• Investigative Magnetic Resonance Imaging
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• v.17 no.3
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• pp.169-180
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• 2013

Purpose : The purpose of this study was to setup a concuurent transcranial magnetic stimulation (TMS)-functional MRI (fMRI) system for understanding causality of the functional brain network. Materials and Methods: We manufactured a TMS coil holder using nonmagnetic polyether ether ketone (PEEK). We simulated magnetic field distributions in the MR scanner according to TMS coil positions and angles. To minimize image distortions caused by TMS application, we controlled fMRI acquisition and TMS sequences to trigger TMS during inter-volume intervals. Results: Simulation showed that the magnetic field below the center of the coil was dramatically decreased with distance. Through the MR phantom study, we confirmed that TMS application around inter-volume acquisition time = 100 miliseconds reduced imaging distortion. Finally, the applicability of the concurrent TMS-fMRI was tested in preliminary studies with a healthy subject conducting a motor task within TMS-fMRI and passive motor movement induced by TMS in fMRI. Conclusion: In this study, we confirmed that the developed system allows use of TMS inside an fMRI system, which would contribute to the research of brain activation changes and causality in brain connectivity.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.1-12
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• 2017

A natural hybrid of interspecific between the Coreoleuciscus splendidus and C. aeruginos (Cypriniformes: Cyprinidae) was captured in the Hwang-ji Stream, a tributary of the Nakdong River basin in Korea. An interspecific hybrid between C. splendidus and C. aeruginos was genetically identified based on morphological characteristics and the sequence analysis of nuclear recombination activating gene 1 (RAG1) gene (1,334 bp) and mitochondrial cytochrome c oxidase subunit 1 (CO1) gene (1,551 bp). As a result of morphological variations, the natural hybrid appeared to have an intermediate character between two parental species (C. splendidus and C. aeruginos) in three variations of black array (s) on dorsal, caudal and anal fin rays. Phylogenetic analysis inferred from RAG1 and CO1 sequence data revealed that Coreoleuciscus populations from Hwang-ji stream consist of two pure Coreoleuciscus species and a hybrid individual group. The individuals were clearly identified the cross and reciprocal hybrid by CO1 gene analysis. In RAG1 gene, 13 nucleotide variation loci were detected and the hybrid individuals displayed the double peaks of sequence chromatograms at the 9 diagnostic positions. In this study, molecular data and morphological variations were clearly demonstrated that hybridization did occur between C. splendidus and C. aeruginos. However, F2 hybrid generation and reproductive capacity of F1 hybrid individuals were not demonstrated.

• The Korean Journal of Mycology
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• v.29 no.1
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• pp.67-71
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• 2001

A steroid compound, F-l with antioxidative activity from the fruit bodies of Fomitella fraxinea was isolated by ethyl acetate extraction, silica gel column chromatography, and preparative silica thin layer chromatography. The structure of the compound was determined to be crgosta-7,22-diene-3-one-$16{\beta}-ol$ by IR, NMR, and GC-Mass. The compound exhibited inhibition on lipid peroxidation of rat liver microsomes, with $IC_{50}$ value of $3.8{\mu}g/ml$.

• Korean journal of applied entomology
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• v.20 no.1 s.46
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• pp.15-20
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• 1981

To analyze the inheritance of emergence rate of brown plant hopper (Nilaparvata lugens) biotypes, six crosses among biotype 1, biotype 2 induced by rearing on Mudgo and biotype 3 these on ASD 7, were made. Each generation $(P_1,\;P_2,\;F_l\; F_2,\;BC_1,\;BC_2)$ of each cross was fed on the rice seedlings of Mudgo and ASD 7 varieties. The emergence rate of biotpe 2 on Mudgo was controlled by the one incomplete dominant gene in $biotype\;l{\times}biotype$ 2 coross, however, that of biotype 3 on ASD 7 was controlled by one incomplete recessive gene in $biotype\;l{\times}biotype$ 3 cross. The genes involved in biotype 2 and biotype 3 were not identical, however, their allelic relations are not clear.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.89-98
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• 2006

Purpose : The prevalence of serotypes can be changed with respect to age of the patients, regions and times of the surveillance. The aim of this study is to analyze changes in serotype distribution of pneumococcal isolates from Korean pediatric patients. Methods : Four hundred and sixty five strains of S. pneumoniae were isolated from various clinical specimens at the Seoul National University Children's Hospital during a 15 year-period, from 1991 to 2005, were subjected to serotype and penicillin susceptibility. The study period was divided into three 5 year-periods, 1991~1995(period I), 1996~2000(period II), and 2001~2005(period III). Results : Common serotypes were 19F, 23F, 19A, 6B, 14, 6A and 9V in decreasing orders of frequency, and these 7 serotypes accounted for 79% of total 465 strains. In the serotype distribution of invasive infection isolates from children <60 months of age, similar serotypes accounted for 70% of 101 strains. In total strains, the proportion of serotype 19A and 6A increased, while that of serotype 19F and 14 decreased. The majority(75~92%) of vaccine types and cross-reactive types from invasive infection isolates was penicillin-resistant, whereas 34.4% of non-vaccine types was penicillin-resistant. Conclusion : Distribution of serotypes of S. pneuomoniae isolated from Korean children has changed significantly over the last 15 years. The surveillance for pneumococcal serotypes should be continued to monitor changes in serotype distribution which are essential for the establishment of pneumococcal vaccine policy.

• Science of Emotion and Sensibility
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• v.5 no.2
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• pp.23-28
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• 2002

The purpose of this study was to classify apparel fabrics according to rustling rounds and to analyze their transformed colors and mechanical properties. The rustling sounds of apparel fabrics were recorded and then transformed into colors using Mori's color-transforming program. The specimens were clustered into five groups according to sound properties, and each group was named as ‘Silky’,‘Crispy’,‘Paper-like’,‘Worsted’, and ‘Flaxy’, respectively. The Silky consisted of smooth and soft silk fabrics had the lowest value of LPT, $\Delta$f, ARC , loudness(B) and sharpness(z). Their transformed colors showed lots of red portion and color counts. The Crispy with crepe fabrics showed relatively low loudness(z) and sharpness(B), but diverse colors and color counts were appeared. The Paper-like showed the highest value of LPT, $\Delta$f and loudness(z). The Worsted composed of wool and wool-Like fabrics showed high values of LPT, $\Delta$f, loudness(z) and sharpness(B). The transformed rotors of the Paper-like and Worsted showed the blue mostly but color counts were less than the others. The Flaxy with rugged flax fabric had the highest fluctuation strength, and their transformed colors showed diversity.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.19-27
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• 2009

This study was conducted to investigate genetic characteristics of 25 Pleurotus eringii strains that have been released in Korea based on cultural, morphological features and PCR fingerprints. Strains PER-007 and PER-012 showed distinct cultural characteristics in growth rate, morphological characteristics of mycelial colony and fruiting bodies when compared to those of other strains. Strain PER-007 did not form primordium initiation in sawdust medium and PER-012 also showed different phenotypes on fruiting bodies. Eleven URP primers were used to detect PCR polymophic bands in P. eringii strains. Primers URP1F, URP2R, URP2F, URP4R, URP6R, URP9F and URP17R were selected as useful primers for amplifying PCR polymorphic bands in P. eringii strains. The genetic similarity index was calculated by using PCR polymorphic bands amplified by eight URP primers among the 25 strains. The P. eringii strains were grouped by four distinct clusters on the UPGMA analysis. The genetic similarity values ranged from 100% to 76% were observed in three major groups, suggesting close genetic relatedness of them. Exceptionally, PER-007 and PER-017 were involved in outgroup.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.373-376
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• 2005

본 연구에서는 뇌의 반응과 말초신경계의 변화를 통하여 유머와 기쁨의 긍정적인 정서의 구분이 가능한가를 밝히고자 하였다. fMRI와 말초신경계 반응 측정 실험 각각을 수행하는 동안, 유머와 기쁨정서를 유발하는 동영상 자극(2분)이 제시되었고, 실험이 끝난 후 심리적인 평가도 함께 수행되었다. fURI 실험은 boxcar design으로 한 session 내에 두 block으로 구성되었다. 말초신경계 반응실험에서는 안정상태와 정서상태에서의 피부전기 반응을 측정하였다. fMRI 결과, 유머자극과 기쁨자극 제시 시 공통적으로 precentral Cortex, temporal Cortex, precuneus 가 활성화 되었고, 유머자극은 기쁨자극에 비하여 우측 middle temporal cortex, 우측 inferior frontal cortex, 좌측 middle frontal cortex 에서 큰 활성화를 보였다. 피부전기 반응(EDA) 분석 결과 두 정서 모두 안정상태에 비하여 유의하게 증가하였고, 유머자극은 기쁨자극에 비하여 피부전도수준(SCL)과 피부전도반응의 수(NSCR)에서 유의하게 증가하는 것으로 나타났다.

• Journal of Applied Reliability
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• v.11 no.2
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• pp.141-149
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• 2011

Environment Conversion Factors, which are stipulated in System Reliability Toolkit, have a lot of advantages once applied in a reliability data handbook such as NPRD-95, during the process of reliability prediction. However, the factors have a restriction in their applications because they don't deal with a few environments, e.g., Missile Launch (ML). In this study, environment factors of various components from MIL-HDBK-217F were analyzed to address this problem. Statistical computations showed that converting from Airborne Rotary Wing (ARW) to Missile Launch (ML) was the most coherent by comparing coefficient of determination. In addition, conversion factors from System Reliability Toolkit and those from the statistical calculations were evaluated in terms of their similarities.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.422-423
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• 2007

In this work, Organic Light Emitting Diodes using LiF as a electron-injecting interfacial have been fabricated for efficiency enhancements. This interfacial layer is interposed between Al/$Alq_3$ layer. The brightness and specific character as current density are higher than those of the device without it. To find best thickness of LiF layer, we used some samples with various thickness. The LiF interposition at the Al/$Alq_3$ interface encouraged the electrons injection and balances the injection numbers of hole and electron in the emission layer.