• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.212-218
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• 2012

An Internet worm is a self-replicating malware program which uses a computer network. As the network connectivity among computers increases, Internet worms have become widespread and are still big threats. There are many approaches to model the propagation of Internet worms such as Code Red, Nimda, and Slammer to get the insight of their behaviors and to devise possible defense methods to suppress worms' propagation activities. The influence of the network characteristics on the worm propagation has usually been modeled by medical epidemic model, named SI model, due to its simplicity and the similarity of propagation patterns. So far, SI model is still dominant and new variations of the SI model, called SI-style models, are being proposed for the modeling of new Internet worms. In this paper, we elaborate the problems of SI-style models and then propose a new accurate stochastic model using an occupancy problem.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.363-367
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• 1986

Distributional patterns of Ulnung-do's Polychaetous annelid worms comprising 64 species out of 53 genera were divided into four zoogeographical groups with reference to the distribution of the world's polychaetous annelid worms; cosmopolitan, northern, temperate and tropical types. It was found out that there were 25 species of cosmopolitan type taking up $39\%$, 20 species of northern type, $31\%$, and 19 species of temperate type, $30\%$, but tropical type was not found. When compared with the polychaetous annelid worms of the neighboring coastal areas of the Yellow Sea, the east coast of U.S.S.R., Korea and Japan, those of Ulnung-do island were shown to have highest similarity to those of Yellow Sea follwed by the areas in the order named.

• Parasites, Hosts and Diseases
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• v.37 no.2
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• pp.101-107
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• 1999

Rats were immunized through an initial infection with 1,000 filariform larvae (L3) of Nippostrongylus brasiliensis and after complete expulsion of worms they were challenged with 1,000 L3 of Strongyloides venezuelensis to investigate whether cross-resistance developed against a heterologous parasite. Nippostrongylus brasiliensis immunized rats developed a partial cross-resistance against S.venezuelensis migrating larvae (MSL3) in the lungs and adult worms in the small intestine. The population of MSL3 in the lungs were significantly lower (p<0.05) in immunized rats($22.0{\;}{\pm}{\;}7.4$) compared with controls ($105.0{\;}{\pm}{\;}27.6$). The populations of adult worms, egg output and fecundity were initially decreased but from day 14 post-challenge they did not show any significant difference between immunized and control rats. However, the length of worm in immunized rat was revealed as retardation. Peripheral blood eosinophilia was significantly decreased (P<0.05) on day 7 post-challenge and then gradually increased which peaked on da 42 post-challenge when most of the worms were expelled. these results suggest that peripheral blood eosinophilia is strongly involved in the worm establishment and expulsion mechanisms.

• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.230-235
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• 1985

The metacercariae of an echinostomatid fluke were detected from a freshwater 6sh, Odontobutis obscura interrupta caught from the Seom river system, Wonseong-gun, Kangwon-do, and experimentally infected into rats to obtain the adult worms for the species identification. A total of 32 metacercariae was detected from 10 fishes (27.8%) out of 36 O. obscura interrupta caught from the river. The average size of metacercariae was $153.4{\times}149.0{\;}{\mu}{\textrm{m}}$. Also, it was uniquely specific that thickened membrane was formed around the metacercarial cyst wall. The rats orally infected with those metacercariae were sacrificed 20 days after infection to get the adult worms. The mean length and width of the adult worms were 0.75 cm and 0.13 cm, respectively. The number of collar spines on circumoral disk was 26 to 28, and the end group spines at lateral sides of the oral sucker were 4 on each side. The echinostomatid flukes observed in this study were all identified as Echinostoma hortense according to the morphologies of the cirrus sac, ovary, vitellaria and testes of the adult worms and the shape of eggs. On the other hand, O. obscura interrupta is one of the fresh-water fish that are preferably eaten raw by the rural inhabitants. Although no human case of 5. hortense infection by eating O. obscura interrupta has been experienced yet, the possibility is strongly suggested in this study.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.210-216
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• 2007

The backbone structure of ginsenosides, active ingredients of Panax ginseng, is similar with that of sterol, especially cholesterol. Caenorhabditis elegans (c. elegans) is one of free living nematodes and is well-established animal model for biochemical and genetic studies. C. elegans cannot synthesize de novo cholesterol, although cholesterol is essential requirement for its growth and development. In the present study, we investigated the effects of Korean red ginseng total extract (KRGE), ginseng total saponins (GTS) on life span of C. elegans in cholesterol-deprived and -fed medium. Cholesterol deprivation caused damages on life span of worms throughout F1 to F3 generations. KRGE or GTS supplement to cholesterol-deprived medium restored the life span of worms as much as cholesterol alone-fed medium. In study to identify which ginsenosides are responsible for life span restoring effects of KRGE, we found that ginsenoside Rc supplement not only restored life span of worms grown in cholesterol-deprived medium but also prolonged life span of worms grown in cholesterol-fed medium. These results show a possibility that ginsenosides could be utilized by C. elegans as a sterol substitute and further indicate that ginsenoside Rc is the effective component of Korean red ginseng that prolongs the life span of C. elegans.

• Korean Journal of Veterinary Service
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• v.32 no.1
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• pp.83-85
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• 2009

In a cross-sectional abattoir survey of bovine pulmonary diseases in Mymensingh, during September 2001 to April 2002, subclinical Dictyocaulus viviparous infection was found in mesoendemic level in Bangladeshi adult zebu cattle. The number of mature lung worms varied from $1{\sim}18$ in individual lungs. One to five mature lung worms were most frequent (74.2%) followed by 6 to 10(19.3%) and $11{\sim}18$ (6.5%). Of the total 123 mature worms collected from 31 lungs, there were 50 (40.7%) male and 73 (59.3%) female worms. The female lungworms (mean length 14.41mm) were significantly (P<0.01) larger than the male lungworms (mean length 11.28mm). The number of hydatid cysts varied from $1{\sim}80$ in individual lungs. One to five ($1{\sim}5$) cysts were recorded most commonly (76.0%) followed by $11{\sim}80$ (20.0%) and $6{\sim}10$ (4%). The size (diameter) of the hydatid cysts ranged from $2{\sim}12cm$. Of the total 203 hydatid cysts collected from 31 lungs 45 (22.2%) cysts were fertile and 158 (77.8%) cyst were sterile.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.1
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• pp.57-66
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• 2007

Scanning worms increase network traffic load because they randomly scan network addresses to find hosts that are susceptible to infection. Since propagation speed is faster than human reaction, scanning worms cause severe network congestion. So we need to build an early detection system which can automatically detect and quarantine such attacks. We propose algorithms to detect scanning worms using network traffic characteristics such as variance, variance to mean ratio(VMR) and correlation coefficient. The proposed algorithm have been verified by computer simulation. Compared to existing algorithm, the proposed algorithm not only reduced computational complexity but also improved detection accuracy.

• Fisheries and Aquatic Sciences
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• v.26 no.10
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• pp.583-592
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• 2023

Celebes rainbow (Marosantherina ladigesi) is one of Indonesia's exported ornamental fish commodities, but the exploitation of this fish only relies on wild catches. The rise of unlimited fishing, especially those using poison, has changed the aquatic environment, threatening sustainability and causing fish extinction. This study aimed to evaluate the effectiveness of several types of feed in improving the absolute growth rate (AGR), specific growth rate (SGR), survival rate (SR), feed conversion ratio (FCR), feed efficiency (FE), hematology, and immune response of Celebes rainbow. The fish used in this study were male ornamental Celebes rainbow (M. ladigesi) weighing 1.32 ± 0.21 g/ind, reared in 54 L-aquariums at a stocking density of 30 individuals/aquarium for six weeks. The fish were fed according to the test diet consisting of live Tubifex sp worms, dry Tubifex sp worms, Spirulina platensis, and crumble pellets. The parameters observed were AGR, SGR, SR, FCR, FE, hematology, intestinal histology, liver histology, and a challenge test with the pathogenic bacteria Aeromonas hydrophila. The results showed that fish-fed live Tubifex sp worms had better AGR, SGR, SR, FCR, FE, hematology, and disease resistance compared to all other treatments. These results indicate that live Tubifex sp worms are the best feed for rearing Celebes rainbow.

• Parasites, Hosts and Diseases
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• v.24 no.1
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• pp.42-48
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• 1986

As a series of systematic classification of paramphistomes, in the first step, paramphistomes in the lumen and reticulum were collected on 170 Korean catties (2∼3 years age, male) slaughtered at Jeonju abattoir from July, 1984 to September, 1985 and were classified by means of morphology of the worms. Afterwards, the karyotype of Paramphistomum explanatum (Creplin, 1849) which is the common in Korean cattle was detected by means of modified air-drying method from testis cells of the worm. The following is a brief summary of the leading facts gained through the experiment. 1. Most of the cattle slaughtered at the abattoir were infected with paramphistomes. The 5 species of the worms were detected on 170 Korean cattle and the worm burden per head was from 2 to 784(on the average 170) worms, 120(70.59%) heads out of them involving 2∼100 worms. In 28,900 individuals of paramphistomes obtained on 170 Korean cattle, appearance rates of various worms were as follows : 49.74% in P. explanatum, 48.08% in P. cervi, 0.98% in Orthocoelium orthocoelium, 0.89% in Fischoederius cobboldi and 0.14% in Cotylophoron cotylcphorum. 2. The chromosome number of 620 P. explanatum in the haploid and diploid cells was n=9 and 2n=18, and abundant cells in meiotic division were observed; 1,420 haploid and 38 diploid cells were reliable. Nine pairs of mitotic chromosomes were homologous and the chromosomes were composed of aye medium-sized metacentrics(m), subtelocentrics(st) or submetacentrics(sm) and four smallsized subtelocentrics(st) or submetacentrics(am), while meiotic metaphase chromosomes were composed of five medium and four small-sized. 3. The haploid of the testis cells showed C-band in the centromeric region from 8 of them, whereas the remaining chromosome No. 5 included heterochromatin on the tip region, and chromosomes No. 3 and No. 7 showed a remarkable C-band distinguished from other chromosomes.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.275-281
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• 2014

After harvesting the medicinal parts of Curcuma longa, the remaining underground parts were discarded. From the remaining underground parts of Curcuma longa quercetin-3-O-${\beta}$-D-glucopyranoside-7-O-${\alpha}$-L-rhamnopyranoside (Q37) was isolated. The antioxidant activities in vitro and lifespan-extension effect of Q37 were elucidated using the Caenorhabditis elegans. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect of Q37 showed similar potent activities in comparison with vitamin C. Q37 also showed potent superoxide quenching activities as measured by the riboflavin- and xanthine-originated superoxide quenching activity tests. Q37 prolonged lifespan of worms under normal culture condition. In terms of protective effect of Q37 on the stress conditions such as thermal and oxidative stresses, Q37-treated worms exhibited enhanced survival rate, as compared to control worms. To know the possible mechanism of Q37-mediated increased lifespan and stress resistance of worms, we examined the activities of Q37on superoxide dismutase (SOD), and invested intracellular reactive oxygen species (ROS) levels. The results revealed that Q37 was able to elevate SOD activity of worms and reduce intracellular ROS accumulation in a dose-dependent manner.