitative and qualitative data, through study relationship between growth of tree and site environmental factors. A program of the optimal site prediction was developed using program version 3.2, an Avenue and Dialog Designer tool of ESRI as GIS(geographic information system) engine. Developed program applied to test accuracy of the optimal site prediction in study area of Wando, Jeollanam-do, having a various evergreen broad-leaved trees of warm temperate zone. In the results from analysis of the optimal site prediction on Dendropanax morbifera, the characteristics of optimal site were analyzed site environmental features with 401~500m of altitude, $15^{\circ}$ of slope, hillside of local topography, alluvium of deposit type, convex of slope type and south of aspect. The mapping area per grade of the optimal site prediction in the Dendropanax morbifera showed 1,487.2ha(25.4%) of class I, 1,020.3ha(17.4%) of class II, 2,231.8ha(38.2%) of class III and 1,110.5ha(19.0%) of class IV.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.5
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• pp.1-12
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• 2023

This study evaluated the overturning stability of portable tripod ladders used for high-altitude work such as tree management and pruning work in landscaping construction and management. Portable tripod ladders, which are included in general mobile or portable ladders frequently used in industrial sites, are supported in a triangular support structure, not a 4-point support like common A-type Ladders. In addition, since the working height is more than twice that of a mobile or portable ladder, the possibility of an overturning accident that threatens the safety of workers with a fall accident is high. Therefore, based on the overturning stability test specified in ANSI-ASC A14.7 and EN 131-Part 7, which are related standards for about 130 types of portable tripod ladders sold and used in Korea. An equation to calculate each moment according to working height was derived. Then, each calculated moment was compared to evaluate the safety factor for overturning and stability. As a result of the overturning stability evaluation according to each standard, when the provisions of EN 131-Part 7 were applied, portable tripod ladders with 8 steps in the rear direction and 6 steps or more in the side direction were evaluated as unstable against overturning, but according to ANSI-ASC A14.7 regulations. It was evaluated that the stability against overturning was secured in all directions and number of steps.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.3
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• pp.117-128
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• 2023

Tree dieback in Geumgang pine forest has occurred in Uljin and Bonghwa since the 2010s. In order to identify status of tree dieback and prevent further damages, a monitoring project for tree dieback in Geumgang pine forest had been launched by Southern regional office of forest service in 2020. This study was conducted to understand the characteristics of tree dieback occurrence and assess the high risk areas using the occurrence data in the project. Pine tree dieback occurred frequently in areas with mountain ridges in high elevation, dry south-facing slopes, mature stands, and high temperature rise in winter. Furthermore, the result of risk assessment showed that 6.2 percent(5,294ha) of Geumgang pine forest(85,000 ha) in total study area are at high risk of tree dieback. As the pine trees in the high risk area are prone to experience the dieback due to temperature and drought-related extreme weather events, regular forest management activities are needed to reduce the drought stress of pine trees. Forest health management for the pine forest with high protection priority can be also useful strategy to counter the risk of decline. This results can be used as the basic information for the adaptive forest management to climate change.