• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.6
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• pp.1325-1336
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• 2012

In the past about 10 different kinds of malicious code were found in one day on the average. However, the number of malicious codes that are found has rapidly increased reachingover 55,000 during the last 10 year. A large number of malicious codes, however, are not new kinds of malicious codes but most of them are new variants of the existing malicious codes as same functions are newly added into the existing malicious codes, or the existing malicious codes are modified to evade anti-virus detection. To deal with a lot of malicious codes including new malicious codes and variants of the existing malicious codes, we need to compare the malicious codes in the past and the similarity and classify the new malicious codes and the variants of the existing malicious codes. A former calculation method of the similarity on the existing malicious codes compare external factors of IPs, URLs, API, Strings, etc or source code levels. The former calculation method of the similarity takes time due to the number of malicious codes and comparable factors on the increase, and it leads to employing fuzzy hashing to reduce the amount of calculation. The existing fuzzy hashing, however, has some limitations, and it causes come problems to the former calculation of the similarity. Therefore, this research paper has suggested a new comparison method for malicious codes to improve performance of the calculation of the similarity using fuzzy hashing and also a classification method employing the new comparison method.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.10
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• pp.363-372
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• 2022

Since the recent COVID-19 Pandemic, the ransomware fandom has intensified along with the expansion of remote work. Currently, anti-virus vaccine companies are trying to respond to ransomware, but traditional file signature-based static analysis can be neutralized in the face of diversification, obfuscation, variants, or the emergence of new ransomware. Various studies are being conducted for such ransomware detection, and detection studies using signature-based static analysis and behavior-based dynamic analysis can be seen as the main research type at present. In this paper, the frequency of ".text Section" Opcode and the Native API used in practice was extracted, and the association between feature information selected using K-means Clustering algorithm, Cosine Similarity, and Pearson correlation coefficient was analyzed. In addition, Through experiments to classify and detect worms among other malware types and Cerber-type ransomware, it was verified that the selected feature information was specialized in detecting specific ransomware (Cerber). As a result of combining the finally selected feature information through the above verification and applying it to machine learning and performing hyper parameter optimization, the detection rate was up to 93.3%.

• Journal of Life Science
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• v.32 no.5
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• pp.375-390
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• 2022

Influenza viruses are zoonotic respiratory pathogens, and influenza infections have caused a substantial burden on public health systems and the livestock industry. Although currently approved seasonal influenza vaccines have shown potent protection efficacy against antigenically well-matched strains, there are considerable unmet needs for the efficient control of viral infections. Enormous efforts have been made to develop broadly protective universal influenza vaccines to tackle the huge levels of genetic diversity and variability of influenza viruses. In addition, antiviral drugs have been considered important interventions for the treatment of viral infections. The viral neuraminidase inhibitor oseltamivir is the most widely used antiviral medication to treat influenza A and influenza B viruses. However, unsatisfactory clinical outcomes resulting from side effects and the emergence of resistant variants have led to greater attention being paid to plants as a natural resource for anti-influenza drugs. In particular, the recent COVID-19 pandemic has underpinned the need for safe and effective antiviral drugs with a broad spectrum of antiviral activity to prevent the rapid spread of viruses among humans. This review outlines the results of the antiviral activities of various natural products isolated from plants against influenza viruses. Special focus is paid to the virucidal effects and the immune-enhancing effects of antiviral natural products, since the products have broad applications as inactivating agents for the preparation of inactivated vaccines and vaccine adjuvants.

• Journal of Life Science
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• v.32 no.12
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• pp.956-961
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• 2022

Plant Chloroplast have several advantages as an expression platform of biopharmaceuticals over conventional expression platforms such as mammalian cells, yeast and bacteria. First, plants do not serve as a host for mammalian infectious virus and have endotoxin like bacteria which can cause anaphylactic shock. In addition, high copy number of chloroplast genome allows for chloroplast transformants to reach the high level of expression of heterologous genes. Moreover, the integration of transgenes into specific region of chloroplast genomes makes chloroplast transformants unaffected by positional effect which can be frequently observed from nuclear transformants, resulting in loss of transgene expressions. Antimicrobial peptides (AMPs) are a kind of innate immunity which is found from bacteria to humans. Unlike conventional antibiotics, very less dosage of AMPs can have catastrophic effect on bacterial survival. Further, the repeated use of AMPs does not trigger the development of bacterial resistance. Moricin, one of the AMPs, was isolated from Bombyx mori, a silkworm moth. The C-terminal of moricin consists largely of basic amino acids, and the N-terminal has an α-helix structure. Moricin was chosen and expressed in a SUMO/SUMOase without leaving any unwanted amino acids which could potentially affect the anti-bacterial activity of the moricin. The transformation vector used in this study has already been created in this lab for the expression in both prokaryotic systems such as E. coli and chloroplast. The expressed moricin was purified using Ni columns and SUMOase, and the antibacterial activity of the purified moricin was confirmed using an agar diffusion assay.

• Korean Journal of Poultry Science
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• v.19 no.1
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• pp.27-34
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• 1992

Seventy-five commercial male day-old broiler chicks were used to investigate the effects of Oxytetracycline(OTC) and Lonicera japonica Thunberg(LJT) to be active in anti-bacteria and anti-virus on the growth rate, carcass rate and various intestinal organs sizes in broiler at 3 wk of age. Five experimental diets were formulated to have similar protein and energy levels, with OTC 0.04％ as low-level antibiotics and OTC 0.34％ as high-level antibiotics and 0.5％, 1.0％, 3.0％ level of LJT. Birds were housed randomly in 15 battery cages. Birds were 3 replicates per treatment and 5 chicks per replicate. In the body gain, 0.5％ level of LJT addition grew significantly higher than the other birds. The feed intake and feed efficiency were not significantly between other birds. The addition levels in OTC and LJT did not any consistent effect on the carcass rate. However, the chest meat percentage vs carcass volume in LJT 0.5％ treatment and the leg meat percentage vs carcass volume in DTC 0.04％ addition level were significantly higher than those of birds fed other diets. The liver weight rate was significantly higher in OTC 0.04％ level. However, the 0％ and LJT levels did not exert any consistent effect on the weights of gizzard, heart, bursa of fabricius, head and spleen of broilers. The abdominal and gizzard surrounding fat content rate was higher in bird LJT 1.0％ level than birds fed other levels.

• Journal of Yeungnam Medical Science
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• v.10 no.1
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• pp.190-196
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• 1993

The prognosis of chronic hepatitis C is very variable. In some, the disease is progressive and cirrhosis can develop from chronic hepatitis C. Hepatitis C virus(HCV) may act as a trigger towards hepatocellular carcinoma in patients with cirrhosis. Interferon has been used for the treatment of chronic hepatitis C in abroad, 16 patients with chronic C liver disease were treated with ${\alpha}$-interferon (alfa-2b; "Intron A" Schering Corp. Kenilworth. NJ). All patients were given ${\alpha}$-interferon in subcutaneous doses of 3 million units three times weekly for 1 to 9 months. During therapy, CBC and ALT levels were checked weakly to monthly. After therapy, patients were followed for 1 to 8 months. Among 16 patients treated with ${\alpha}$-interferon, progressive decrease of ALT levels was observed in 14(87.5%). In 11 patients(68.8%), ALT levels fell into the normal range during therapy, and in 9 of 11, within one month after therapy, 6 months after the completion of therapy in 4 of 9 patients(44.4%) whose ALT levels were in the normal range, ${\alpha}$-interferon seems to have effect in controlling disease activity in patients with chronic hepatitis C. But the changes in the usage of ${\alpha}$-interferon, dose and duration, long term follow up and more convenient and simple tests for HCV detection are recommended for the better effect and the exact evaluation on the effect of ${\alpha}$-interferon therapy in patients with chronic hepatitis C.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.80-87
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• 1999

Purposes : Renal involvement is a potentially serious complication of systemic lupus erythematosus (SLE). There have been only few studies of lupus nephritis in pediatric age. In this study, the clinical manifestations, pathologic findings, response to treatment, and clinical course of lupus nephritis in children were analyzed. And the results will provide basic data for future nation-wide prospective multi-center study. Methods . The medical records of 46 children clinically and pathologically diagnosed to have lupus nephritis at Seoul National University Children's Hospital during 1986 to 1997 were analyzed retrospectively. Results : 1) The median age of diagnosis of lupus nephritis was 12.8 years ($2\;years\~\;15year$ 8months), and the sex ratio was 1:2.5. 2) FANA($85.7\%$), anti-ds-DNA antibody ($78.0\%$), and malar rash ($60.8\%$) were the most common findings among the classification criteria by ARA Decreased C3 was detected in $88.9\%$ of patients. 3) Hematuria ($87.0\%$) was the most common renal symptom, and WHO class IV lupus nephritis was identified in 41 cases by renal biopsy. 4) In most of patients, the disease activity was controlled relatively well with a single or combined therapy of prednisolone, azathioprine, or cyclophosphamide. The response revealed no difference according to the mode of treatment. 5) Infection, especially of Varicella-Zoster virus and candida, was the most common complication during the disease course. Conclusion : The renal involvement was noted in $87.0\%$ of childhood SLE, and $89.1\%$ of renal lesions was WHO class IV lupus nephritis known to associated with poor long-term prognosis. So, aggressive treatment using immunosuppressants in the early disease course may be helpful to increase long-term prognosis of lupus nephritis. A prospective multi-center study is necessary to analyze the therapeutic efficacy of various treatment modalities.

• Journal of the Korean Society for information Management
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• v.39 no.1
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• pp.331-350
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• 2022

This study aims to understand topics of incivility related to COVID-19 from analyzing Twitter posts including COVID-19-related hate speech. To achieve the goal, a total of 63,802 tweets that were created between December 1st, 2019, and August 31st, 2021, covering three targets of hate speech including region and public facilities, groups of people, and religion were analyzed. Frequency analysis, dynamic topic modeling, and keyword co-occurrence network analysis were used to explore topics and keywords. 1) Results of frequency analysis revealed that hate against regions and public facilities showed a relatively increasing trend while hate against specific groups of people and religion showed a relatively decreasing trend. 2) Results of dynamic topic modeling analysis showed keywords of each of the three targets of hate speech. Keywords of the region and public facilities included "Daegu, Gyeongbuk local hate", "interregional hate", and "public facility hate"; groups of people included "China hate", "virus spreaders", and "outdoor activity sanctions"; and religion included "Shincheonji", "Christianity", "religious infection", "refusal of quarantine", and "places visited by confirmed cases". 3) Similarly, results of keyword co-occurrence network analysis revealed keywords of three targets: region and public facilities (Corona, Daegu, confirmed cases, Shincheonji, Gyeongbuk, region); specific groups of people (Coronavirus, Wuhan pneumonia, Wuhan, China, Chinese, People, Entry, Banned); and religion (Corona, Church, Daegu, confirmed cases, infection). This study attempted to grasp the public's anti-citizenship public opinion related to COVID-19 by identifying domestic COVID-19 hate targets and keywords using social media. In particular, it is meaningful to grasp public opinion on incivility topics and hate emotions expressed on social media using data mining techniques for hate-related to COVID-19, which has not been attempted in previous studies. In addition, the results of this study suggest practical implications in that they can be based on basic data for contributing to the establishment of systems and policies for cultural communication measures in preparation for the post-COVID-19 era.