• The Plant Pathology Journal
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• v.15 no.6
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• pp.313-318
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• 1999

Cloning of the 5'untranslated region (5' UTR) and Nterminus of the glycoprotein precursor (G2G1) open reading frame of tomato spotted wilt virus has been problematic, possibly because of the toxicity of a signal peptide at the beginning of th G2G1 protein precursor. The toxicity of the signal peptide to bacterial growth and the reason for the expression of the peptide gene in Escherichia coli were investigated by cloning the 5' UTR and the signal peptide sequence separately. Cells transformed with the plasmid containing both the first 30 amino acids of the glycoprotein and the 5' UTR showed a severe growth inhibition whereas transformants harboring either the plasmid with the signal sequence or the 5'UTR alone did not show any ingibition. An E. coli promoter-like sequence was found in the 5'UTR and tis promoter acivity was confirmed with a promoter-less GUS gene cloned downstream of the 5'UTR. In the cloning of the Tomato spotted wilt virus (TSWV) glycoprotein G2G1 open reading frame all the recovered plasmids contained stop codons in the signal sequence region. However, clones containing no stop codon were recovered when the signal sequence and the 5'UTR were cloned separately.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.4
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• pp.147-152
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• 2018

Underwater transient signals are complex, variable and nonlinear, resulting in a difficulty in accurate modeling with reference patterns. We analyze one type of underwater transient signals, in the form of whale sounds, using the MFCC(Mel-Frequency Cepstral Constant) and synthesize them from the MFCC and the weighted $L_2$-norm minimization techniques. The whales in this experiments are Humpback whales, Right whales, Blue whales, Gray whales, Minke whales. The 20th MFCC coefficients are extracted from the original signals using the MATLAB programming and reconstructed using the weighted $L_2$-norm minimization with the inverse MFCC. Finally, we could find the optimum weighted factor, 3~4 for reconstruction of whale sounds.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.253-259
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• 2015

The information of contrast media concentration on target organ is very important to get reduce the side effect and high contrast imaging. We investigated alternation of signal intensity as a function of the modality of Gd-based contrast media on spin echo and ultra short time echo (UTE) of T1 effective pulse sequence at 3T MRI unit. Gadoxetic acid, which is a MRI T1 contrast medium, was used to manufacture an agarose phantom diluted in various molarities, and sterile water and agarose 2% were used as the buffer solution for the dilution. The gold standard T1 calculation was based on coronal single section imaging of the phantom mid-point with 2D Inversion recovery spine-echo pulse sequence MR imaging for testing of phantom accuracy. The 1-2mmol/L and 7mmol/L was shown the maximum signal intensity on spin echo and UTE respectively. We confirm the difference of contrast media concentration which was shown the maximum signal intensity depending on the T1 effective pulse sequence.

• Progress in Medical Physics
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• v.21 no.1
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• pp.70-77
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• 2010

This study tested how S/N (Signal to Noise Ratio) ratios and ADC (apparent diffusion coefficient) values vary with different T-scores in a group of patients with osteoporosis. Based on DEXA (Dual Energy X-ray Absorptiometry) T-scores for L1.L4 for two groups of subjects consisting of 30 healthy people without osteoporosis and 30 patients who came for treatment of waist (lumbar or low back) pain and were suspected to have osteoporosis as judged from the simple X-ray findings, this study classified every spine into two groups of osteoporosis and osteopenia. Signal intensity measurements were made in the four regions of L1 to L4 on diffusion-weighted MR images obtained using 1.5T MR scanner, while ADC measurements were obtained from ADC map images. As an approach for quantitative analysis, the comparison of the variances in S/N ratios and ADC values for varying T-scores in the selected regions of interest was carried out based on averaged T-scores, S/N ratios, and ADC values. Also, the variances in S/N ratios and ADC values for each of the groups of osteoporosis and osteopenia, which were classified into by T-scores, were compared. For qualitative analysis, a careful naked eye examination of signal intensity differences in the area of L4 was made on T1-weighted sagittal images for each of the healthy (normal), osteopenia, and osteoporosis groups. In the qualitative analysis, it was found that for both the osteopenia group and the osteoporosis group, as T-scores deceased, the S/N ratios on diffusion-weighted MR images also decreased, with the greatest decrease in the S/N ratio found in the osteoporosis group. Additionally, among the three groups, the lowest S/N ratio was found in the osteoporosis group. With respect to ADC map, it was found that for both the osteopenia group and the osteoporosis group, as T-scores deceased, the ADC values on diffusion-weighted MR images also decreased, with the greatest decrease in the ADC values found in the osteoporosis group. Additionally, among the three groups, the lowest ADC value was found in the osteoporosis group. On the other hand, in the qualitative analysis, the osteoporosis group showed the highest signal intensity. Additionally, among the three groups, the lowest signal intensity was found in the healthy (normal) group. It was found that as osteoporosis progressed, S/N ratio and ADC decreased, whereas signal intensity increased on T1-weighted images. Also, in diagnosing osteoporosis, MRI tests turned out to be (more) effective.

• Proceedings of the Ginseng society Conference
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• 2006.05a
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• pp.76-76
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• 2006

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.2
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• pp.75-81
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• 1985

In low current injection level, the output signal of the 12 L is damaged and disturbed by the external loads (capacitance, resistance, current). Thus the uncertainty of the circuit can be increased .'This paper makes an analysis on the influences which the external loads have upon the 12 L-inverter function. It compares and analyzes the calculated result and measured result about the variation of rise time and fall time by means of computer simula-tions and experiments.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.2
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• pp.134-140
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• 2011

Recent work in compressed sensing theory shows that $M{\times}N$ independent and identically distributed sensing matrix whose entries are drawn independently from certain probability distributions guarantee exact recovery of a sparse signal with high probability even if $M{\ll}N$. In particular, it is well understood that the $L_1$-minimization algorithm is able to recover sparse signals from incomplete measurements. In this paper, we propose a novel sparse signal reconstruction method that is based on the reweighted $L_1$-minimization via support detection.

• Journal of the Korean Magnetic Resonance Society
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• v.4 no.2
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• pp.116-124
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• 2000

Singular value decomposition (SVD) has been used during past few decades in the advanced NMR data processing and in many applicable areas. A new modified SVD, piecewise polynomial truncated SVD (PPTSVD) was developed far the large solvent peak suppression and noise elimination in U signal processing. PPTSVD consists of two algorithms of truncated SVD (TSVD) and L$_1$ problems. In TSVD, some unwanted large solvent peaks and noises are suppressed with a certain son threshold value while signal and noise in raw data are resolved and eliminated out in L$_1$ problem routine. The advantage of the current PPTSVD method compared to many SVD methods is to give the better S/N ratio in spectrum, and less time consuming job that can be applicable to multidimensional NMR data processing.

• Journal of Yeungnam Medical Science
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• v.14 no.2
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• pp.337-349
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• 1997

This study was undertaken to examine the intensity of involvement of inducible nitric oxide synthase (iNOS) and cyclic GMP signal transduction pathway as one of the mechanisms of vaso-relaxative action of bacterial lipopolysaccharide (LPS) on the canine femoral artery strips. Canine femoral arteries were isolated and spiral strips of 10 mm long and 2 mm wide were made in the Tyrode solution of $0-4^{\circ}C$. The strips were prepared for isometric myography in Biancani's isolated muscle chamber containing 1 ml of Tyrode solution, which was maintained with pH 7.4 by aeration with 95% $O_2$/5% $CO_2$ at $37^{\circ}C$ and nitric oxide (NO) production was measured simulltaneously with isolated nitric oxide meter. LPS induced NO production, suppressed the phenylephrine (PE) induced contraction and enhanced the acetylcholine (ACh) induced relaxation. $N^G$-nitro-L-arginine methyl ester (L-NAME), an NOS inhibitor, methylene blue, a guanylyl cyclase inhibitor, potentiated PE induced contraction and suppressed ACh induced relaxation on the LPS treated strips. The inhibitory potency of methylene blue for LPS induced vascular hyporesponsiveness was stronger than that of L-NAME. These results suggest that in canine femoral artery, both iNOS and cyclic GMP signal trnasduction pathway are related with LPS induced vascular hyporeponsiveness, but in minor with iNOS and in major with cyclic GMP signal trnasduction pathway.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.479-485
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• 2011

To acquire images in a thermionic-scanning electron-beam system, a scanning unit is needed to control the electron beam emitted from the tungsten filament source. In scanning the electron beam on the solid surface, the signalto-noise ratio depends on the scanning frequency. We used a digital filter to reduce noise by analyzing the real-time frequency of a secondary electron signal. The noise and the true image signal were well separated. We designed the digital filter via a DSP floating-point operation, and the noise elimination resulted in enhanced image quality in a highresolution mode.