• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.10a
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• pp.78.2-78
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• 1999

• Journal of Information Processing Systems
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• v.12 no.3
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• pp.422-435
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• 2016

Despite the convenience brought by the advances in web and Internet technology, users are increasingly being exposed to the danger of various types of cyber attacks. In particular, recent studies have shown that today's cyber attacks usually occur on the web via malware distribution and the stealing of personal information. A drive-by download is a kind of web-based attack for malware distribution. Researchers have proposed various methods for detecting a drive-by download attack effectively. However, existing methods have limitations against recent evasion techniques, including JavaScript obfuscation, hiding, and dynamic code evaluation. In this paper, we propose an emulation-based malicious webpage detection method. Based on our study on the limitations of the existing methods and the state-of-the-art evasion techniques, we will introduce four features that can detect malware distribution networks and we applied them to the proposed method. Our performance evaluation using a URL scan engine provided by VirusTotal shows that the proposed method detects malicious webpages more precisely than existing solutions.

• Korean Journal of Veterinary Service
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• v.36 no.3
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• pp.151-155
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• 2013

Since a large number of Akabane and bovine ephemeral fever (BEF) infection occurred in the southern part of Korea in 2010, recent information about seroprevalence of Akabane virus (AKAV) and bovine ephemeral fever virus (BEFV) has been required for preventing both diseases. In this study, serological assay against AKAV and BEFV using virus neutralization assay was conducted using 1,743 bovine sera collected from Namwon, Miryang, Yeongju and Uljin which located in Southern part of Korea from March to May in 2012. The overall seropositive rates for AKAV and BEFV were found to be 49.8% and 1.2%, respectively. The regional distribution of seroprevalence for AKAV ranged from 18.1% to 63.7%. Seroprevalences of AKAV were 63.7% in Miryang, 62.3% in Uljin, 50.7% in Namwon, and 18.1% in Yeongju. The seropositive rates for AKAV in southern part of Korea were higher than the annual average at the national level. On the other hand, seropositive rates of BEFV in four regions were from 0.3 to 3.1%. In detail, regional seroprevalences were 3.1% in Miryang, 2.0% in Uljin, and 1.7% in Yeongju, and 0.3% in Namwon. Even only one year after massive outbreaks, overall seropositive rates were very low, similar to the annual average at the nation level. This result indicates that many number of cattle infected with BEFV may be replaced by new born calf or cattle in farm may not be immunized with vaccines. To prevent another epidemic, a national wide warning should be issued and more aggressive control measure must be implied. Recent global warming phenomenon could lead to more vigorous activity of haematophagous vectors and it is possible that arboviral diseases such as AKAV and BEFV are increased. Therefore, continuous sero-monitoring and extensive vaccination combined with control of haematophagous vectors are important to effectively prevent and control diseases caused by AKAV and BEFV.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.592-596
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• 2014

HMO-2011, a recently isolated lytic phage that infects the SAR116 bacterial clade, represents one of the most abundant phage types in the oceans. In this study, the HMO-2011 genome sequence was compared with virome sequences obtained from various depths of the Pacific Ocean regions using metagenome binning. HMO-2011 was confirmed to be one of the most highly assigned viruses, with a maximum of 7.6% of total reads assigned. The HMO-2011-type phages demonstrated a depth-specific distribution, showing more abundance in the euphotic zone of coastal, transition, and open ocean regions as compared with the dark ocean.

• Journal of Life Science
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• v.19 no.10
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• pp.1451-1455
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• 2009

Porcine cytomegalovirus (PCMV) is a betaherpesvirus which causes reproductive failure in breeding sows and generalized infection in newborn piglets. It has worldwide distribution including Korea. Serological survey on this virus has been reported in 76.3% of pigs, but virological survey and epidemiological analysis on PCMV distribution have been reported in only a few papers in Korea. In this study, we investigated the virological prevalence and infection status of PCMV on a farm level in selected swine farms with respiratory diseases. A total of 1,938 blood samples taken from groups of pigs of different ages were collected from 31 farms distributed nationwide in 2006 and 2007 and tested by PCR to detect the presence of PCMV. Virological prevalence at farm level and pig level were 96.8% and 17.5%, respectively, suggesting that PCMV has endemically infected Korean pig herds. The prevalence at farm level in gilts, sows and suckling piglet groups were 16.7%, 36.7% and 56.7%, indicating that vertical infections frequently occurred in conception or newborn stage. Thereafter, detection rates of PCMV were slightly increased in pig groups aged 40 and 70 days (70.0% and 73.3%), and then gradually decreased as they aged - 33.3% in 100, 26.7% in 130 and 16.7% in 160 day old pig groups. The prevalence at pig level has similar patterns to that at farm level. With the passage of time, the variation of infection patterns of PCMV was investigated in four PCMV-positive farms. Three blood samples were collected at intervals of 6 months in each farm, and examined for presence of PCMV using PCR. The results revealed that once PCMV was introduced to the pig farms, it continuously circulated between and within groups of sows and piglets in those farms. Taken together, it can be concluded that PCMV has endemically infected Korean pig farms and has the potential risk for emerging pathogen in combination with the known endemic pathogens including porcine reproductive, respiratory syndrome virus and porcine circovirus type 2. Therefore, more research is needed on diagnosis, epidemiology and control strategy for PCMV on the field.

• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.75-80
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• 2016

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging disease characterized by fever and thrombocytopenia. Haemaphysalis longicornis ticks comprise the major population of ticks in the environment and have been considered as the main vector for SFTS virus (SFTSV). Here we investigated the distribution of ticks carrying SFTSV collected from the environment using the dragging or sweeping methods during April~October 2015 in Jeollanam-do, Korea. Sampling was taken from Songjeong, Omi, Bangkwang, Sandong areas in Jiri walking trails. Among the total 3,869 ticks collected, 3,823 ticks (98.8%) were H. longicornis, 41 (1.1%) were Amblyomma testudinarium, and 5 (0.1%) were Ixodes nipponensis. Classification results by regional groups of H. longicornis indicated that 1,613 ticks were collected in Sandong, 1,190 ticks in Omi, 603 ticks in Bangkwang, and 417 ticks in Songjeong. In monthly distributional studies of H. longicornis based on the developmental stages, nymph (325 ticks) was collected from May to October, 94% of larvae from April to June, and 94% of adult from June to August. These results showed the different dominant stage of ticks according to seasons. However, no SFTSV-specific gene was detected in 3,823 ticks of H. longicornis, 41 of A. testudinarium and 5 of I. nipponensis.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.324-329
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• 2009

Purpose : Acute interstitial pneumonia (AIP) is a rare disease, but its prognosis is fatal because of lack of efficient treatment modality. Recently, it has been reported that there was epidemic AIP in Korea. This study aims to investigate the past and current status of AIP in Korea. Methods : We performed a nationwide survey and a prospective study. From August 6 to 15, 2008, a questionnaire survey was conducted to identify the prevalence, local distribution, and response to current treatments. The questionnaire was answered by pediatrician working in 23 referral centers in Korea. In addition, 5 referral centers in Seoul performed a preliminary prospective observational study by obtaining clinical data and specimens from appropriate patients. The Korea Centers for Disease Control and Prevention analyzed the samples for possible pathogens. Results : The survey showed 78 AIP cases had occurred and 36 patients had died. Lung biopsy was performed only on 20 patients. In 2008, 9 AIP cases developed. In a prospective study, 9 (M:F=5:4) patients developed AIP in spring and 7 (78%) died, with the mean rate of death occurring 46 days after diagnosis. Human corona virus 229E, cytomegalovirus, influenza A virus, influenza B virus, and parainfluenza virus were isolated from the respiratory specimens. Conclusion : This study showed nationwide prevalence of AIP in Korea. In addition, because of the high mortality rate and rapid progress, pediatricians need to be aware of the disease. Further studies and a nationwide network are required for reducing the morbidity and mortality rates related to AIP.

• The Korean Journal of Cytopathology
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• v.1 no.1
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• pp.74-84
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• 1990

Herpes simplex virus type 1 and 2(HSV-1, HSV-2) are the ubiquitous human pathogens responsible for a variety of afflictions. HSV-2 is one of the viruses that were suspected of promoting carcinogenesis in the uterine cervix. Certainly, there is a need for the more sensitive and accurate laboratory techniques for HSV detection. We examined total 80 cases of smears including 17 Tzanck smears of skin and 63 cases of Papanicolaou smears from total 77 patients with clinical impression of herpetic infections, from September, 1985 through August, 1989. Immunohistochemical typings for HSV-1 and HSV-2 were performed together with routine cytologic findings and compared. The results are as follows : 1) Patients were 9 males and 33 females, and age distribution was between 5 and 71 years. 2) Subjective symptoms such as ulceration, vesicle, vaginal discharge, pruritus, and pain were complained in 36 patients and 38 cases were genital herpes. Recurrence was noted in 11 cases. 3) Positive results were obtained in 42 among 80 cases. 4) Both routine cytology and immunohistochemical staining were positive in 13 cases and in 24 cases only immunohistochemical staining were positive. 5 cases were positive only in routine cytologic smears. 5) The cases that immunocytochemical stain had been performed were 37 cases, which were all positive in type 2. Among the above 37 cases, type 1 also were positive in 5 cases. The results show that the immunoperoxidase technique is one of the rapid and reliable method to confirm the herpetic infection when suspected and that it is particularly useful when the Papanicolaou smear findings are equivocal.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.115-121
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• 1989

A survey on the prevalence and distribution of antibodies to BLV was performed by the agar-gel immunodiffusion test over a period from 1983 to 1985. More than 2,407 serum samples were collected from Holstein cattle raised in the eastern part of Saitama prefecture where suburban dairy farm is operated. The average positive rate of this period was 4.9%. The rates of reactive samples varied from 2.6 to 9.8% among the age groups of cattle from younger than one year to 14 years of age. The positive rate increased gradually with age. The positive rates also varied widely from 0 to 21% among areas surveyed. Furthermore, there were large differences in this rate among farms even in the same area. The results were interpreted and discussed in connection with the enzootic feature of BLV infection.

• Korean Journal of Veterinary Service
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• v.32 no.4
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• pp.315-323
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• 2009

Foot-and-mouth disease (FMD) virus exists in seven serotypes and is known to be a highly contagious disease that is hard to eradicate from the world. The O, A, Asia1 and SAT2 serotypes commonly infected cattle, sheep and goats during 2007~2009 throughout the world. In particular, the outbreak of the Asia1 serotype in China appeared in all areas from 2005 and is still present. Surprisingly, in 2009, Taiwan reported the first outbreak of the type O serotype since 2001. Then type A appeared in China for the first time since the early 1960s. The virus shows a close relationship to the viruses from Southeast Asia suggesting one or more recent introductions into China in the OIE reports. Recently the subtype of A/Iran05 spread to nearby countries exhibiting genomic evolution. The use of molecular epidemiology is an important tool in understanding and consequently controlling the FMD virus. The phylogenetic analysis with VP1 gene was especially useful for molecular epidemiological studies and showed the same pattern which matches with serotype classification. This paper describes basic information about the disease, and the serotype-specific characteristics and evolution to perform molecular epidemiological analysis. Furthermore, we show the importance of the genetic evolution on the FMD serotypes in global surveillance and molecular epidemiology of FMD for outbreak investigation.