• Title/Summary/Keyword: OK-gram

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DGA-based Botnet Detection Technology using N-gram (N-gram을 활용한 DGA 기반의 봇넷 탐지 방안)

  • Jung Il Ok;Shin Deok Ha;Kim Su Chul;Lee Rock Seok
    • Convergence Security Journal
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    • v.22 no.5
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    • pp.145-154
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    • 2022
  • Recently, the widespread proliferation and high sophistication of botnets are having serious consequences not only for enterprises and users, but also for cyber warfare between countries. Therefore, research to detect botnets is steadily progressing. However, the DGA-based botnet has a high detection rate with the existing signature and statistics-based technology, but also has a high limit in the false positive rate. Therefore, in this paper, we propose a detection model using text-based n-gram to detect DGA-based botnets. Through the proposed model, the detection rate, which is the limit of the existing detection technology, can be increased and the false positive rate can also be minimized. Through experiments on large-scale domain datasets and normal domains used in various DGA botnets, it was confirmed that the performance was superior to that of the existing model. It was confirmed that the false positive rate of the proposed model is less than 2 to 4%, and the overall detection accuracy and F1 score are both 97.5%. As such, it is expected that the detection and response capabilities of DGA-based botnets will be improved through the model proposed in this paper.

Brain-Waves Analysis according to Ego-state and OK-gram of Transactional Analysis Theory (교류분석이론의 자아상태와 인생태도에 따른 뇌파 분석)

  • Jeong, Cheon-Soo;Kim, Jung-Sam;Kim, Chong-Yeal
    • The Journal of the Korea Contents Association
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    • v.14 no.11
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    • pp.858-863
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    • 2014
  • Through this study, we found out whether to measure objectively by using Transactional Analysis(TA) evaluating their own growth and benefit of health through the change of Ego-state, the personality structure and brain waves monitoring electric signals occurring in the brain of the human biological signals. According to the results of brain-wave test, M-type is brain-waves of healthy adults and a, ${\beta}$ were dominantly observed in the occipital while not sleeping. In particular, ${\beta}$ appears widely throughout the brain during nervous or concentrating metal activities and unlike N-type experimenters, ${\beta}$ was found to be dominant in M-type experimenters even in stable condition. N-type is brain waves of healthy adults and a, ${\beta}$ were dominantly observed in the occipital while not sleeping. In particular, unlike nervous or concentrating M-type, there was no noise such as tension and blink while resting. In addition, it turned out that subjects with high levels of A ego do not return quickly to the stable state and show a lot of Blinking and swallowing saliva, noise regardless of the pattern of Egogram. And brain waves of 11 people that the difference in data of OK-gram and Ego-state is the same in all items or less than -5 showed a low amplitude of $20{\mu}V$ in general. In conclusion, this study identified that the theory of personality pattern of Transactional Analysis Theory and brain-wave findings are consistent and also found out that brain waves are also associated according to each Ego-state of Egogram.

Cytotoxity and Antimicrobial Effects of the Extract of Poncirus trifoliata (지실 추출물의 세포독성과 항균효과)

  • Yang Hyun-Ok;Oh Hyun-Ju;Park Nang-Kyu;Choi Eun-Young;Lee Hyun-Ok;Yang Eun-Yeong;Chun Hyun-Ja;Chung Soon-Ryang;Lee Kang-Min;Baek Seung-Hwa
    • Journal of Society of Preventive Korean Medicine
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    • v.4 no.2
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    • pp.235-241
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    • 2000
  • This study was carried out to evaluate cytotoxic effects of Poncirus trifoliata Raf. extract on lymphocytic leukemia tumor (L1210) cell lines. Disruptions in cell organelles were determined by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl-2H-tetrazoliumbromide (MTT) assay The comparison of Ic50 Values of Poncirus trifoliata Raf. extract in L1210 cell lines showed that their susceptibility to these fractons decreased in the following order: adriamycin > Fr.4> Fr. 6> Fr. 5> Fr. 3> Fr. 1> Fr. 2 by the MTT assay. In order to develop an antumicrobial agent, Poncirus trifoliata Raf. was extracted wit ethanol, and then it was fractionated with several mobile phase. The antitumor activities of fractions of the ethanol soluble extract was investigated. The minimal inhibitory concentrations (MIC) of fractions of the ethanol soluble extract of Poncirus trifoliata Raf. against microorganisms were also examined. Antimicrobial activities of ampicillin and ketoconazole as references were compared to those of fractions of the ethanol soluble extract of Poncirus trifoliata Raf. The antimicrobial activities of all fractions from the extract had growth inhibition activities against gram-positive bacteria, gram-negative bacteria and fungi $(MIC\;>\;200{\mu}g/ml)$. These results suggest that fraction 4 of the ethanol soluble extract of Poncirus trifoliata Raf. possessed the most antitumorous agent.

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Antimicrobial Characteristics of Different Parts of Guava against Food-Borne Bacteria (식중독 세균에 대한 구아바 부위별 추출물의 항균 특성)

  • Jo, Young-Hong;Ok, Dul-lee;Lee, Seung-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.12
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    • pp.1773-1778
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    • 2009
  • Guava (Psidium guajava L.) contains high amount of vitamins and minerals, and its leaves have been reported to be very effective on reducing blood pressure. In this study, antimicrobial characteristics of extracts from four different parts of guava (fruit, branch, leaf, and seed) with four different solvents (methanol, ethanol, acetone, and water) were evaluated. Four targeted food-borne microorganisms were selected; two Gram negatives (Escherichia coli O157:H7 and Salmonella Typhimurium) and two Gram positives (Staphylococcus aureus and Listeria monocytogenes). By the paper disc method, guava extracts showed stronger clear hollow zone against Gram positive bacteria than Gram negatives in nutrient broth agar plate. Especially, extracts of branches and leaves showed significant antibacterial activity. Guava extracts also showed significant inhibition activity on the growth of Gram positive food-borne bacteria in nutrient broth. For example, S. aureus did not grow at all at 200 ppm of acetone extracts of guava branch and leaf. In the case of L. monocytogenes, the same concentration of acetone extracts of guava branch and leaf inhibited the growth 33.5% and 55.4%, respectively, at 32 hrs of incubation time. The results indicated that extracts of guava branch and leaf showed significant antibacterial activities against food-borne Gram positive microorganisms, and that guava branches, the byproducts of guava, might be a valuable resource for antibacterial materials.

The Effects of Personality Traits on Stress Level, Stressor, and Stress Coping Style : Focused on S High School Students (성격특성이 스트레스 수준, 발생요인, 대처방식에 미치는 영향 : S고등학교 학생들을 중심으로)

  • Jo, Eun-Hyeon;Lee, Dong-Hyung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.3
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    • pp.107-115
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    • 2017
  • The purpose of this study is to find and compare the differences in stress level, stressor, and coping style of high school students according to their personality traits. And to identify the personality traits contributing to stress reduction. The results of the study can be used as basic data for reducing the stress of adolescents to improve their academic achievement and maintain mental and physical stability. The questionnaire survey was conducted for 10 days from June 7 to June 16, 2017 for S high school students in Chungbuk Province. The study employed four measuring instruments as Ego-gram, Ok-gram, stressor scale, and stress coping type scale. Individual personality traits were classified into ego-states and ok-states in TA (Transactional Analysis). Stressors are classified into 5 categories (school life, home life, human relationship, myself, environment) and stress coping styles are classified into 4 categories (problem-focused coping, social-support coping, feeling-focused coping, hope-thinking coping) used in the previous studies. The collected data were analyzed using T-test, ANOVA, and multiple regression analysis. As a result, the stress level of high school students showed significant differences according to sex, year, grade, sleeping time, personality traits, and coping styles. Personality traits that contributed to the stress increase were NP, AC, 'you positive', 'i negative' and personality trait that contributes to stress reduction is 'you negative.' Therefore, we can judge that individual personality traits have significant effects on stress level, stressor, and coping style and need to find the effective stress management method suitable for individual personality traits using counseling, repetition training, self-suggestion etc.

The Relationship between Microbial Characteristics and Glomalin Concentrations of Controlled Horticultural Soils in Gyeongnam Province

  • Kim, Min Keun;Ok, Yong Sik;Heo, Jae-Young;Choi, Si-Lim;Lee, Sang-Dae;Shin, Hyun-Yul;Kim, Je-Hong;Kim, Hye Ran;Lee, Young Han
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.2
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    • pp.107-112
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    • 2014
  • Glomalin has been suggested as an enhancer for soil stability by promoting the aggregation. In this study, we examined the concentrations of glomalin and microbial characteristics in 25 controlled horticultural soils sampled from Gyeongnam Province. Total glomalin had a significant positive correlation with soil organic matter (p < 0.01), soil microbial biomass carbon (p < 0.05), and dehydrogenase activity (p < 0.05) in controlled horticultural soils. In addition, the total glomalin had a significant positive correlation with concentrations of total fatty acid methyl esters, Gram-negative and Gram-positive bacteria, fungi, and arbuscular mycorrhizal fungi in controlled horticultural soils (p < 0.001). In conclusion, the concentration of total glomalin could be an indicator of microbial biomass richness for sustainable agriculture in controlled horticultural soils.

Molecular Differentiation of Bacillus spp. Antagonistic Against Phytopathogenic Fungi Causing Damping-off Disease

  • Cho, Min-Jeong;Kim, Young-Kwon;Ka, Jong-Ok
    • Journal of Microbiology and Biotechnology
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    • v.14 no.3
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    • pp.599-606
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    • 2004
  • Gram-positive antagonistic bacilli were isolated from agricultural soils for possible use in biocontrol of plant pathogenic fungi, Fusarium oxysporum, Rhizoctonia solani, and/or Pythium ultimum. Among the 65 antagonistic Gram-positive soil isolates, 22 strains were identified as Bacillus species by 16S rDNA sequence analyses. Four strains, including DF14, especially exhibited multiple antagonistic properties against the three damping-off fungi. Genotypic properties of the Bacillus isolates were characterized by rapid molecular fingerprinting methods using repetitive extragenic palindromic-PCR (REP-PCR), ribosomal intergenic spacer-length polymorphisms (RIS-LP), 16S rDNA PCR-restriction fragment length polymorphisms (PCR-RFLP), and strain-specific PCR assays. The results indicated that the REP-PCR method was more valuable than the RIS-LP and 16S rDNA PCR-RFLP analyses as a rapid and reliable approach for bacilli typing and identification. The use of strain-specific primers designed based on 16S rDNA sequence comparisons enabled it to be possible to selectively detect a strain, DF14, which is being used as a biocontrol agent against damping-off fungi.

Synthesis and Biological Activity of 3 - (Substituted) Tetrazolylmethyl Cephalosporins (3- (치환) 테트라조일메칠세파로스포린의 합성과 생리활성)

  • Ko, Ok-Hyun;Kim, Young-Soo;Ko, Bong-Suk;Lee, Jae-Young;Ha, Jai-Chun;Bang, Hee-Jae;Yoo, Jin-Cheol;Kang, Hyung-Ryong
    • YAKHAK HOEJI
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    • v.42 no.1
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    • pp.12-24
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    • 1998
  • For the development of new cephalosporin antibiotics with aminothiazolcarboxymethylethoxyimino moiety on the C-7 position and tetrazolymethyl moiety on the C-3 position of cephe m ring, 7${\beta}$-[(Z)-2-(2-aminothiazol-4-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[5-(substituted)tetrazol-2-yl]methyl-3-cephem-4-carboxylic acids(28-35) were synthesized. These compounds were tested for antimicrobial activity in vitro against Gram(+) and Gram(-) bacteria. They showed remarkable antibacterial activity against Escherichia coli AB 1157, Escherichia coli AB 0111, Escherichia coli BE 1186, Micrococcus luteus ATCC 9341, Salmonella typhimurium TV 119, Salmonella typhimurium SL 1102, Staphylococcus aureus IFO 12732, Staphylococcus aureus R-209, but these compounds were not active against Pseudomonas aeruginosa N-10.

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Study on patients of infectious diseases administered with vancomycin or teicoplanin - Assessment of fitness of antimicrobial administration - (감염증 환자에서 vancomycin, teicoplanin 투여례에 대한 연구 - 항균제 투여의 적응증 평가 -)

  • Chang, Chul Hun;Son, Han Chul;Hwang, Kyu Yon;Park, Kwang Ok;Yang, Ung Suk
    • Quality Improvement in Health Care
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    • v.3 no.2
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    • pp.26-35
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    • 1997
  • Background : Glycopeptide antibiotics are the only drugs for treatment of infections due to beta-lactam-resistant Gram-positive bacteria. As the incidence of infection and colonization with vancomycin-resistant enterococci(VRE) rapidly increases, the hospital infection control practices advisory committee(HICPAC) recommends prudent vancomycin use to detect, prevent and control infection and colonization with VRE. Methods : The inpatients admitted from September to December, 1996 in Pusan National University Hospital, with Gram-positive bacterial infections were evaluated retrospectively to see whether the administrations of glycopeptide antibiotics were appropriate or not, upon comparison with the recommendations for preventing the spread of vancomycin resistance by HICPAC. Results : Teicoplanin has been chosen more frequently than vancomycin of the glycopeptide antibiotics. The indications of administration of glycopeptides in patients with pneumonia, wound infections, sepsis, and in febrile or neutropenic patients with malignancies were appropriate, but the use of glycopeptides for elimination of merely colonized bacteria in the oral cavity could not be excluded. Inappropriate use of glycopeptides was 10.6%, and inappropriately long-term use without positive culture for beta-lactam-resistant Gram-positive organisms was about 40% of total days of drug use. Conclusion : It seems essential for the quality assurance committee to make a plan in teaching the HICPAC recommendations to the medical practitioners who prescribed the glycopeptides inappropriately or used for irrelevantly long to his patient, monitor and survey their use of glycopeptides prospectively and periodically, and if there are repeated inappropriate prescriptions, a certain penalty would be given to the practitioners.

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Study on Application of Lignum akebiae Main Blended Prescription from Dongeuybogam (동의보감(東醫寶鑑) 중(中) 목통(木通)이 주약(主藥)으로 배오(配伍)된 처방(處方)의 활용(活用)에 대한 고찰(考察))

  • Lee, Sang-Min;Kwon, Taek-Hyun;Ok, In-Soo;Yun, Young-Gab
    • Herbal Formula Science
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    • v.13 no.1
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    • pp.195-213
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    • 2005
  • This report describes the remedial fields, symptoms, pathology, dosage, prescriptional constitution of 46 studies related to the use of Lignum akebiae main blended prescriptions from Dongeubogam. The following conclusions were reached through investigations on the prescriptions that use Lignum akebiae as a key ingredient. Lignum akebiae blended prescriptions are utilized 17.4% of prescriptions appear in the chapter of urine. Prescriptions that utilize Lignum akebiae as the main ingredient are used commonly in the treatment of the symptoms of a urine and a cystic disease related to the urinary organs, or the diseases of eye, ear, nose, throat and the symptoms of a tumor, abscess. Lignum akebiae is utilized for an etiological and pathologenic fators related to heat, dampness, phlegm and summer heat such as excessive fever of heart and bladder, fever of small intestine, lower energizer dampness and heat, fever due to blood deficiency, phlegm fire, affection by summer heat and dampness etc. The clinical dosage of Lignum akebiae is 1 don(about 3.75gram), according to symptoms, it has ranged at a wide variety of amounts from 3 pun(about 1.13gram) to 1.5 don(about 11.25gram). Lignum akebiae is widely applied with base prescriptions such as Dozuksan, Moktongchajuntang, Manjunmoktongtang. etc.

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