• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.53-60
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• 2002

Motion of lung tumors from respiration has been reported in the literature to be as large as of 1-2 cm. This motion requires an additional margin between the Clinical Target Volume (CTV) and the Planning Target Volume (PTV). While such a margin is necessary, it may not be sufficient to ensure proper delivery of Intensity Modulated Radiotherapy (IMRT) to the CTV during the simultaneous movement of the DMLC. Gated treatment has been proposed to improve normal tissues sparing as well as to ensure accurate dose coverage of the tumor volume. The following questions have not been addressed in the literature: a) what is the dose error to a target volume without gated IMRT treatment\ulcorner b) what is an acceptable gating window for such treatment. In this study, we address these questions by proposing a novel technique for calculating the 3D dose error that would result if a lung IMRT plan were delivered without gating. The method is also generalized for gated treatment with an arbitrary triggering window. IMRT plans for three patients with lung tumor were studied. The treatment plans were generated with HELIOS for delivery with 6 MV on a CL2100 Varian linear accelerator with a 26 pair MLC. A CTV to PTV margin of 1 cm was used. An IMRT planning system searches for an optimized fluence map ${\Phi}$ (x,y) for each port, which is then converted into a dynamic MLC file (DMLC). The DMLC file contains information about MLC subfield shapes and the fractional Monitor Units (MUs) to be delivered for each subfield. With a lung tumor, a CTV that executes a quasi periodic motion z(t) does not receive ${\Phi}$ (x,y), but rather an Effective Incident Fluence EIF(x,y). We numerically evaluate the EIF(x,y) from a given DMLC file by a coordinate transformation to the Target's Eye View (TEV). In the TEV coordinate system, the CTV itself is stationary, and the MLC is seen to execute a motion -z(t) that is superimposed on the DMLC motion. The resulting EIF(x,y)is inputted back into the dose calculation engine to estimate the 3D dose to a moving CTV. In this study, we model respiratory motion as a sinusoidal function with an amplitude of 10 mm in the superior-inferior direction, a period of 5 seconds, and an initial phase of zero.

• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.299-313
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• 2023

Stellaria pallida (Dumort.) Crép., S. ruderalis M. Lepší, P. Lepší, Z. Kaplan & P. Koutecký, and Cerastium pumilum Curtis are unrecorded alien species of Caryophyllaceae found in Seoul and Gyeonggi-do in the Republic of Korea. Stellaria pallida is readily distinguished from other taxa in the same genus by its petals, as it's considerably smaller than the sepals or absent. In contrast, S. ruderalis is difficult to identify as it has intermediate traits between S. media L. and S. neglecta (Lej.) Weihe. However, S. ruderlais clearly identified by seed morphology, and S. ruderalis, unlike S. media and S. neglecta, has conical shape of outer periclinal wall and papillate on the basely surface of that. Cerastium pumilum is similar to C. glomeratum Thuill. and belongs to the same subgenus (Sub gen. Fugacia); however, it has some distinct characteristics, including stamens that are primarily 8 (5-10), upper bracts with membranous edges, and the length of the pedicels and petals being longer than that of the sepals. The three of alien plants was recorded for the first time in this study, and information of their habitat, distribution map, description and photographs are presented.

• Journal of Wetlands Research
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• v.26 no.1
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• pp.51-61
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• 2024

This study was conducted to identify the community structure of two outstanding forest wetlands in Goheung-gun, Jeollanam-do, and to investigate their succession trends. vegetation survey was conducted using the Z-M phytosociological method From May to October, 2023, and based on this data, the Actual vegetation map was created by categorizing communities. This resulted in the classification of six communities. namely, Rhynchospora faberi community, Alnus japonica-Molinia japonica community, Ilex crenata-M. japonica community, M. japonica community, A. japonica-Pinus densiflora community and A. japonica community. The results of each layer's importance value (IV) analysis results indicated that in the R. faberi community, that of R. faberi, an obligate wetland plant, was high. In the subtree and shrub layers of the other five communities, A. japonica, a key species in wetland ecosystems, and Pinus densiflora and I. crenata, both obligate upland plants, exhibited higher IV. In the herb layer, the IV of M. japonica, a representative species of intermediate wetlands, was notably high. The results of classifying all observed plant species in the survey area based on their wetland preference revealed that in the R. faberi community, the occurrence rate of obligate wetland plants was high. However, in the other five communities, the occurrence rate of obligate upland plants was predominantly observed. Excluding the R. faberi community, in the other five communities constituting the outstanding forest wetlands, the occurrence rate of upland plants among the forest plants was high. It was observed that M. japonica which typically appears during the transition of wetlands to drier stages, was flourishing, indicating that the wetland was undergoing vegetation succession and terrestrialization.

• Korean Journal of Environment and Ecology
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• v.31 no.3
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• pp.318-328
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• 2017

In order to provide basic data for the ecological management of forest vegetation in Southern Naeyeon Mountains, A total of 149 sample plots were selected and vegetation survey was carried out by the phytosociological method of the ZM school to classify vegetation types and to grasp ecological characteristics. The forest vegetation was divided into 10 types in terms of species composition, and had a unit hierarchy of 2 community groups, 4 communities, 6 sub-communities and 6 variants. A total of 19 types of physiognomic vegetation were identified based on uppermost dominant species, of which 18 were natural vegetation and 1 was artificial vegetation. As a result of the analysis of the importance values of constituent species, Quercus mongolica, a potentially natural vegetation element, was found to be relatively more important in most stands than other species, and excluding the artificial interference, most of the areas except for some sites would be changed to Q. mongolica forest. In order to understand the spatial distribution of forest vegetation, 1/5,000 large-scale physiognomic vegetation map was created by the uppermost dominant species. As a result, natural vegetation accounted for 98.2%, the number of vegetation patches was 733 and the average area per patch 3.93ha.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.5
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• pp.1-12
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• 2019

It is important to measure the height of trees as an essential element for assessing the forest health in urban areas. Therefore, an automated method that can measure the height of individual tree as a three-dimensional forest information is needed in an extensive and dense forest. Since airborne LiDAR dataset is easy to analyze the tree height(z-coordinate) of forests, studies on individual tree height measurement could be performed as an assessment forest health. Especially in urban forests, that adversely affected by habitat fragmentation and isolation. So this study was analyzed to measure the height of individual trees for assessing the urban forests health, Furthermore to identify environmental factors that affect forest growth. The survey was conducted in the Mt. Bongseo located in Seobuk-gu. Cheonan-si(Middle Chungcheong Province). We segment the individual trees on coniferous by automatic method using the airborne LiDAR dataset of the two periods (year of 2016 and 2017) and to find out individual tree growth. Segmentation of individual trees was performed by using the watershed algorithm and the local maximum, and the tree growth was determined by the difference of the tree height according to the two periods. After we clarify the relationship between the environmental factors affecting the tree growth. The tree growth of Mt. Bongseo was about 20cm for a year, and it was analyzed to be lower than 23.9cm/year of the growth of the dominant species, Pinus rigida. This may have an adverse effect on the growth of isolated urban forests. It also determined different trees growth according to age, diameter and density class in the stock map, effective soil depth and drainage grade in the soil map. There was a statistically significant positive correlation between the distance to the road and the solar radiation as an environmental factor affecting the tree growth. Since there is less correlation, it is necessary to determine other influencing factors affecting tree growth in urban forests besides anthropogenic influences. This study is the first data for the analysis of segmentation and the growth of the individual tree, and it can be used as a scientific data of the urban forest health assessment and management.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.667-670
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• 2005

Ground control points(GCPs) can be extracted from SAR data given precise orbit for DTM generation using optic images and other SAR data. In this study, we extract GCPs from ERS SAR data and SRTM DEM. Although it is very difficult to identify GCPs in ERS SAR image, the geometry of optic image and other SAR data are able to be corrected and more precise DTM can be constructed from stereo optic images. Twenty GCPs were obtained from the ERS SAR data with precise Delft orbit information. After the correction was applied, the mean values of planimetric distance errors of the GCPs were 3.7m, 12.1 and -0.8m with standard deviations of 19.9m, 18.1, and 7.8m in geocentric X, Y, and Z coordinates, respectively. The geometries of SPOT stereo pair were corrected by 13 GCPs, and r.m.s. errors were 405m, 705m and 8.6m in northing, easting and height direction, respectively. And the geometries of RADARS AT stereo pair were corrected by 12 GCPs, and r.m.s. errors were 804m, 7.9m and 6.9m in northing, easting and height direction, respectively. DTMs, through a method of area based matching with pyramid images, were generated by SPOT stereo images and RADARS AT stereo images. Comparison between points of the obtained DTMs and points estimated from a national 1 :5,000 digital map was performed. For DTM by SPOT stereo images, the mean values of distance errors in northing, easting and height direction were respectively -7.6m, 9.6m and -3.1m with standard deviations of 9.1m, 12.0m and 9.1m. For DTM by RADARSAT stereo images, the mean values of distance errors in northing, easting and height direction were respectively -7.6m, 9.6m and -3.1m with standard deviations of 9.1m, 12.0m and 9.1m. These results met the accuracy of DTED level 2

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.2001-2011
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• 1993

This study deals with the machining of sculptured surfaces on 5-axis CNC milling machine with end mill cutter. The study (I) has the following contents. In 5-axis CNC milling, CL-data consist of CC-data and cutter axis direction vector at the CC-point. Thus, in machining of the sculptured surface on 5-axis CNC milling machine, determination of the direction vector of the milling cutter is very important. The direction vector is obtained by the fact that bottom plane of the milling cutter must not interfere with the free-form surface being machined. The interference is checked by the z-map method which can be applied in all geometric types of the sculptured surfaces. After generating NC part programs from 5-axis post-processing algorithms, sculptured surfaces were machined with 5-axis CNC milling machine (CINCINNATI MILACRON, 20V-80). From these machining tests, it was shown that the machining of the free-form surfaces on 5-axis CNC milling machine with the end mill has smaller cusp heights and shorter cutting time than on 3-axis CNC milling machine with the ball-end mill. Thus, 5-axis CNC end milling was effective machining method for sculptured surfaces. The study (II) deals with the prediction of cusp height and the determination of tool path interval for the 5-axis machining of sculptured surfaces on the basis of study(I).

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.365-370
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• 2009

The aim of this study was to investigate the vegetation types of Minarimot, in Jeju Islands. The vegetation types were classified by the Z-M school method and cluster analysis. The vegetation in Minarimot was classified into 6 communities and 2 subcommunities: Persicaria thunbergii-Isachne globosa community (vegetation type: A), Scirpus tribangulatus-Eleocharis manillata var. cyclocarpa community (B) (Aneilema keisak subcommunity (B-1) and Caldesia parnassifolia-Potamogeton distinctus subcommunity (B-2)), Eleocharis kuroguwai community (C), Phragmites communis community (D), Scirpus tabernaemontani community(E) and Typha orientalis community (F). These communities were grouped into three main categories according to cluster analysis. The community (A) established at the edge of the wetland which has the driest condition was distinguished as Group I, while the community (B) emerged in the submerged zone was distinguished as Group III. The Group II was designated as the communities (C, D, E, F) between Group I and III, whose communities were occasionally submerged. The result of principal coordinate analysis (PCoA) appeared that the different vegetation established along the wetland were depending on water environment such as water depth and the period submerged.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.6
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• pp.62-76
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• 2001

This study is to offer the basic information and materials for the restoration of the urban forest and the ecologically healthy and continuous green belt through the investigation and the analysis on the vegetation in Hwasan Park, Chonju-City. The flora of Hwasan Neighborhood park was composed of 86 families 230 genera, 261 species, 35 varieties, 1 formae or 298 Taxa. Among them, calculation of Pte-Q Index represented 0.60, Fisher's Index. Some characteristics of the plants in this area have represented such as Th-D1-R5 type in biological type, erect form(64.6%) in growth type, 30 taxa in naturalized plants. The life form spectra investigated from Hwasan neighborhood park was recognized as the following M"17.4%, N:11.4%, E:0.3%, Ch:0%, H:29.8%, G:6.7%, HH:0%, Th:34.2%. By the Z-M method 5 plant communities and 3 afforestation were recognized; Quercus variabilis community, Q.acutissima community, Q.serrata community, Sorbus alnifolia community, Pinus densiflora community, P.rigida afforestation, Robinia pseudo-acacia afforestation and Larix leptolepis afforestation. The actual vegetation map constructed on the grounds of the communities classified and other data. The pattern of successional trend of tree species might be suggested: L. leptoleipis, P. rigida and P. densifloralongrightarrowQ.variabilis and Q.acutissimalongrightarrowS.alnifolia and Q.serratalongrightarrowCarpinus tschonoskii community. Three measurements of species diversity (richness index(SR), Shannon-Wiener index(H'), evenness index(J')) and their relationship with community type were studied in the surveyed plant communities. Q.serrata community was higher in SR, H', J' than the other communities, whereas R.pseduo-acacia afforestation was low. Finally, The vegetation of the Hwasan neighborhood park must not allowed any more. Nothing ca be better than native states in preserving the ecosystems.tems.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.56-63
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• 1985

We have characterized the plasmids of zymomonas, and constructed E. coli-Zymomonas shuttle vector. Plasmids have been detected in four strains of Zymomonas mobilis. All strains tested had at least one plasmid ranging in size from about 1.7 to 46kb. Antibiotics resistances of Z. mobilis were tested to select the host strain. All strains were very sensitive to tetracycline and chloramphenicol. Homology tests between the plasmids in four strains showed that the plasmids of ATCC10988 is highly homologous to those of ZM1, and that there is no homology between plasmids of ZM4 and Agll. The 1.7kb plasmid of ATCC10988, named as pZM886, also has no homology with plasmids of ZM4. A hybrid plasmid, designated to pBZ41, was constructed from pZM886 and pBR322. A restriction map of pBZ41 was established. Replicon of pZM886 didn't operate in E.coli and pBR322 seemed not to replicate in Zymomonas. pBZ41 was transfered from E. coli to Zymomonas by conjugal mobilization. The transconjugants were resistant to tetracycline and maintained pBZ41 stably.