• Proceedings of the Korea Concrete Institute Conference
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• 1990.10a
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• pp.63-67
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• 1990

The purpose of this study was to investigate the effects of flexural strength ratio(Mr=$\Sigma$Mc/$\Sigma$Mb) with High-Strength Concrete up to 800Kg/$\textrm{cm}^2$. Five specimens were tested under reversed cyclic loadings. The primary variables were flexural strength ratio of the beam-column, compressive strength of concrete and loading patterns. The results showed that the failure at the beam-column joint in case of high strength concrete was severe more than in case of normal strength concrete when flexural strength ratio 1.4. Thus the part for low limit of flexural strength ratio(Mr=1.4) should be revised for high strengthconcrete.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.224-233
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• 2012

The limiting sequence and relative ratio of lysine (Lys), methionine (Met), and threonine (Thr) for calves about 2 mo of age fed milk replacers (MR) containing soy protein are not clearly defined. The objective of the study was to investigate the effect of supplementing MR containing 22% CP, half from soy protein concentrate (SPC, 40.56% CP, flour) and half from whey proteins, with Lys, Met, and Thr to estimate amino acid (AA) sequence and their relative ratio for calves about 2 mo of age. A method of partial deduction of AA was adopted. Twenty-four newborn calves (half males and half females, $40.7{\pm}0.9$ kg of BW) were fed 1 of 4 MR diets for 56 d (n = 6/diet). The diets were supplemented with all (positive control) or with 2 of the 3 AAs: Lys, Met and Thr, (i.e., PC (22% CP, 2.34% Lys, 0.72% Met and 1.80% Thr), PC-Lys (22% CP, 1.64% Lys, 0.72% Met and 1.80% Thr), PC-Met (22% CP, 2.34% Lys, 0.50% Met and 1.80% Thr), and PC-Thr (22% CP, 2.34% Lys, 0.72% Met and 1.26% Thr)). Calves were fed thrice daily; starter (20% CP, 1.03% Lys, 0.30% Met and 0.69% Thr), hay (3.23% CP, 0.29% Lys, 0.12% Met and 0.23% Thr) and water were offered free choice. Starter and hay were only offered beginning on d 36 (after 5 wk) and d 43 (after 6 wk), respectively. BW, body size and blood samples measures were taken every two weeks. Three-day total collection of feed refusals, feces, and urine were recorded starting at d 33 and d 54 of age, respectively. From the results, the limiting sequence and relative ratio between the 3 AAs in calves with different diet structures were calculated. The limiting sequence of the 3 AAs were ranked as Lys, Met and Thr; the proper ratio was 100:29:70 for MR-only diet and 100:30:60 for diets consisted of MR, starter and hay. Nitrogen digestion and utilization and nutrient digestibility were negatively affected by AA deletion treatments. From the evidence of this experiment, it did not appear that the AA limiting sequence was selectively altered by differences in diet structures such as would be encountered in practice. The relative ratio between the 3 AAs varied with the offer of starter and hay to calves, and the average ratio was 100:29.5:65 for calves during 2 to 10 wk of age.

• The Journal of the Korean life insurance medical association
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• v.30 no.2
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• pp.12-15
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• 2011

Background: The beneficial effects of implantable cardioverter defibrillators (ICDs) in primary and secondary prevention patients are well established. However, data on potential differences between both groups in mortality are scarce. The aim of this study was to assess extra risk differences between primary and secondary prevention ICD recipients. Methods: Comparative mortality figures were calculated from a source article using mortality analysis methods. Results: Mortality ratio (MR) of primary and secondary prevention ICD recipients were 393% and 373%. Excess death rates (EDR) of both groups were 42 and 38 per 1,000. Discussion: MR and EDR were higher in primary prevention group. But, there was no significant difference.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.108-108
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• 2001

Purpose： To correlate the histological differentiation of hepatocellular carcinomas (HCCs) with finding on triple contrast-enhanced MR imaging using gadolinium-chelates, superparamganetic ire oxides (SPIO), and mangafodipir trisodium. Method： Ten patients with proven HCC underwent triple contrast-enhanced MRI befo surgical resection. Subjective ratings of the enhancement pattern and degree were compare with the histological grades determined on surgical specimen. Quantitative measurements signal-to-noise ratio (S/N) of the lesion and the lesion-to-liver contrast-to-noise ratio C/N on the enhanced MR images, and the degree of S/N and C/N changes between the unenhanced and enhanced images were also correlated with the histological grades.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.305-306
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• 1998

In this paper, we infer the onset of the brain infarction from the MR image using evaluate signal intensities on diffusion weighted and turbo spin echo T2-weighted and FLAIR images. Infarcts were divided into four stages (hyperacute, acute, subacute, chronic) depending on period of onset. DWI is useful for the detection of early ischemic infarct, and stages of ischemic infarctions can be estimated by evaluating CR(conspicuity ratio) and CNR(contrast to noise ratio) on DW, T2, FLAIR images Hyperacute infarcts were visualized DWI. Acute infarcts were visualialized both DWI and T2 Weighted image.

• Journal of Biomedical Engineering Research
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• v.18 no.1
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• pp.87-96
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• 1997

A pixel profile in the conventional DANTE sequence is so poor that the excited area by DANTE sequence is a small portion of a pixel. This causes poor signal to noise ratio in DANTE image. In this paper, a frequency modulated(FM) DANTE imaging sequence is proposed to improve pixel profile in DANTE image. A DANTE pulse train is shaped by an FM function so that all the spins within a pixel are excited, thereby improving the signal to noise ratio. It also shows that the pixel profiles are dependent on the sweep in FM signal. Computer simulations and experimental result obtained using a 7.0 T NMR imaging system are presented.

• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.167-172
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• 1999

Purpose : To evaluate the detection rate of hyperacute intracerebral hemorrhage in echo planar imaging (EPI) and other MR sequences. materials and Methods : Intracerebral hemorrhage was experimentally induced in ten rats. EPI, fast spin-echo (FSE) T2 weighted images, fluid attenuated inversion recovery (FLAIR), spin-echo (SE) T1 weighted images and gradient echo (GE) T1 weight ed images of rat's brains were obtained 2 hours after onset of intracerebral hemorrhage. EPI and FSE T2 images were additionally obtained 30 min and 1 hour after onset of hemorrhage in 3 and 6 rat, repeatedly, For objective visual assessment, discrimination between the lesion and normal brain parenchyma was evaluated on various MR sequences by three radiologists. For quantitative assessment, contrast-to-noise ratio (CNR) was calculated fro hemorrhage-normal brain parenchyma. Statistical analysis was performed usning the Wilcoxon-Ranks test. Results : EPI, FLAIR, and FSE T2 images showed high signal intensity lesions. The lesion discrimination was easier on EPI than on other sequences, and also EPI showed higher signal intensity for the subjective visual assessment. In quantitative evaluation, CNR of the hemorrhagic lesion versus normal brain parenchyma were higher on EPI and FLAIR images (p<0.01). There was no difference in CNR between EPI and FLAIR (p>0.10). On MR images obtained 30 minutes and 1 hour after the onset of intracerebral hemorrhage, the lesion detection was feasible on both EPI and FSE T2 images showing high signal intensity. Conclusion : EPI showed higher detection rate as compared with other MR sequences and could be useful in early detection and evaluation of intracerebral hemorrhage.

• Journal of the Korean Magnetics Society
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• v.14 no.6
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• pp.228-231
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• 2004

We have studied local magnetization reversal and magnetic properties induced by Laser annealing method in the strip-patterned Ta/NiFe/FeMn/Ta and Ta/NiFe/FeMn/NiFe/Ta multilayers fabricated by ion-beam deposition. The films were exposed to the emission of the DPSS (Diode Pumped Solid State, Nd:YAG) laser under 600 G. The laser beam intensity increased up to 440 mW. When the laser illuminated the patterned film with the power of above 200 m W, the intensity of MR peak located in +87 Oe shrunk. A new MR peak was generated at -63 Oe. When the laser power is 400 mW, the location of positive MR peak(H$\sub$ex/) was changed slightly from +87 Oe to +76 Oe, and the MR ratio was decreased from 0.9% to 0.1 %. On the other hand, the new (negative) MR peak shifted from -63 Oe to -80 Oe, with the MR ratio increased up to 0.3%. As the illuminated area expanded, the intensity of opposite MR peak increased and it of negative MR peak decreased. This proved that the local reversal of exchange biasing should be realized by laser annealing.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.37-37
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• 2003

To assess the merits and demerits of postcontrast fat-suppressed (FS) brain MR imaging in children in the evaluation of various enhancing lesions, compared with postcontrast conventional or Magnetization Transfer (MT) imaging. 대상 및 방법： We reviewed patients with enhancing lesion on brain MR imaging who underwent both FS imaging and one of conventional or MT imaging as a postcontrast T1-weighted brain MR imaging. Inclusion criteria of our study were as follows： MR studies should be peformed within one-year interval and showed no significant interval change of imaging findings. Thirty-four patients (21 male, 13 female; mean age, 8 years) with 43 enhancing lesions (19 intra-axial, 19 extra-axial, and 5 orbital location) were included in this study, Twenty-one pairs of FS and conventional imaging, and 15 pairs of FS and MT imaging were available. Two radiologists visually assessed the lesion conspicuity and the presence of flow or susceptibility artifacts in a total of 36 pairs of MR imaging by consensus. For 21 measurable lesions (19 pairs of FS and conventional imaging, 5 pairs of FS and MR imaging), contrast ratio between the lesion and the normal brain( ［SIlesion-SIwater］/[SInormal brain-SIwater]) were calculated and compared.

• Journal of the Korean Vacuum Society
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• v.5 no.3
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• pp.258-262
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• 1996

We have investigated the changes in magnetoresistive characteristics, interfacial roughness, and preferred orientation with the Fe buffer layer thickness, annealing temperature, and the stacking number of layers variation in Fe/[NiFe/Cu] multilayers by using the 3-gun d.c. magnetron sputtering method. Intensity of the (200) orientation was increased with the increment of the Fe-buffer layer thickness. We found a maximum magnetoresistance ration of 4.7%, when the buffer layer thickness was 70$\AA$, and the field sensitivity also showed a maximum value at the same thickness. We varied the stacking number of multilayers with fixing the Fe buffer layer thickness of 70$\AA$. When the stacking number was 40 layers, maximum MR ratio(5.3%) was observed. With the variation of annealing temperature no change in the MR ratio was found beyond $300^{\circ}C$. But decrement of MR ratio was observed above $300^{\circ}C$. This decrement of the MR ratio was responsible for the increment of paramagnetic mixed layer caused by the diffusion of Cu layer and the change of antiferromagnetic coupling.