• Korean Journal of Radiology
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• v.23 no.2
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• pp.180-188
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• 2022

Objective: To validate the performance of 3T spin-echo echo-planar imaging (SE-EPI) magnetic resonance elastography (MRE) for staging hepatic fibrosis in a large population, using surgical specimens as the reference standard. Materials and Methods: This retrospective study initially included 310 adults (155 undergoing hepatic resection and 155 undergoing donor hepatectomy) with histopathologic results from surgical liver specimens. They underwent 3T SE-EPI MRE ≤ 3 months prior to surgery. Demographic findings, underlying liver disease, and hepatic fibrosis pathologic stage according to METAVIR were recorded. Liver stiffness (LS) was measured by two radiologists, and inter-reader reproducibility was evaluated using the intraclass correlation coefficient (ICC). The mean LS of each fibrosis stage (F0-F4) was calculated in total and for each etiologic subgroup. Comparisons among subgroups were performed using the Kruskal-Wallis test and Conover post-hoc test. The cutoff values for fibrosis staging were estimated using receiver operating characteristic (ROC) curve analysis. Results: Inter-reader reproducibility was excellent (ICC, 0.98; 95% confidence interval, 0.97-0.99). The mean LS values were 1.91, 2.41, 3.24, and 5.41 kPa in F0-F1 (n = 171), F2 (n = 26), F3 (n = 38), and F4 (n = 72), respectively. The discriminating cutoff values for diagnosing ≥ F2, ≥ F3, and F4 were 2.18, 2.71, and 3.15 kPa, respectively, with the ROC curve areas of 0.97-0.98 (sensitivity 91.2%-95.9%, specificity 90.7%-99.0%). The mean LS was significantly higher in patients with cirrhosis (F4) of nonviral causes, such as primary biliary cirrhosis (9.56 kPa) and alcoholic liver disease (7.17 kPa) than in those with hepatitis B or C cirrhosis (4.28 and 4.92 kPa, respectively). There were no statistically significant differences in LS among the different etiologic subgroups in the F0-F3 stages. Conclusion: The 3T SE-EPI MRE demonstrated high interobserver reproducibility, and our criteria for staging hepatic fibrosis showed high diagnostic performance. LS was significantly higher in patients with non-viral cirrhosis than in those with viral cirrhosis.

• JOURNAL OF ELECTRICAL WORLD
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• s.458
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• pp.53-55
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• 2015

국토교통부는 '건축물의 에너지절약 설계기준'과 관련해 지난해 9월, 12월 두 차례 개정하고 시행에 들어갔다. 이 기준은 건축물의 효율적인 에너지관리를 위해 열손실 방지 등 에너지절약 설계에 관한 기준, 에너지절약계획서 및 설계 검토서 작성기준, 녹색건축물의 건축을 활성화하기 위한 건축기준 완화 등에 관한 사항을 담고 있다. 특히 9월 개정에서는 LED조명 설치 확대, 에너지성능지표(EPI) 전기부문 검토항목 추가 등 전기부문에 대한 내용이 다수 포함돼 있어 관계자들의 관심이 요구된다. 개정내용 중 전기부문에 대해 자세히 해설한다.

• Journal of Environmental Science International
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• v.7 no.3
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• pp.409-413
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• 1998

Polyamine was synthesized for the drinking water treatment. Polyamine was produced by the two step polycondensation of dimethytamine(DMA) and epichlorohydrin(EPI) and its properties were characterized. The effects of mole ratio of (DMA1/1EPl), reaction temperature and reaction time on synthesis of polyamine were investigated. Polyamine flocculant was applied to Nak-dong river raw water to examine its efficiency in reducing turbidity. The synthesized polyamine was effective as flocculant for drinking water treatment. The addition of 1 mg/L of polyamlne flocculant caused the reduction of 50% PAC (polyaluminium chloride).

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.13-16
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• 2000

A quantum-wire field effect transistor(QW-FET) using asymmetric double InGaAs channel and Si-delta doped barrier has been fabricated. It exhibited good modulation and saturation characteristic in the range of ${\mu}\textrm{A}$ current level. For estimated channel width of 150nm QW-FET, maximum transconductance was about 400 mS/mm which is higher than a conventional heterostructure FET(HFET) with the same epi-structure.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.165-165
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• 2001

Purpose： To obtain quantitative diffusion-tensor anisotropy information of human cerebral structu using turbo STEAM diffusion-tensor imaging. Method： Quantitative diffusion anisotropy MR images were obtained in 7 healthy adults using turbo STEAM sequence and a combination of tetrahedral and orthogonal diffusi gradients. Both relative anisotropy(RA) and fractional anisotropy(FA) values were measured various brain regions. The anisotropy index was then compared with the reported valu resulting from EPI-based diffusion tensor imaging.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.138-138
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• 2001

Purpose： To obtain quantitative diffusion-tensor anisotropy information of human cerebral structu using turbo STEAM diffusion-tensor imaging. Method： Quantitative diffusion anisotropy MR images were obtained in 7 healthy adults using turbo STEAM sequence and a combination of tetrahedral and orthogonal diffusi gradients. Both relative anisotropy(RA) and fractional anisotropy(FA) values were measured various brain regions. The anisotropy index was then compared with the reported valu resulting from EPI-based diffusion tensor imaging.

• Proceedings of the KSMRM Conference
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• 1996.10a
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• pp.70-70
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• 1996

• Proceedings of the KSMRM Conference
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• 1997.10a
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• pp.27-27
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• 1997

• Proceedings of the KSMRM Conference
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• 1997.10a
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• pp.49-49
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• 1997

• Kyungpook Mathematical Journal
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• v.18 no.1
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• pp.71-78
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• 1978

Consider the following commutative square of-categories and functors where T and U are (regular epi. monosource) topological and fibre small. G is algebraic and the following two conditions hold: (i) if h: $UA{\rightarrow}UB$ and g: $VA{\rightarrow}VB$ are morphisms such that Gh=Tg. there exists a morphism f: $A{\rightarrow}B$ such that Uf=h and Vf=g; (ii) U-initial monosources are carried into T-initial monosources by V.