• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.1
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• pp.79-84
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• 2007

In this paper, a fully-integrated low phase noise multi-band CMOS VCO using automatic level controller (ALC) and switched LC tank has been presented. The proposed VCO has been fabricated in a 0.13-um CMOS process. The switched LC tank has been designed with a pair of capacitors and two pairs of inductors switched using MOS switch. By using this structure, four band (2.986 ${\sim}$ 3.161, 3.488 ${\sim}$ 3.763, 4.736 ${\sim}$ 5.093, and 5.35 ${\sim}$ 5.887 GHz) operation is achieved in a single VCO. The VCO with 1.2 V power supply has phase noise of -118.105 dBc/Hz @ 1 MHz at 2.986 GHz and -113.777 dBc/Hz @ 1 MHz at 5.887 GHz, respectively. The reduced phase noise has been approximately -1 ${\sim}$ -3 dBc/Hz @ 1 MHz in the broadest tuning range, 2.986 ${\sim}$ 5.887 GHz. The VCO has consumed 4.2 ${\sim}$ 5.4 mW in the entire frequency band.

• Journal of Information Display
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• v.2 no.3
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• pp.32-38
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• 2001

The most important parameter for TV application of LCD is a fast switching time for the display of moving image. To achieve faster switching time, the novel LC single materials with large dielectric anisotropies ($16{\sim}20$), high clearing temperatures ($195.5{\sim}237.4^{\circ}C$), broad nematic ranges (up to 169.9 $^{\circ}C$) and high birefringence ($0.254{\sim}0.2200$) were developed. KUR-series LC mixtures blended these single materials having significantly higher clearing temperatures and dielectric anisotropy values compared with conventional LC mixture. Especially, their clearing temperatures are $10{\sim}30^{\circ}C$ higher than their host mixture. These LC mixtures showing about lOms of high-speed switching time in Tv/Monitor of TFT LCD, is short enough to be addressed in a single time frame of 60Hz (16.7 ms). The threshold voltage $V_{th}$ was low enough to operate at a driving voltage of 5 V. The VHR values were found to be high enough for TFT-LCD in wide temperature range. Our novel LC mixtures are suitable materials for the inclusion in to LC mixtures for TV application of TN-LCD

• The Journal of Internal Korean Medicine
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• v.36 no.3
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• pp.217-227
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• 2015

Objectives: The primary aim of this study was to identify bioactive compounds in Dangnyo-hwan, a Korean herbal medicine, through instrumental analysis using LC-MS/MS and ICP, and investigate its potential use in diabetes treatment. Methods: The extract of Dangnyo-hwan has 12 medicinal herbs; these were compared with 18 marker substances selected from literature survey. Results: LC-MS/MS analysis could detect 9 of the 18 bioactive compounds: citruline, catalpol, berberine, ginsenoside Rb1, ginsenoside Rg1, oleanolic acid, β-sitosterol, mangiferin, and schizandrin. While harmful heavy metals such as As, Pb, Cd, Hg, Ni, and Cu were not present in high concentrations, Zn concentration was 4.2 mg in 100 g Dangnyo-hwan. Conclusions: Instrumental analysis such as LC-MS/MS and ICP was successfully used to identify bioactive compounds in Dangnyo-hwan. Detection of 9 bioactive substances and Zn from the herb medicine is a valuable finding, and suggests that Dangnyo-hwan is a candidate medicine for diabetes. Further investigations like in vitro assay, percent GPR 119 activity, and percent human DGAT-1 inhibition are underway.

• Journal of the Korean Applied Science and Technology
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• v.13 no.2
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• pp.29-37
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• 1996

The phase separated structure and the electo-optical properties of the polymer /liquid crystal(LC) composite films including a dye were investigated. The phase separated structure of the polymer /LC / dye composite film(GH composite film) including below 2wt% dye against LC was almost same with the composite film which does not include dye. But the electro-optical properties of the GH composite film strongly depended on weight fraction of the dye against the LC. The response time of the GH composite film increased with the increase of the dissolved dye in LC because the dye acts as a registivity for the orientation of LC molecules by the electric filed.

• Korean Journal of Optics and Photonics
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• v.5 no.3
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• pp.411-417
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• 1994

The electro-optic polarization transmission characteristics of a liquid crystal (LC) cell is represented by a rotational transformation on the Poincare sphere, and its characteristic parameters, the angle and the axis of the rotation, are experimentally determined with respect to the voltage applied to the LC cell. From the experimental data obtained, we determine driving voltage for the LC cell to give the rotation angle near $180^{\circ}$ of the rotation for the change of the state of the LC cell from non-select to select state, which is a necessary condition for the realization of maximally bright images. The directions of the transmission axes of the polarizer and the analyzer which form a liquid crystal display panel together with the LC cell, are determined from the general characteristics of the rotaional transformation of the LC cell. cell.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.131-138
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• 2007

In this paper, a novel nonlinear control method of the CVCF(constant voltage and constant frequency) output voltage for the three-phase PWM inverter with LC output filters is proposed. A nonlinear modeling including the output LC filters is linearized by feedback linearization theory, the controllers of which can be designed based on a linear control theory. It is applied to the DC/AC power conversion of the PWM inverter for stand-alone wind power generation system. It has been verified by the experimental results that the proposed control scheme gives high dynamic responses at load variation as well as a zero steady-state error.

• Natural Product Sciences
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• v.27 no.4
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• pp.293-299
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• 2021

The ethyl acetate fractions prepared from the leaves of Thuja orientalis significantly inhibited nitric oxide (NO) production in lipopolysaccharide-stimulated BV2 microglial cells. According to bioassay-coupled LC-QTOF MS/MS, the components near 22 and 25 mins in the mass chromatogram highly inhibited NO production and were expected to be labdane diterpenes, and the active components were characterized via further isolation. The results of the NO production inhibitory assay of the isolated compounds correlated well with the results of bioassay-coupled LC-QTOF MS/MS. Among the identified constituents, NO production inhibitory activities of 16-hydroxy-labda-8(17),13-diene-15,19-dioic acid butenolide (2) and 15-hydroxypinusolidic acid (3) were newly reported. Taken together, these results demonstrated that LC-QTOF MS/MS coupled with NO production inhibition assay was a powerful tool for accurately predicting new anti-inflammatory constituents in the extracts from natural products. Moreover, it provided a potential basis for broadening the application of bioassay-coupled LC-QTOF MS/MS in natural product research.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.22 no.1
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• pp.1-8
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• 2022

Long-chain fatty acid oxidation disorders (LC-FAOD) are an autosomal recessive inherited rare disease group that result in an acute metabolic crisis and chronic energy deficiency owing to the deficiency in an enzyme that converts long-chain fatty acids into energy. LC-FAOD includes carnitine palmitoyltransferase type 1 (CPT1), carnitine-acylcarnitine translocase (CACT), carnitine palmitoyltransferase type 2 (CPT2), very long-chain acyl-CoA dehydrogenase (VLCAD), long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD), and trifunctional protein (TFP) deficiencies. Common symptoms of LC-FAOD are hypoketotic hypoglycemia, cardiomyopathy, and myopathy. Depending on symptom onset, the disease can be divided as neonatal period, late infancy and early childhood, adolescence, or adult onset, but symptoms can appear at any time. The neonatal screening test (NBS) can be used to identify the characteristic plasma acylcarnitine profiles for each disease and confirmed by deficient enzyme analysis or molecular testing. Before introduction of NBS, the mortality rate of LC-FAOD was very high. With NBS implementation as routine neonatal care, the mortality rate was dramatically decreased, but severe symptoms such as rhabdomyolysis recur frequently and affect the quality of life. Triheptanoin (Dojolvi^®), the first drug for pediatric and adult patients with molecularly confirmed LC-FAOD, has recently been approved by the US Food and Drug Administration in 2020. In this review, the diagnosis of LC-FAOD and treatment including triheptanoin are summarized.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.83-89
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• 2000

The purposes of this study were to evaluate clinical applicability of resin modified glass ionomer cements and to determine the effect of salivary contamination on the tensile bond strength. Fourty extracted human permanent premolars were prepared lot bonding and standard edgewise brackets were bonded with Ortho-One, Fuji Ortho LC, Vitremer and Advance. Fourty extracted human permanent premolars were contaminated with saliva, dried and bonded with same materials above. The tensile bond strength was tested by Instron testing device aster storage in normal saline at ,$37^{\circ}C$ for 24 hours from bonding. The results were as follows : 1. The tensile bond strength of Ortho-One group was $7.68\pm1.76$, Advance group was $7.87\pm2.80$, Fuji Ortho LC group was $4.99\pm2.53$, Vitremer group was $2.80\pm0.88$ MPa. The tensile bond strength in contaminated condition of Ortho-One group was $4.12\pm1.67$, Advance group was $5.37\pm0.68$, Fuji Ortho LC group was $4.41\pm1.61$, Vitremer group was $2.60\pm1.10$ Mpa. 2. Salivary contamination did not affect the tensile bond strength when compared with the uncontaminated enamel group in Fuji Ortho LC and Vitremer (p>0.05) and there was great significant difference in the tensile bond strength of Ortho-One and Advance. 3. Advance, Ortho-One and Fuji Ortho LC seemed to have clinically a proper bond strength.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.56-62
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• 2000

Effects of sublethal dose of imidacloprid on biological characteristics, such as longevity, fecundity and excretions from brown planthopper (BPH) and its repellency to imidacloprid were examined. Topical application of imidacloprid to BPH at the dose of $LD_{10}$ and $LD_{30}$ (These values were determined at 48 hours after topical application of imidacloprid) was remarkably increased the mortality from 3 days after application and showed over 90% mortality on 4 days after application. Topical application of imidacloprid at dose of $LD_{10}$ (16 days) showed no difference compared to the control (16.9 days) in the longevity, while application of $LD_{30}$ was reduced the longevity of BPH to 13.5 days. Application of sublethal dose of imidacloprid to BPH adults reduced the number of eggs laid per day and for adult stage, and the hatchability of their eggs. By root zone application at the dose of $LC_{30}$, 50% longevity and 40% fecundity was reduced respectively, but showed no effect on number of eggs laid per day. The day on which BPH laid 50 % of eggs in number were 7.6 days at the $LC_{10}$ and 5.9 days the of $LC_{30}$ respectively. Hatchabilities of the groups treated with imidacloprid were lower than that of the control. Topical application to BPH at the dose of $LD_{10}$ did not reduce the amount of excretes, but application at the dose of $LD_{30}$ was reduced 26.5% of excretion compared to the control. Leaf dipping into the solution of concentration of $LC_{10}$ and $LC_{30}$ was reduced 96.4% and 98.0% of excretion, respectively. And root zone treatment at the concentration of $LC_{10}$ and $LC_{30}$ reduced 79.5% and 96.6% of excretion, respectively. Repellency rates of BPH to imidacloprid were 20% regardless of the dose of application.