• 대한수의학회지
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• 제39권4호
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• pp.811-818
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• 1999

A total of 16 Staphylococcus epidermidis isolates collected from 14 dogs admitted to the Veterinary Medicial Teaching Hospital in Seoul National University over eleven months were examined for in vitro antibiotic susceptibility pattern with minimum inhibitory concentration (MIC) and slime production, a virulence-associated phenotype, and were genetically characterized by pulsed-field gel electrophoresis (PFGE). The frequency of resistance to antimicrobial agents tested was not high, with a susceptibility ranging from 56.3% to 100%. Three strains exhibited multiple drug resistance against amikacin (MIC, $32-64{\mu}g/ml$), ampicillin ($32{\mu}g/ml$), fosfomycin ($32-128{\mu}g/ml$) and gentamicin ($16{\mu}g/ml$). Vancomycin, ciprofloxacin and rifampin were effective antibiotics against the isolates. All isolates were slime producers ; strains isolated from dogs which died of bacteremia were more likely to produce slime than those isolated from dogs which survived. Chromosomal DNA fingerprinting of the isolates yielded 16 different genomic types with few common bands, indicating a variety of clones of S epidermidis were prevalent in the hospital. This study revealed that PFGE is an useful method for the genotype characterization of S epidermidis strains and this organism could probably be pathogenic in some dogs with severe disorders. Further works on a larger number of epidemiologically defined strains are required to assess these results.

• 대한수의학회지
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• 제39권1호
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• pp.96-103
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• 1999

The present study was carried out to investigate the prevalence of mycoplasmal pneumonia of slaugter pigs in Youngnam area during the period from 1995 to 1997. The prevalence and pathomorphology of gross lung lesions were studied from 682 slaughter pigs in 8 swine herds. Gross lesions of pneumonia were recorded in the lungs of 442(64.8%), from 367 out of them(83.0%) were diagnosed as mycoplasmal pneumonia. Microbiological examination was performed with 197 lungs with gross lesions of mycoplasmal pneumonia of slaughter pigs from 8 different swine herds. M hyopneumoniae, P multocida, A pleuropneumoniae, Streptococcus spp, Corynebacterium spp, and H parasuis were detected in 24. 4%, 48.2%, 2.5%, 11.2%, 3.6%, and 1.0% of the pneumonic lungs, respectively. A total of 48 strains of M hyopneumoniae was investigated for their in vitro susceptibility to 8 antibiotics. Among the drugs tested, lincomycin, oxytetracycline, tiamulin and tylosin showed the high activity in minimal inhibitory concentration(MIC) of $0.04{\sim}5{\mu}g/ml$ while erythromycin showed low activity in MIC values($1.25{\sim}{\geq}40{\mu}g/ml$).

• 자원환경지질
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• 제27권4호
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• pp.411-420
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• 1994

Euiseong sub-basin, one of three sub-basins in Kyungsang basin, consists of various sedimentary and igneous rocks of Cretaceous age. Kusandong tuff and Yucheon volcanic rocks from the sub-basin were collected for the anisotropy of magnetic susceptibility (AMS) study. Maximum directions of the AMS for Kusandong tuff and Yucheon volcanic rocks are used to detect possible source areas. Although the dispersion of the maximum directions of the AMS, mainly due to low susceptibility and/or low percent anisotropy of individual specimens, is rather large, it is possible to reveal several source areas for the volcanic rocks. Areas near the Keumseongsan and Hwasan, calderas in the study area, are identified as source areas for Yucheon volcanic rocks, while the western part of Sunamsan, another collapsed caldera in Euiseong sub-basin, is inferred to be the source area for Kusandong tuff. However, it is not possible to determine detailed source areas for groups of Yucheon volcanic rocks of different lithologies, because of poor degree of convergence of the maximum directions of the AMS results from the volcanic rocks. It is also concluded that several episodic volcanic activities centered at Keumseongsan and Hwasan calderas were responsible for the formation of Yucheon volcanic rocks in Euseong area.

• 전기학회논문지
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• 제59권2호
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• pp.369-373
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• 2010

Modem electronic circuits are of importance for the function of communication, traffic systems and security systems. An intentional threat to these systems could be of big casualties and economic disasters. This paper has shown damage effect of microcontroller device with coupling caused by UWB-HPEM(Ultra Wideband-High Power Electromagnetics). The UWB measurements were done at an Anechoic Chamber using a RADAN UWB voltage source, which can generate a transient impulse of about 180 kV. The susceptibility level for microcontroller has been assessed by effect of various operation line lengths. The results of susceptibility analysis has showed that the effect of the reset line length on the MT(Ma1function Threshold) is larger than the effect of the different line length(Data, Power, Clock). With the knowledge of these parameters electronic system can be designed exactly suitable concerning the system requirements. Based on the results, susceptibility of microcontroller can be applied to protection plan to elucidate the effects of microwaves on electronic equipment.

• 한국지형학회지
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• 제24권2호
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• pp.91-101
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• 2017

Quantitative forecasting methods based on spatial data and geographic information system have been used in predicting the landslide location. This study compared the simulated results of logistic, Bayesian, and maximum entropy models to understand the uncertainties of each model and identify the main factors that influence landslide. The study area is Boeun gun where 388 landslides occurred in the year of 1998. The verification results showed that the AUC of the three models was 0.84. However, the landslide susceptibility distribution of Maxent model was different from those of the other two models. With the same landslide occurrence data, the result of high susceptible area in Maxent model is smaller than Logistic or Bayesian. Maxent model, however, proved to be more efficient in predicting landslide than the other two models. In Maxent's simulations, the responsible factors for landslide susceptibility are timber age class, land cover, timber diameter, crown closure, and soil drainage. The results suggest that it is necessary to consider the possibility of overestimation when using Logistic or Bayesian model, and forest management around the study area can be an effective way to minimize landslide possibility.

• 한국수산과학회지
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• 제53권6호
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• pp.870-877
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• 2020

Twenty-three Bacillus cereus strain isolated from commercial jeotgal were investigated for 11 toxin genes and susceptibility to 25 different antimicrobials. The hemolytic enterotoxins hblA, hblC, and hblD were detected in 13.0%, and non-hemolytic enterotoxins nheA, nheB, and nheC were detected in 26.1%, 100%, and 100% of the isolates, respectively. The positive rates of cytK, entFM, becT, hlyII, and ces were 73.9%, 60.9%, 26.1%, 8.7%, and 0.0%, respectively. According to the disk diffusion susceptibility test, all of the strains studied were resistant to cefuroxime, followed by cefoxitin (78.3%), oxacillin (78.3%), ampicillin (69.6%), penicillin G (69.6%), and amoxicillin (65.2%). However, all the strains were susceptible to 11 other antimicrobials, including amikacin, chloramphenicol, and ciprofloxacin. The average minimum inhibitory concentrations of amoxicillin, ampicillin, and cefuroxime against B. cereus were 462.9, 235.0, and 135.0 ㎍/mL, respectively. These results highlight the need for sanitizing commercial jeotgal, and provide evidence to help reduce the risk of jeotgal contamination by antimicrobial-resistant bacteria.

• Parasites, Hosts and Diseases
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• 제31권3호
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• pp.215-222
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• 1993

Toxoplasmngon gondii의 세포내 배양에 적합한 숙주 세포 주를 찾기 위하여 정상 세포 2종류(MDCK-canine kidney cells; Vero-monkey kidney cells) 및 암세포 6종류(A 549, PC 14-human lung cancer cells; SNU 1, SNU 16, MKN 45-human stomach cancer cells; HL-60-human promyelocytic leukemia cells)를 대상으로 하여 각 세포 주의 T.gondii 감염에 대한 감수성을 형태학적 관찰 및 3H-uracil 흡수 시험을 통하여 비교하였다. T.gondii 대한 감수성은 A 549 및 PC 14 세포가 가장 높았고, Vero, HL-60, MDCK 및 SNU 1 세포가 그 다음, SNU 16 및 MKN 45 세포는 가장 감수성이 낮았다. 또한 각 세포 주에 있어서 T.gondii 감염 후 충체증식 정도를 정량화하여 12시간, 36시간 및 60시간에 각각 측정한 바 충체 수를 적게($2{\times}10^5/ml$) 투여했을 때는 A 549, PC 14, Vero, MDCK 세포들에서 감염 60시간까지 충체의 분열 증식이 계속 증가하였고, 충체 수를 많이($50{\times}10^5/ml$) 주입하였을 때는 대부분의 세포들에서 감염 12시간에 최고의 증식을 보이다가 이후 증식이 감소하였다. 이상의 결과로 보아 기son사거 분리 계대 및 충주(strain) 확립을 위해서는 A 549 및 PC 14 세포가 가장 적합할 것으로 판단되며, 충체 주입 수 및 배양 시간별로 충체의 증식 정도가 다름을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4427-4433
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• 2013

Cervical cancer is the second most common cancer in women. HLA class I and II alleles polymorphisms have been shown to be associated with cervical cancer risk, but results have varied among different populations. In this study, the HLA-A, -B, and -DRB1 alleles among 100 southern Chinese women with cervical squamous cell carcinoma (SCC) were compared to 254 controls. Our results showed that $B^*51$:01:02 allele frequency was significantly higher in patients with SCC than in healthy controls ($P=3.17{\times}10^{-5}$, $P_c$=0.005, OR=26.7). Statistical analysis also revealed a significantly decreased frequency of $B^*51$:01:02 ($P=7.01{\times}10^{-4}$, $P_c$=0.03, OR=0.12) in patients with SCC when compared with healthy controls. These results indicate that HLA-$B^*51$:01:02 may confer susceptibility to SCC and HLA-$B^*51$:01:02 may contribute to resistance to the development of SCC in Chinese women. None of the HLA-A-B or HLA-A-B-DRB1 haplotypes were significantly different in cases and controls after multiple testing corrections, indicating the individual allele associations to be independent of the identified haplotypes. These results support the hypothesis that some HLA-B alleles could be involved with susceptibility for developing SCC.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.281-282
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• 1998

Recently, there has been growing interest in the assessment of physiological parameters on brain perfusion that provide more information than pure morphologic diagnosis. Quantification of parameters that characterize cerebral micro-circulation with magnetic resonance imaging is of great relevance for clinical application. We determine the local tissue concentration by exponential relationship between the relative signal reduction S(t)/$S_0$ and local tissue concentration of contrast material $C_m(t)$ in dynamic susceptibility contrast enhanced MR imaging. And then we made relative regional blood volume map by calculating the area under the measured concentration-time curves $C_m(t)$ during first pass of paramagnetic contrast material as a preliminary step for perfusion map. These images make it possible to compare the rCBV in different brain regions in one individual at a time. We have it in contemplation to obtain arterial and brain signal time curves simultaneously to make absolute rCBV and perfusion (rCBF) map. These maps may provide the method of comparative investigations of different patients having strong variation in AIF.

• Geomechanics and Engineering
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• 제25권1호
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• pp.1-16
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• 2021

Machine learning models have been widely used for landslide susceptibility assessment (LSA) in recent years. The large number of inputs or conditioning factors for these models, however, can reduce the computation efficiency and increase the difficulty in collecting data. Feature selection is a good tool to address this problem by selecting the most important features among all factors to reduce the size of the input variables. However, two important questions need to be solved: (1) how do feature selection methods affect the performance of machine learning models? and (2) which feature selection method is the most suitable for a given machine learning model? This paper aims to address these two questions by comparing the predictive performance of 13 feature selection-based machine learning (FS-ML) models and 5 ordinary machine learning models on LSA. First, five commonly used machine learning models (i.e., logistic regression, support vector machine, artificial neural network, Gaussian process and random forest) and six typical feature selection methods in the literature are adopted to constitute the proposed models. Then, fifteen conditioning factors are chosen as input variables and 1,017 landslides are used as recorded data. Next, feature selection methods are used to obtain the importance of the conditioning factors to create feature subsets, based on which 13 FS-ML models are constructed. For each of the machine learning models, a best optimized FS-ML model is selected according to the area under curve value. Finally, five optimal FS-ML models are obtained and applied to the LSA of the studied area. The predictive abilities of the FS-ML models on LSA are verified and compared through the receive operating characteristic curve and statistical indicators such as sensitivity, specificity and accuracy. The results showed that different feature selection methods have different effects on the performance of LSA machine learning models. FS-ML models generally outperform the ordinary machine learning models. The best FS-ML model is the recursive feature elimination (RFE) optimized RF, and RFE is an optimal method for feature selection.