• Journal of the Korea Computer Graphics Society
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• v.23 no.1
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• pp.49-55
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• 2017

Computed tomographic angiography (CTA) is widely used in the diagnosis and treatment of coronary artery disease because it shows not only the whole anatomical structure of the cardiovascular three-dimensionally but also provides information on the lesion and type of plaque. However, due to the large size of the image, there is a limitation in manually extracting coronary arteries, and related researches are performed to automatically extract coronary arteries accurately. As the coronary artery originate from the ascending aorta, the ascending aorta and ostium should be detected to extract the coronary tree accurately. In this paper, we propose an automatic segmentation for the ostium as a starting structure of coronary artery in CTA. First, the region of the ascending aorta is initially detected by using Hough circle transform based on the relative position and size of the ascending aorta. Second, the volume of interest is defined to reduce the search range based on the initial area. Third, the refined ascending aorta is segmented by using a two-dimensional geodesic active contour. Finally, the two ostia are detected within the region of the refined ascending aorta. For the evaluation of our method, we measured the Euclidean distance between the result and the ground truths annotated manually by medical experts in 20 CTA images. The experimental results showed that the ostia were accurately detected.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.638-647
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• 2010

The genetic relationships in 5 species of $Ligularia$ were investigated using RAPD (Randomly Amplified Polymorphic DNA) and ITS (Internal Transcribed Spacer) sequences analyses. In RAPD analysis, sixty three of 196 arbitrary primers showed polymorphism. The amplified fragments ranged from 0.2 to 1.6 kb in size. The dendrogram was constructed by the UPGMA clustering algorithm based on genetic similarity of RAPD markers. A total of 16 accessions were classified into 5 major groups corresponding each species at the similarity coefficient value of 0.77. In the ITS sequence analysis, the size of ITS 1 was varied from 248 to 256 bp, while ITS 2 was varied from 220 to 222 bp. The 5.8S coding region was 164 bp in lengths. Forty nine sites (10.2%) of the 478 nucleotides were variable, and the G+C content of ITS region ranged from 49.4 to 53.5%. In the ITS tree, five species of $Ligularia$ were monophyletic, and $L.$ $taquetii$ was the first branching within the clade. $Ligularia$ $intermedia$ formed a clade with $L.$ $fischeri$ var. $spiciformis$ (BS=79), and $L.$ $stenocephala$ and $L.$ $fischeri$ were also claded. Two data sets were congruent, except of the position of $L.$ $fischeri$ var. $spiciformis$.

• Journal of Pharmaceutical Investigation
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• v.27 no.4
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• pp.303-311
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• 1997

Proliposomal patch of clenbuterol, ${\beta}_2-agonist$ bronchodilator, was prepared and its feasibility as a novel transdermal drug delivery system was examined. Proliposomal granules containing clenbuterol was prepared by a standard method using sorbitol and lecithin with (Rx 2) or without cholesterol (Rx 1). The porous structure of sorbitol in the proliposomes was maintained allowing tree flowability of the granules. Following contact with water, the granules were converted probably to liposomes almost completely within several minutes. It indicates that proliposomes may be hydrated, when they are applied on the skin under occlusive condition in vivo, by the sweat to form liposomes. Clenbuterol release from Rx 1 and Rx 2 proliposomes to pH 7.4 isotonic phospate buffer (PBS) across cellulose membrane (mol. wt. cut-off of 12000-14000) was retarded significantly compared with that from the mixture of clenbuterol powder and blank proliposomes. Interestingly, proliposomes prepared with lecithin and cholesterol (i.e., Rx 2 proliposomes) showed much more retarded release of clenbuterol than proliposomes prepared only with lecithin (i.e.. Rx 1 proliposomes), indicating that clenbuterol release from proliposomes can be controlled by the addition of cholesterol to the proliposomes. Proliposomal patches were prepared using PVC film as an occlusive backing sheet, two sides adhesive tape (urethane, 1.45 mm thickness) as a reservoir for proliposome granules and Millipore MF-membrane (0.45 mm pore size) as a drug release-controlling membrane. Rx 1 or Rx 2 proliposomes containing 4.6 mg of clenbuterol were loaded into the reservoir of the patch. Clenbuterol release from the patches to pH 7.4 PBS was determined using USP paddle (50 rpm)-over-disc release method. Clenbuterol release from the proliposomal patches was much more retarded even than from a matrix type clenbuterol patch (Boehringer Ingelheim ltd). Being consistent with clenbuterol release from the proliposomal granules, the release from the patches was highly dependent on the presence of cholesterol in the proliposomes : Patches containing Rx 2 proliposomes showed several fold slower drug release than patches containing Rx 1 proliposomes. When the patch containing Rx 1 proliposomes was applied on to the back of a hair-removed rat, clenbuterol concentration in the rat blood was maintained during 6-72 hrs. Transdermal absorption of clenbuterol from the patch was accelerated when the patch was prehydrated with 50 ml of pH 7.4 PBS before topical application. Above results indicate that sustained transdermal delivery of clenbuterol is feasible using proliposomal patches if the cholesterol content and pore size of the release rate-controlling membrane of patches, for example, are appropriately controlled.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.235-243
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• 2002

Ni-base superalloys are used extensively in industry, both in aeroengines and land based turbines. About 60% by weight of most modern gas turbine engine structural components are made of Ni-base superalloys. To satisfy practical demands, the efficiency of gas turbine engines has been steadily and systematically increased by design modifications to handle higher turbine inlet or firing temperatures. However, the increase in operating temperatures has lead to a decrease in the life of components and increase in costs of replacement. Moreover, around 80% of the large frame size industrial/utility gas turbines operating in the world today were installed in the mid-sixties to early seventies and are now 25 to 30 years old. Consequently, there are greater opportunities now to repair and refurbish the older models. Basically, there are two major factors influencing the weldability of the cast alloys: strain-age cracking and liquation cracking. Susceptibility to strain-age cracking is due to the total Ti plus AI content of the alloy; Liquation cracking is due either to the presence of low melting constituents or constitutional liquation of constituents. Though Rene 41 superalloy has 4.5wt.% total Ti and Al content and falls just below the safe limit proposed by Prager et al., controlled grain size and special heat treatments are needed to obtain crack-free welds. Varying heat treatments and filler materials were used in a laboratory study, then the actual welding of service parts was carried out to verity the possibility of crack-tree weld of components fabricated from Rene 41 superalloy. The microstructural observations indicated that there were two kinds of carbides in the FCC matrix. MC carbides were located along the grain boundaries, while M$_{23}$C$_{6}$ carbide was located both inter and intra granularly. Two kinds of filler materials, Rene 41 and Hastelloy X were used to gas tungsten arc weld a patch into the sheet metal, along with varying pre-weld heat treatments. The microstructure, hardness and tensile tests were determined. The service distressed parts were categorized into three classes: with large cracks, with medium cracks and with small or no visible cracks. No significant difference in microstructure among the specimens was observed. Specimens were cut from the corner and the straight edge of the patch repair, away from the corner. The only cracks present were found to be associated with inadequate surface preparation to remove oxidation. Guidelines for oxide removal and the welding procedures developed in the research enabled crack-free welds to be produced.d.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.219-225
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• 2006

To study song themes and variation of Yellow-throated Bunting, we obtained and analyzed recordings from 45 males breeding in 16 deciduous forests of 6 provinces. We classified the 3,245 songs into a total of 164 song themes and 1,024 song variants according to the identification on the base of difference(lexicon) in 640 syllable compositions. Males had one to six song themes and averaged 3.5 themes. No males shared an identical song theme. Males had $5{\sim}14$ syllables (ave. 9.4) in one song theme and males increased effectively their repertoire size by changing syllable composition (i.e. adding, deleting, or substituting one or more syllables) in a single song theme. The number of variants averaged 5.1 (range 1 to 31) per song theme. Individual variability was highest in the terminal elements of the song. In PCA, the 16 populations are clearly separated on Co. I based on shared syllable and on Co. II based on unique syllable. Similarity of songs based on shared syllables by distance coefficients, showed a pattern of concordance with geography. Pairwise similarity declined with increasing distance among recording sites. 16 different geographical regions by the syllable were divided in UPGMA tree.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.4
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• pp.83-97
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• 2013

The traditional village forests in Korea such as Dangsan forests and Bibo forests form unique cultural landscape and they are national cultural assets with histories of more than several hundred years. It is important to have sustainable right to enjoy cultural heritage as well as maintaining its authenticity. Cultural assets are meaningful only when they are managed to succeed to next generations. Dangsan forests and Bibo forests need to be named properly and recognized by society as a precious cultural heritage for many generations to come in order to claim the value as traditional cultural landscapes in Korea. The traditional village forest in Dangin-ri, Wando-gun was composed of a Dangsan forest and five Bibo forests. Although this traditional village forest is large in size, it was not on the report of Cultural Heritage Administration(2005) investigated for 'Village forest of island region in Jeollanam-do'. The objective of this study was to investigate the characteristics of the traditional village forest in Dangin-ri to grant correct name and to enhance its value. In this study the characteristics of a Dangsan forest and five Bibo forests were investigated from 2006 to 2013 for physical features such as size, shape, location, tree species composition, and diameter at breast height(DBH), as well as cultural aspects and tradition. Currently the naming and designation of natural monuments by the cultural heritage administration(CHA) is based on the rule enacted in 1934. Many Dangsan forests were named as evergreen forests. This type of names does not represent the meaning of traditional village forest. It was suggested that this traditional village forest is to be named as 'Dangsan Forest and Bibo Forests at Dangin-ri, Wando-gun'. This traditional village forest needs to reclaim authenticity and rebuild its original appearance by restoration of the disturbed areas, especially in Bibo forest I.

• Journal of the Korean association of regional geographers
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• v.2 no.2
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• pp.197-204
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• 1996

We attempt to classifing method of micro-landform on the alluvial plain, such as natural-levee, backmarsh and alluvial fan, using false color composite of Landsat Thematic Mapper image. The study area is Kumho River Basin on the southeastern part of Korea peninsula. The most effective image for micro-landform classification is the false color composite of band 2, 3 and 4 with blue, green and red filtering. The most favorable time is the middle third of November, because of the density differentiation of green vegetation in most great. In this time the paddy field on the back-marsh is bare by rice harvesting. But on the natural levee the green vegetation, such as vegetables and lower herbs under fruit tree, remain relatively more. On the alluvial fan, the green vegetation condition is medium. For the verification of the micro-landform classification, we employed the field survey and grain size analysis of the deposition of each micro-landform on the sample area. It is clarified that the classification method of micro-landform on the alluvial plain using the Landsat TM image is relatively useful.

• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.580-597
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• 2015

Broadcast encryption system is a cryptographic primitive that enables a sender to broadcast a message to a set of receivers in a secure channel. Out of previous proposed broadcast encryption systems, the most effective is the one that uses the Subset Difference(SD) method in a binary tree structure. The SD method has been realized by two underlying approaches: Pseudo-Random Generator(PRG) and Secret Sharing(SS). 2-SD method is the generalized version of the SD method by which two subsets of revoked receivers can be dealt with by one subset (in an SD-based broadcast encryption system). The primary advantage of the 2-SD method is to further reduce the size of transmission overhead, compared to the SD method. Until now, however, there is no known broadcast encryption system that is based on such a 2-SD technique using either PRG or SS basis. In this paper, we suggest a new 2-SD broadcast encryption system using the SS-based technique that was suggested by Jae Hwan Lee et al. in 2014[9]. The new system can reduce the size of ciphertext by 25% of the one in the previous SS-based broadcast encryption system. Also, on a theoretical note, ours is the first 2-SD broadcast encryption system that is provably secure.

• The Korean Journal of Zoology
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• v.8 no.2
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• pp.89-127
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• 1965

1. This report is on the outcome of observation made up the breeding process of Narcissus flycatcher, Muscicapa narcissina zanthopygia, using 15 ness-boxes at Seoul and Kwang Nung Experimental forest in 1964, and the relevant feeding habit was studied by the collar method of wrapping the necks of thenestlings for 50-60 minutes or more in some cases from 1963 to 1964. 2. The Narcissus flycatcheris a common summer resident throughout Korea arriving at the end of April. The earliest data of arrival of this species in Seoul, is April 26, 1964. They migrate southward from the later part of September to early part of October. 3. In a week after their arrival , they start to build nest after a brief courtship. Male and female prepare their nest ina nestboxes in 4 or 5 days. Nests are usually found in the moss, which provide definite frame-work. The inner side of the nest is usually composed of roots of Gramineae or leaves of pine, oak or other broad leave tree. 4. The laying period is generally from the later part of April to the middle of June : and the number of eggs laid is from 3 to 8 , therefore 5 in average : eggs are pink with traces of milky yellow blending of light auburn and orange red spots and chicken-egg-like in shape. 5.The incubation takes place for 7-12 days from the middle part of May to the middle of June, in the order of male and female . The hatching rate tends to increase in proportion to clutch size. 6. The feeding period usually lasts 15 days in average from the early part of June to the middle of July and the feeding urge tends to increase in proportion to brood size. 7. The animals invading into their nest-boxes are red ants, chipmunks, bees , barkbeetles and philippine red-tailed shirkes, etc. 8. On the basis of analysis covering 714 birds in 31 nests, the food they consumed during the nesting period of nestlings were mostly of animal matters composing of : insect larvae form-39. 88% insect adult form 36.26%, insect pupae-0.19%, spider-17.75% and other animal matters 5.92% , Besides a small amount of plant pieces were found . As to the insect larvae, Lepidoptera was the largest in the content followed by Hymenoptera , Orthoptera and Coleoptera. As to the insect adult, Diptera was the largest in the content followed by Coleoptera, and Hymenoptera. In view of forest protection, noxious insect was of 69.38%, useful insect 4.39%, and spider 17.75%. 9. The rich assortment of its food, the ability of acquiring various insect (adults as well as larvae), its destruction of great numbers of harmful insects , and its quick assimilation artificial nesting with the nest-boxes of 2.5-3cm entrance hole employed, allow us to conclude that the flycatcher may be successfully employed in the elimination of fores pests. The above results are only that part obtained near Seoul in the middle of Korea, however, if we would extend the scheme to other broad areas using similar techniques, the nest-boxes could not only be well used by the birds, but also it would help to prevent the increase of harmful. insects.

• Korean Journal of Plant Taxonomy
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• v.40 no.4
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• pp.274-277
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• 2010

This study was performed to report the augmented wild populations of Forsythia koreana (Rehder) Nakai and Abeliophyllum distichum Nakai in Korea. Forsythia koreana was found in Budong-myeon, Cheongsong-gun, Gyeongsangbuk-do. The overall size of the natural habitat of Forsythia koreana is $5m{\times}5m$. A total of 12 individuals were recorded in the wild, and 3 of them were in the seedling stage. The wild habitat is in a secondary forest, which is co-dominated by Pinus densiflora Siebold & Zucc and Robinia pseudoacacia L, with 15% coverage. The coverage of the shrub layer is 40% and is dominated by Spiraea prunifolia for. simpliciflora Nakai. The natural habitat of Abeliophyllum disitichum, which is recorded in Uisong-up, Gyeongsangbuk-do, is distributed in sites characterized by boulders along streams, with a patchwork of 15 scattered areas over a habitat size of $50m{\times}15m$. Quercus variabilis Blume is a dominant species in this habitat, with this species dominating at the sub-tree layer. Celtis aurantiaca Nakai also dominates at the shrub layer. The natural ranges of these two species in Korea were mapped based on the terms of the extent of occupancy (EoO).