• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1385-1391
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• 2010

In this study, we present small-size, low-power, and high-speed electromagnetic flapping shutters for phone cameras. These shutters are composed of trapezoidal twin blades suspended by H-type torsional springs. The existing electrostatic rolling and flapping shutters need high input voltage, while the existing electromagnetic rotating shutters are too big to be used for phone cameras. To achieve low-power and high-speed angle motion for small-size electromagnetic flapping shutters for camera phones, low-inertia trapezoidal twin blades, each suspended by the low-stiffness H-type torsional springs, are employed. The electromagnetic flapping shutters used in this experimental study have steady-state rotational angles of $48.8{\pm}1.4^{\circ}$ and $64.4{\pm}1.0^{\circ}$ in the magentic fields of 0.15 T and 0.30 T, respectively, for an input current of 60 mA; the maximum overshoot angles are $80.2{\pm}3.5^{\circ}$ and $90.0{\pm}1.0^{\circ}$ in the magentic fields of 0.15 T and 0.30 T, respectively. The rising/settling times of the shutter while opening are 1.0 ms/20.0 ms, while those while closing are 1.7 ms/10.3 ms. Thus, we experimentally demonstrated that the smallsize (${\sim}8{\times}8{\times}2\;mm^3$), low-power (${\leq}60\;mA$), and high-speed (~1/370 s) electromagnetic flapping shutters are suitable for phone cameras.

• Korean Journal of Community Nutrition
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• v.15 no.5
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• pp.694-703
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• 2010

Recent studies have reported that a subset of obese individuals who were metabolically healthy but obese had more favorable clinical outcomes than obese subjects with metabolic disturbances. The purpose of this study was to evaluate the distribution and agreement of obesity subtypes according to body mass index (BMI) and metabolic syndrome (MS). Furthermore, we examined the differences of nutrient intake among the groups. Data was analyzed for 1,095 female subjects older than 40 years using Korean National Health and Nutrition Survey in 2008. The degree of obesity was classified by two methods, using BMI (obese ${\geq}\;25\;kg/m^2$, not obese < $25\;kg/m^2$) and MS (meet ${\geq}\;3$ criteria among 5 index: waist circumference, triglyceride, glucose, HDL-cholesterol and blood pressure). Subjects were divided into 4 groups according to $2{\times}2$ cross table: non-obese without MS, non-obese with MS, obese without MS and obese with MS. Nutrient intakes were compared among 4 groups. The results showed that the proportions of non-obese without MS, non-obese with MS, obese without MS and obese with MS were 47.6%, 13.6%, 16.6%, and 22.2% of total subjects, respectively. The agreement (kappa value) of two methods was 0.354 (fair) in total subjects, 0.365 (fair) in 40-60 year old subjects and 0.304 (fair) in ${\geq}\;61$ year old subjects. In ${\geq}\;61$ years old subjects, intakes of percentage energy from carbohydrate, percentage of energy from fat, calcium, phosphorous, sodium, vitamin A, carotene, thiamine, riboflavin and niacin were significantly different among the groups. In contrast, the subjects of 40-60 years old, no differences in nutrient intakes were observed. In conclusion, there were differences in nutrient intakes among the groups subdivided by obesity and MS, especially in elderly female subjects. Individualized dietary guideline for subtype of obesity will be needed to treat metabolic disturbance of obesity.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.177-182
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• 2007

The objective of this study was to evaluate the genetic relationship between weaning weight (WW) and carcass traits. Carcass traits were eye muscle area(EMA), back fat thickness(BFT), marbling score 1(MS1) in 21 grade scales, marbling score 2(MS2) in 7 grade scales and meat color scores(Mcolor). Parameters were estimated by REML procedure with MTDFREML package. Models included contemporary group as defined by the same year-season-sex at birth, linear covariates of age(days) at weaning, age of dam(days) and age at slaughter(days) as fixed effects and animal random effects for all the traits. Heritability estimates of WW, EMA, BFT, MS1, MS2 and Mcolor were 0.25, 0.20, 0.20, 0.32, 0.32 and 0.22, respectively. Genetic(phenotypic) correlation coefficients of WW with EMA, BFT, MS1, MS2 and Mcolor were 0.75(0.16), 0.18(0.05), －0.41(－0.09), －0.40(0.11) and －0.07(0.05), respectively. Results from this study suggest that single trait selection for weaning weight would lead to progeny population having carcass with large EMA, thick BFT and decreased MS.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.1
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• pp.47-55
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• 2005

This work describes an 8b 240 MS/s CMOS ADC as one of embedded core cells for high-performance displays requiring low power and small size at high speed. The proposed ADC uses externally connected pins only for analog inputs, digital outputs, and supplies. The ADC employs (1) a two-step pipelined architecture to optimize power and chip size at the target sampling frequency of 240 MHz, (2) advanced bootstrapping techniques to achieve high signal bandwidth in the input SHA, and (3) RC filter-based on-chip I/V references to improve noise performance with a power-off function added for portable applications. The prototype ADC is implemented in a 0.18 um CMOS and simultaneously integrated in a DVD system with dual-mode inputs. The measured DNL and INL are within 0.49 LSB and 0.69 LSB, respectively. The prototype ADC shows the SFDR of 53 dB for a 10 MHz input sinewave at 240 MS/s while maintaining the SNDR exceeding 38 dB and the SFDR exceeding 50 dB for input frequencies up to the Nyquist frequency at 240 MS/s. The ADC consumes, 104 mW at 240 MS/s and the active die area is 1.36 ㎟.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.519-525
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• 2019

The Ministry of Food and Drug Safety (MFDS) is amending its test methods for health functional foods (dietary food supplements) to establish regulatory standards and specifications in Korea. In this regard, we are continuing our research on analytical method development for the items listed in the Korean Health Functional Food Codex. In this study, we have developed a sensitive and selective test method that could simultaneously separate and determine coenzyme Q10 based on liquid chromatographic-tandem mass spectrometry (LC-MS/MS). Calibration curves showed linearity with a correlation coefficient (R²) of > 0.999 and the limits of detection (LODs) and limits of quantitation (LOQs) were in the range of 26.0 ㎍/L and 78.9 ㎍/L, respectively. The recovery results ranged between 98.6-107.0% at 3 different concentration levels with relative standard deviations (RSDs) less than 5%. The proposed analytical method was characterized with high resolution of the coenzyme Q10 and the assay was fully validated as well.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.306-320
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• 2015

This survey was carried out in 2014 to estimate the pesticide residue levels in commercial environment-friendly agricultural products in Seoul metropolitan area. Pesticide residues in 27 commodities were examined and analyzed using LC-MS/MS, which can simultaneously detect up to 85 pesticides. A total of 441 samples were collected and analyzed. Among the detected samples, the residue levels in 1.2% of organic agricultural products and 2.2% of pesticide-free agricultural products exceeded the maximum residue limits (MRLs); hence, 1.8% of the total samples exceeded the MRLs. The safety of the detected pesticides was assessed by monitoring the acceptable daily intake level (ADI) and acceptable dietary exposure (ADE) to the pesticides via consumption of the commodities. ADI and ADE are found to be 0.07728-9.46530% and 0.00141-0.17210%, respectively, which means that the residual pesticides in the environmental-friendly agricultural products in Korea are below the safe limit and therefore, pose no potential public health risks.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.3
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• pp.77-85
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• 2008

This work proposes a 12b 130MS/s 108mW $1.8mm^2$ 0.18um CMOS ADC for high-quality video systems such as TFT-LCD displays and digital TVs requiring simultaneously high resolution, low power, and small size at high speed. The proposed ADC optimizes power consumption and chip area at the target resolution and sampling rate based on a three-step pipeline architecture. The input SHA with gate-bootstrapped sampling switches and a properly controlled trans-conductance ratio of two amplifier stages achieves a high gain and phase margin for 12b input accuracy at the Nyquist frequency. A signal-insensitive 3D-fully symmetric layout reduces a capacitor and device mismatch of two MDACs. The proposed supply- and temperature- insensitive current and voltage references are implemented on chip with a small number of transistors. The prototype ADC in a 0.18um 1P6M CMOS technology demonstrates a measured DNL and INL within 0.69LSB and 2.12LSB, respectively. The ADC shows a maximum SNDR of 53dB and 51dB and a maximum SFDR of 68dB and 66dB at 120MS/s and 130MS/s, respectively. The ADC with an active die area of $1.8mm^2$ consumes 108mW at 130MS/s and 1.8V.

• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.21-27
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• 1997

This experiments were conducted to determine the effect of thidiazuron on forming tuberlets and plant regeneration of Pinellia ternata T. by tissue culture. The addition of $5\;{\mu}M$ TDZ to the medium had better regeneration than that of any other treatments of NAA and TDZ. At the combination treatments of NAA and TDZ, as the level of thidiazuron increased, the rate of shoot regeneration was incresed while the increment of NAA concentration inhibited the rate of shoot regeneration. The supplement of $5\;{\mu}M$ thidiazuron produced the best number of micro-tubers per explant and the number of micro-tuber formed was 25 in MS medium and 29 in MG medium on 30 day culture, respectively. Microtuber formation was the best on MG medium with 1.0 mg/l NAA and $5\;{\mu}M$ thidiazuron. MG medium was superior to MS and B5 medium for the growth of tuberlets. Half strength of MS medium with NAA 2 mg/l was the most effective for root formation. Rooting ability on nursery soil of plantlets produced in in vjtro was good as a 80% after 3 weeks.

• Analytical Science and Technology
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• v.31 no.1
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• pp.39-46
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• 2018

Carbaryl and seven organophosphorous pesticides were analyzed simultaneously using on-line solid phase extraction (on-line SPE) coupled with liquid chromatography tandem mass spectrometry (LC/MS/MS). The target pesticides are Carbaryl, Methyl demeton, Fenitrothion, Malathion, Parathion, Phenthoate, Diazinon, and EPN. This method includes the direct injection of $500{\mu}L$ in the water sample, a 15 min separation period using a rapid resolution liquid chromatography system with on-line SPE, and detection through electrospray ionization (ESI) positive mode. The percentage of recovery of all pesticides ranged from 85.3 % to 100 %. This method showed an accuracy of ${\geq}90.0%$, possessing limits of detection and quantification within 0.05 to $0.28{\mu}g/L$ and 0.16 to $0.89{\mu}g/L$, respectively. The correlation coefficients (r) for the calibration curves within a range of 0.5 to $8.0{\mu}g/L$ were higher than 0.99. The evaluation results showed the efficacy of the method for all contents, and no pesticides were detected in the water quality sample.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.9-14
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• 1998

Two types of somatic embryos were directly induced from the immature zygotic embryos of the wild prunus yedoensis in Mt. Halla after 16 weeks of culture on MS medium supplemented with 0.1mg/L $GA_3$ and 0.1mg/L BAPor 0.5mg/L $GA_3$ and 0.1mg/L BAP. One was normal single embryo with a single basal part. Normal somatic embryos germinated successfully on 1/2 MS medium. However, abnormal nulticotyledonary somatic embryos, formed shoots only on hormone free MS medium and about 80% of shoots rooted on MS medium with 0.5mg/L IBA. The mximum frequency (62.5%) of normal somatic embryos was directly obtained from the zygotic embryo 30 days after full blooming but it was decreased with further maturation.