• Korean Journal of Medicinal Crop Science
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• v.1 no.1
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• pp.63-69
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• 1993

Present experiment were attempted to examine in vitro multiplication throughbud culture of Cornus officinalis. Bud derived shoot formation was established successfully on Murashige and Skoog's medium supplemented with $0.5mg\;/\;{\ell}$ BAP(N-benzyl amino purine). The shoot proliferation increased on the Driver Kuniyuki Walnut medium containing $0.5mg\;/\;{\ell}$ NAA(Napthalene acetic acid) and $0.5mg\;/\;{\ell}$ BAP. Addition of 2,4-D(2,4-Dichlorophenoxy acetic acid) to the media produced excessive callus inducton. IAA(Indole-3-acetic acid) and IBA (Indole-3-bu-tyric acid) enhanced multple shooting, and NAA showed callus induction and multiple shooting. Shoot growth was enhanced supplemented with 3% sucrose, $2g\;/\;{\ell}$ activated charcoal, and 1 / 4MS in organic salts. However, root formation of proliferated shoots was low about 5%

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.208-215
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• 1988

The leaf mesophyll protoplasts of Populus alba ${\times}$ glandulosa were isolated from leaf of plantlet in vitro and cultured for plant regeneration. The MS medium (minus $NH_4NO_3$) with 0.5 mg/l BAP and 2.0 mg/l 2, 4-D showed the moderate frequency of dividing protoplasts cultured by the liquid plating method during the first week of culture. The percentage of colony formation was revealed the highest frequency by the gauze contained semi-solid agar plating method after 5 weeks cultured. Ridding out the gauze, the micro-callus was formed on the same semi-solid medium in 8 weeks after protoplasts culture. For proliferation of callus, mini-callus was transferred on the MS solid medium with 0.5 mg/l 2, 4-D and 0.1 mg/l BAP 12 weeks after culture. Shoot regeneration occurred when the calli derived from protoplasts were cultured on MS medium with 1.0 mg/l zeatin and such shoots could be readily rooted on the one half strengthen MS medium with non-phytohormone. Rooting shoots were planted in green-house 22 weeks after protoplast culture.

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.291-302
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• 2011

The effects of roasting condition and storage time on rancidity of rapeseed oil were studied. Rapeseed oil from rapeseed roasted under different conditions were stored in the dark at $17^{\circ}C$. Volatile compounds of rapeseed oil were analyzed with an electronic nose (E-nose) and gas chromatography-mass spectrometry (GC-MS). The data from the E-nose were analyzed using discriminant function analysis (DFA). As roasting temperature increased from 150 to $240^{\circ}C$ over 20 min, the first discriminant function score (DF1) moved from positive to negative. DF1 decreased with storage time and changes in DF1 were higher between 0 and 2 days and between 20 and 24 days. Twenty-four compounds were identified in rapeseed oil, and hydrocarbons, furans, ketones, acids, benzene, and aldehydes were detected by GC-MS. The number of formed volatile compounds increased as storage time increased, but no increase in these compounds was detected by GC-MS.

• The Journal of Korean Society for School & Community Health Education
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• v.15 no.2
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• pp.91-101
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• 2014

Objectives: This study aimed to identify agreement between smartphone addiction (SA) and perceived SA among adolescents. Methods: This survey was done with 394 subjects conveniently sampled from elementary school (ES), middle school (MS), academic (AHS) and vocational (VHS) high school. The data were collected from June 20 to July 20, 2013 with self-administered questionnaire and analyzed by descriptive statistics, chi-square test and Cohen's kappa (${\kappa}$). Results: High risk of SA showed 2.8% in total, 1.0% in ES, 2.1% in MS, 4.1% in AHS, and 4.0% in VHS, which was statistically different by type of school (p<0.001). Perceived SA showed 22.6% in total, 9.0% in ES, 21.9% in MS, 33.7% in AHS, and 26.0% in VHS, which was statistically different by type of school (p=0.003). The agreement between SA and perceived SA was 82.0% (${\kappa}$=0.54) in total, 91.8% (${\kappa}$=0.53) in ES, 75.0% (${\kappa}$=0.33) in MS, 77.5% (${\kappa}$=0.53) in AHS, and 84.8% (${\kappa}$=0.65) in VHS. Conclusion: The agreement between SA and perceived SA showed moderate in general, but fair in MS. It is suggested to develop step-by-step activities to reduce the gap between SA and perceived SA among adolescen, in particular, middle school students.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.423-428
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• 2022

Very low contents (in the range of 10^-9 g/g) of Ir in mantle-derived rock samples (komatiites) were non-destructively determined by INAA coupled with coincidence gamma-ray spectrometry using 16 Ge detectors. Aliquots of the same samples were analyzed by NiS fire-assay ICP-MS for Ir and other platinum group elements. Because the INAA procedure used in this study is non-destructive and is almost free from spectral interference in gamma-ray spectrometry, the INAA values of Ir contents obtained in this study can be highly reliable. Iridium values obtained by ICP-MS were consistent with the INAA values, implying that the ICP-MS values of Ir obtained in this study are equally reliable. Under the present experimental conditions, detection limits were estimated to be 1 pg/g, which corresponds to 0.1 pg for a sample mass of 0.1 g. These levels can be even lowered by an order of magnitude, if necessary, which cannot be achieved by ICP-MS carried out in this study.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1C
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• pp.14-23
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• 2003

This thesis proposes a sigma-delta modulator architecture with 2 Ms/s data rate and 12 bit resolution. A sigma-delta modulate has the features of oversampling and noise shaping. With these features, it can be connected with low resolution A/D converter to achieve higher resolution A/D converter. Most previous researches have been concentrated on high resolution but low data rate applications, e.g. audio applications. But, in order to be applied to various applications such as wireless data communication, researches on sigma-delta modulator architecture for higher data rate are required. The proposed sigma-delta modulator architecture has the sampling rate of 16 times Nyquist rate to achieve high data rate, and consists of a cascade of two 2nd order sigma-delta modulator to get relatively high resolution. The experimental result shows that the proposed architecture achieves 12-bit resolution at 2 Ms/s data rate.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.157-162
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• 2009

High frequency plant proliferation system via direct frond regeneration of endemic duckweed plants Lemna paucicostata and Spirodela polyrhiza was established. Fronds of L. paucicostata and S. polyrhiza were able to multiply half-strength MS basal medium without plant growth regulators. However, addition of BA at a range of 1 to 3 mg/L was more effective than high concentration of BA treatments for fronds proliferation. Also half-strength MS salts was suitable for the fronds proliferation. Increase of salts concentration had inhibitory effect on fronds proliferation. Also the frequency of callus formation from fronds of L. paucicostata was 3.3%, when they cultured onto 1/2 MS medium supplemented with 1 mg/L of BA. Similarly the frequency of callus formation from S. polyrhiza was very low. After subculture of white globular structures derived from fronds of L. paucicostata, numerous globular somatic embryos and calluses were developed onto the surface of fronds. However these somatic embryos did not fully develop into normal plants when transferred to 1/2 MS basal medium. Therefore direct frond regeneration system was more efficient for mass proliferation of L. paucicostata and S. polyrhiza. The plant regeneration system of L. paucicostata and S. polyrhiza established in this study, might be applied to mass proliferation and genetic transformation for molecular breeding.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.2
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• pp.98-107
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• 2013

This work describes a 13b 100 MS/s 0.13 um CMOS four-stage pipeline ADC for 3G communication systems. The proposed SHA-free ADC employs a range-scaling technique based on switched-capacitor circuits to properly handle a wide input range of $2V_{P-P}$ using a single on-chip reference of $1V_{P-P}$. The proposed range scaling makes the reference buffers keep a sufficient voltage headroom and doubles the offset tolerance of a latched comparator in the flash ADC1 with a doubled input range. A two-step reference selection technique in the back-end 5b flash ADC reduces both power dissipation and chip area by 50%. The prototype ADC in a 0.13 um CMOS demonstrates the measured differential and integral nonlinearities within 0.57 LSB and 0.99 LSB, respectively. The ADC shows a maximum signal-to-noise-and-distortion ratio of 64.6 dB and a maximum spurious-free dynamic range of 74.0 dB at 100 MS/s, respectively. The ADC with an active die area of 1.2 $mm^2$ consumes 145.6 mW including high-speed reference buffers and 91 mW excluding buffers at 100 MS/s and a 1.3 V supply voltage.

• Analytical Science and Technology
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• v.19 no.1
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• pp.107-114
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• 2006

Early diagnosis and medical intervention are critical for the treatment of patients with metabolic disorders. A rapid analytical method was developed for simultaneous quantification of organic acids and amino acids in urine without labor-intensive pre-extraction procedure showing high sensitivity and specificity. A new method consisted of simple two-step trimethylsilyl (TMS)-trifluoroacetyl (TFA) derivatization using GC/MS-selective ion monitoring (SIM). Filter paper urine specimens were dried under nitrogen after being fortified with internal standard (tropate) in a mixture of distilled water and methanol. Methyl orange was added to the residue as indicator reagent. Silyl derivative of carboxylic functional group was followed by trifluoroacetyl derivative for amino functional group. N-methyl-N-(trimethylsilyl-trifluoroacetamide) and N-methyl-bistrifluoroacetamide were consecutively added and heated for 15-20 min at $65^{\circ}C-70^{\circ}C$, for TMS-TFA derivative, respectively. This reactant was analyzed by GC/MS-SIM. Linear dynamic range showed 0.001-50 mg with the detection limit of (S/N=3) 10-200 ng, and the quantification limit of 80-900 ng in urine. Correlation coefficient of regression line was 0.994-0.998. When the method was applied to the patients 'urine, it clearly differentiated the normal from the patient with metabolic disorder. The study showed that the developed method could be the method of choices in rapid and sensitive screening for organic aciduria and amino acidopathy.

• Plant Biotechnology Reports
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• v.3 no.1
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• pp.67-74
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• 2009

An efficient micropropagation protocol based on multiple shoot induction and callus regeneration has been standardized in Sarcostemma brevistigma, a rare medicinal plant. The nodal cuttings were cultured on MS medium supplemented with BA ($0.5-8{\mu}M$) or Kn ($0.5-8{\mu}M$) alone or in combination with NAA ($0.5-1.5{\mu}M$). Maximum multiple shoot induction was observed on MS medium supplemented with $4{\mu}M$ BA. On this medium, 100% cultures responded with an average number of 11.3 shoots per explant. However, the average shoot length was limited to only 0.9 cm on this medium. The addition of $1{\mu}M$ NAA along with $4{\mu}M$ BA gave rise to an average number of 10.9 shoots with an average shoot length of 1.8 cm. Luxuriantly growing callus was obtained on MS medium supplemented with BA ($5{\mu}M$) and 2,4-D ($2{\mu}M$). The callus was subcultured on MS medium supplemented with BA ($2-15{\mu}M$) or Kn ($2-15{\mu}M$) alone or in combination with NAA ($0.5-2{\mu}M$) for shoot organogenesis. Optimum callus regeneration was obtained on MS medium supplemented with $10{\mu}M$ BA and $1{\mu}M$ NAA. On this medium, 100% cultures responded with an average number of 13.4 shoots per culture. The shoots obtained via multiple shoot induction and organogenesis were rooted on half-strength MS medium supplemented with NAA ($1-7{\mu}M$) or IBA ($1-7{\mu}M$). IBA was better than NAA in terms of both the percentage of cultures that responded and the average number of roots per explant. The rooted shoots were successfully transplanted to soil with 86% success. This standardized protocol will help to conserve this rare medicinal plant.