• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.5
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• pp.425-430
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• 1992

This experiment was carried out to collect the Korean red rices and to evaluate them as useful germplasm, 1,113 lines of weedy red rices were collected from farmer's field of the Korean peninsula from 1988 to 1991. The collected red rices were classified into two groups : One was long grain type with length /width ratio of 3.01$\pm$0.11 in paddy rice and the other was short grain type with length /width ratio of 2.28$\pm$0.12. Among the collected red rices 289 lines were long grain type and 824 lines were short. The red rices of long grain type were distributed in Nagdong and Seomjin river vallies of the southern part of the Korean peninsula, and the short ones were distributed all around of the peninsula. Among the collected long grain type red rices, 90.8% was red and 9.2% was white, and among the short grain type 88.8% was red, 10.6% was brown and 0.6% was white in pericarp color. 9.3% of the long grain type and 30.7% of the short grain type of the Korean red rices reacted to phenol solution. In the short grain type, 4.3% was waxy grained, but no waxy line was found in the long grain type. All the long grained Korean red rice showed easy shattering and no awn, however in the short grained red rices, 85.2% showed easy shattering and 49.6% was awned.

• Microbiology and Biotechnology Letters
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• v.10 no.2
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• pp.133-144
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• 1982

The distribution of acid phosphatase activity was investigated with 141 microorganisms from the type culture collection of Chong Kun Dang laboratory and the 41 strains isolated from natural sources. The phytase activity was detected mainly with fungal strains. A fungus isolated from soil and identified as Aspergillus niger had shown the highest phytase activity. The environmental conditions for the enzyme formation by the isolate and some properties of the enzyme were also studied. The results obtained were as follows: (1) The highest phytase production was observed when the fungus was cultivated at 28$^{\circ}C$ for 5 days in the corn starch based medium using the cells incubated at 34$^{\circ}C$ for 3 days as a seed. (2) The optimal initial pH of the culture medium was found to around 2 for the formation of phytase. (3) Sucrose was proved to be one of the most effective carbon sources tested for the enzyme production. (4) As an inorganic nitrogen source, potassium nitrate was found to give a good result in the production of phytase. (5) Synthesis of phytase was significantly increased by the supplement with 0.2 % corn steep liquor to the basal medium as an organic nitrogen source. (6) At the concentration of 40-80 mg inorganic phosphate per liter of the culture medium, the enzyme formation revealed the highest level. But as the phosphate was increased above this optimum concentration the phytase activity was drastically decreased although the cell density showed to be still increasing

• Korean Journal of Plant Taxonomy
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• v.45 no.3
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• pp.213-220
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• 2015

To elucidate the origin and patterns of establishment of insular plants on Ulleungdo Island, maternally inherited chloroplast DNA, which is useful for tracing seed movements, was used. Fagus multinervis, an endemic species that dominated broadleaf deciduous forests on Ulleungdo Island, is an excellent model for such a study. To understand the diversity and spatial distribution of the chloroplast haplotypes of F. multinervis, nucleotide sequences of the psbA-trnH region were determined from 144 individuals sampled throughout the island. Results of a phylogenetic analysis of the region with close relatives of F. multinervis suggest that F. multinervis is sister to a clade of F. japonica and F. engleriana. No haplotype variation was found within F. multinervis. This remarkably low cpDNA haplotype diversity is in contrast to the findings of previous allozyme studies of F. multinervis populations that showed high genetic diversity on Ulleungdo Island. Repeated colonization during the early stage of establishment via birds that migrated from a source area where the F. multinervis cpDNA haplotype was geographically structured may have resulted in the observed pattern of haplotype diversity. Alternatively, long-distance dispersal of seeds of the progenitor of F. multinervis via birds or typhoons to Ulleungdo may have been a single event, whereas the immigration of pollen from the mainland likely occurred frequently. Comparative phylogeographic studies of other species endemic to Ulleungdo Island and their close relatives on the neighboring mainland are necessary for a more complete understanding of the evolution of the island's native species.

• Radiation Oncology Journal
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• v.29 no.3
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• pp.199-205
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• 2011

Purpose: The present study compared the difference between intraoperative transrectal ultrasound (iTRUS)-based prostate volume and preplan computed tomography (CT), preplan magnetic resonance imaging (MRI)-based prostate volume to estimate the number of seeds needed for appropriate dose coverage in permanent brachytherapy for prostate cancer. Materials and Methods: Between March 2007 and March 2011, among 112 patients who underwent permanent brachytherapy with $^{125}I$, 60 image scans of 56 patients who underwent preplan CT (pCT) or preplan MRI (pMRI) within 2 months before brachytherapy were retrospectively reviewed. Twenty-four cases among 30 cases with pCT and 26 cases among 30 cases with pMRI received neoadjuvant hormone therapy (NHT). In 34 cases, NHT started after acquisition of preplan image. The median duration of NHT after preplan image acquisition was 17 and 21 days for cases with pCT and pMRI, respectively. The prostate volume calculated by different modalities was compared. And retrospective planning with iTRUS image was performed to estimate the number of $^{125}I$ seed required to obtain recommended dose distribution according to prostate volume. Results: The mean difference in prostate volume was 9.05 mL between the pCT and iTRUS and 6.84 mL between the pMRI and iTRUS. The prostate volume was roughly overestimated by 1.36 times with pCT and by 1.33 times with pMRI. For 34 cases which received NHT after image acquisition, the prostate volume was roughly overestimated by 1.45 times with pCT and by 1.37 times with pMRI. A statistically significant difference was found between preplan image-based volume and iTRUS-based volume (p<0.001). The median number of wasted seeds is approximately 13, when the pCT or pMRI volume was accepted without modification to assess the required number of seeds for brachytherapy. Conclusion: pCT-based volume and pMRI-based volume tended to overestimate prostate volume in comparison to iTRUS-based volume. To reduce wasted seeds and cost of the brachytherapy, we should take the volume discrepancy into account when we estimate the number of $^{125}I$ seeds for permanent brachytherapy.

• Journal of Cadastre & Land InformatiX
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• v.48 no.1
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• pp.71-91
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• 2018

In recent years, application of UAV(Unmanned Aerial Vehicle) to seed sowing and pest control has been actively carried out in the field of agriculture. In this study, UAS(Unmanned Aerial System) is constructed by combining image sensor of various wavelength band and SfM((Structure from Motion) based image analysis technique in UAV. Utilization of UAS based vegetation survey was investigated and the applicability of precision farming was examined. For this purposes, a UAS consisting of a combination of a VIS_RGB(Visible Red, Green, and Blue) image sensor, a modified BG_NIR(Blue Green_Near Infrared Red) image sensor, and a TIR(Thermal Infrared Red) sensor with a wide bandwidth of $7.5{\mu}m$ to $13.5{\mu}m$ was constructed for a low cost UAV. In addition, a total of ten vegetation indices were selected to investigate the chlorophyll, nitrogen and water contents of plants with visible, near infrared, and infrared wavelength's image sensors. The images of each wavelength band for the test area were analyzed and the correlation between the distribution of vegetation index and the vegetation index were compared with status of the previously surveyed vegetation and ground cover. The ability to perform vegetation state detection using images obtained by mounting multiple image sensors on low cost UAV was investigated. As the utility of UAS equipped with VIS_RGB, BG_NIR and TIR image sensors on the low cost UAV has proven to be more economical and efficient than previous vegetation survey methods that depend on satellites and aerial images, is expected to be used in areas such as precision agriculture, water and forest research.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.247-252
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• 2006

For the spring ephemeral and myrmecochorous perennia, Corydalis filistipes Nakai (Fumariaceae), rare and narrow endemic to Ullung Island in Korea, genetic diversity and structure of 4 subpopulations of the species were investigated with allozyme markers. Levels of genetic diversity (A=1.73, $P_{95%}$=61..2%, Ho=0.201, He=0.167) were relatively lower than those of other endemic species with widespread distribution range, but considerably higher than other endemic species with similar life history traits isolated in island. The moderate level of genetic diversity within subpopulations in C. filistipes is characteristic of the species with predominantly outcrossing, myrmecochorous seed dispersal by dual function of the elaisome and mode of sexual and asexual reproduction by the cleistogamy. The analysis of fixation indices showed an overall excess of heterozygotes (mean $F_{IS}=-0.1889,\;F_{IT}=-0.1226$) relative to H-W expectations. About 5.6% of the total genetic variation was found among subpopulations ($F_{ST}$=0.0557). The strategies of reasonable conservation and management, and the maintenance mechanism of genetic diversity of Corydalis filistipes Nakai, endemic plant species in Korea were discussed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.1084-1089
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• 2008

This study was carried to investigate the proximate compositions, capsacinoids, organic acid of various red pepper (Capscium annuum L.) seeds. Twenty domestic varieties of red pepper seeds cultivated in Korea and four foreign varieties of samples cultivated in New Mexico, USA were analyzed. In proximate composition of the various red pepper seeds, ash content showed a range of $3.11{\pm}0.03{\sim}3.77{\pm}0.01%$, and protein content showed a range of $13.25{\pm}0.01{\sim}16.53{\pm}0.08%$. On the other hand, crude lipid content showed wide range distribution of $18{\sim}30%$ and total dietary fiber showed a range of $40{\sim}65%$. Capsaicin content of various red pepper seeds showed $0.09{\pm}0.04{\sim}5.32{\pm}0.14\;mg%$ and dihydrocapsaicin was $0.00{\sim}2.17{\pm}0.18\;mg%$. Capsaicin content was higher than dihydrocapsaicin content. In the organic acid content, Dangchan, Chohyang and Mixed red pepper seed showed a low range of $1.6{\sim}1.9%$; in contrast, Chunhamujuk, Samgang, Ganggun, Wangdaebak, Chunhailpum, New Mexico 6 and LB-25 showed higher values of over 5%.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.44.3-45
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• 2017

To date, luminous quasars at z ~ 6 have been found to be in maximal accretion with the Eddington ratios, ${\lambda}Edd$ ~ 1, suggesting enhanced nuclear activities in the early universe. However, this may not be the whole picture of supermassive black hole (SMBH) growth since previous studies have not reached on faint quasars that are more likely to harbor SMBHs with low ${\lambda}Edd$. To understand the accretion activities in quasars at high redshift, we obtained the deep near-infrared (NIR) spectrum of a quasar, IMS J2204+0112, one of the few faintest quasars that have been identified at z ~ 6. From the NIR spectrum, we find that IMS J2204+0112 harbors a SMBH with about a billion solar mass, with ${\log}({\lambda}Edd)=-0.91$. This is the lowest accretion rate found so far for quasars at z ~ 6, but a common value among quasars at z ~ 2. The inclusion of this object in the ${\lambda}Edd$ analysis gives the intrinsic ${\lambda}Edd$ distribution of z ~ 6 quasars, which is lower than previous results that are based on bright quasars, but it is still higher than ${\lambda}Edd$ of z ~ 2 quasars. Although the number statistics needs to be improved in future, the low peak ${\lambda}Edd$ value is consistent with the SMBH growth from a massive black hole seed (~ 105 Msun) or from a stellar mass black hole through short-duration super-Eddington accretion events (${\lambda}Edd$ > 10).

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.658-675
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• 2016

The environmental characteristics of the habitats, the population structures, ecological niche, life traits and the population demography are used as an essential informations to the effective conservation plans about the target species. We first confirmed a total of 37 populations through 12 years of investigation on the extents, and investigated the environmental factors of habitats and the population structures of the 25 cohorts in 12 regions among them. And, we investigated the population dynamics targeting at 8 cohorts in the population of Daegwanryeong-myeon, Pyeongchang-gun, Gangwon-do. Along with this, we conducted 4 years of cultivation experiments and how pollinators affect the success of reproduction. The results shows that the Paeonia obovata Maxim. was found in a relatively wide range of habitats. For the population structures of the 25 cohorts, there were considerable differences among cohorts, including a case which showed relative stable structure and an extreme case in which only adults were found. The factor that affected the population dynamics during the investigation was thought as a forest gap created in the tree layer. In the cultivation experiment, seedlings grew well in a less soil organic matter. The seed setting rate and the number of seeds generated by visiting pollinators were higher trends. In conclusion, to understand the distribution of the Paeonia obovata Maxim., there needs to be investigated on the other factors that are involved in dispersal factors other than environmental factors, and thus we suggest the necessity of the research on the dispersal vectors. The current Paeonia obovata Maxim. population was thought as a process of expansion after the rapid reduction of the extents in the past. For the effective conservation of the Paeonia obovata Maxim., an endangered plant, we recommend to understand the species through the spatio-temporal expansion, and maintain the health of the ecosystem based on it.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.107-114
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• 2007

Establishments of the seedlings inside the natural forest from adjacent artificial forests would be an important factor in forest stand dynamics. This study was conducted to see the invasion of Korean pine (Pinus koraiensis) seedlings which is not native in this region, into the natural deciduous broad-leaved forest in Gwangneung, Korea. There is no mother tree at the I ha study site while the number of naturally regenerated P. koraiensis seedlings was 345 trees and 56% of them were clumped with more than two seedlings at each point. Applying the image segmentation method to IKONOS satellite image of January, 2003, the distance from the center of 1 ha study site to the nearest mother tree and plantation of Korean pine were 200 m and 270 m, respectively. The average height and root-collar diameter of the seedlings were 34 em and 7 mm, respectively and the age of 207 seedlings (60%) were below 5 years old. Most abundant range of soil moisture gradient and LAl (leaf area index) were from 16 to 20% and those of LAI were from 3.1 to 3.5. To understand the dynamics and seed dispersal pattern of Korean pine in the Gwangneung natural deciduous broad-leaved forests, additional studies not only long-term monitoring of growth and mortality of naturally regenerated Korean pine seedlings but also application of stable isotope analysis and molecular genetic techniques was recommended.