• Bulletin of the Korean Mathematical Society
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• v.52 no.6
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• pp.1911-1924
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• 2015

A cyclotomic polynomial ${\Phi}_n(x)$ is said to be ternary if n = pqr for three distinct odd primes p < q < r. Let A(n) be the largest absolute value of the coefficients of ${\Phi}_n(x)$. If A(n) = 1 we say that ${\Phi}_n(x)$ is flat. In this paper, we classify all flat ternary cyclotomic polynomials ${\Phi}_{pqr}(x)$ in the case $q{\equiv}{\pm}1$ (mod p) and $4r{\equiv}{\pm}1$ (mod pq).

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.5
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• pp.435-441
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• 2003

Dynamic Voltage Restorers (DVR)s are known as the best effective and economic means to compensate for voltage sags and swells. This paper proposes a novel method to generate reference voltages synchronized with the grid whether the line voltages are distorted by a fault or not. The proposed reference wave generator (RWG) looks for the original wave forms from the corrupted line voltages and synthesizes the expected positive sequence reference waves for DVRs. There is no transient problem on the generated reference waves when the line voltages are distorted by the fault.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.38-39
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• 2003

The GaAs semiconductor whispering gallery modes, produced in the peripheral Rayleigh band region of W／sub Rayleigh／ ＝ (${\Phi}$／2)( 1-n／sub eff／n), exhibit novel properties of ultralow thresholds open to nano-ampere regime associated with photonic quantum ring (PQR) production (Fig 1 (a)). The PQR phenomena are associated with a photonic field-driven phase transition of quantum well(QW)-to-quantum wire (QWR) and hence the photonic (non-de Broglie) quantum corral effects, on the Rayleigh cavity confined carriers in dynamic steady state, occur as schematically shown in Fig 1. (omitted)

• Proceedings of the Korean Society of Grassland Science Conference
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• 2000.09a
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• pp.101.1-101
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• 2000

• 한국인삼전략화협의회:학술대회논문집
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• v.2003 no.09
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• pp.77-88
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• 2003

"Ginseng (Panax ginseng C.A. Meyer) has been a popular herbal remedy used in eastern Asian cultures for thousands of years, and a number of health claims are made for it. Modern therapeutic claims for ginseng refer to vitality, immune function, cancer, cardiovascular diseases, diabetes and sexual function. These claims are mostly based on uncontrolled or non-randomized studies. Among modern therapeutic claims, however, therapeutic effects for diabetes can reasonably be accepted. Following experiment was done recently in our lab: this study was designed to compare the antidiabetic activities between Ginseng Radix Alba (GRA), Ginseng Radix Rubra (GRR) and Panax Quinquefoli Radix (PQR) in multiple low dose (MLD) streptozotocin (STZ) (20mg/kg i.p injection for 5 days) induced diabetic rats. In the glucose tolerance test, 500mg/kg of each ginseng ethanol extract was admoinistered intraperitoneally 30min before glucose challenge. While GRA failed to lower blood glucose level, GRR and PQR both significantly prevented the hyperglycemia when compared with the control group. In the MLD STZ-induced diabetic rats, 300 mg/kg of each ginseng ethanol extract was administered intraperitoneally for 2 weeks. Plasma glucose and insulin levels were markedly improved in all treatment groups. While GRR showed the highest antidiabetic activity, and GRA and PQR revealed somewhat equipotent antidiabetic activities, but less than that in GRR-treated group as for as blood parameters and diabetic symptoms such as polydipsia are concerned. Blood glucose levels were closely associated with plasma insulin levels, and this result may suggest that ginseng ethanol extracts showed the activity to enhance insulin secretion as well as preventing destruction of pancreatic islet cells. To elucidate the relationship between antidiabetic activity and ginsenoside profiles, seven major ginsenoside were quantified by HPLC. We figured out the fact that protopanaxatriol (PPT) : proptopanaxadiol (PPD) ratio might play an important role in its hypoglycemia effects."

• Journal of Convergence for Information Technology
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• v.10 no.6
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• pp.28-34
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• 2020

A structure in which GaAs and AlGaAs epilayers are formed with a metal organic chemical vapor deposition equipment on a GaAs wafer similar to the structure of making a vertical cavity surface emitting laser is used. Photonic Quantum Ring (PQR) devices that are naturally generated by 3D resonance are manufactured by chemically assisted ion beam etching technology, which is a dry etching method. A new technology that can be fabricated has been studied, and as a result, the possibility of wet etching of a solution containing phosphoric acid, hydrogen peroxide and methanol was investigated, and the device fabrication by applying this method are also discussed. In addition, the spectrum of the fabricated optical device was measured, and the results were theoretically analyzed and compared with the wavelength value obtained by the measurement. It is expected that the PQR device will be able to model cells in a three-dimensional shape or be applied to the display field.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.5
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• pp.420-429
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• 2004

This paper proposes a novel current control strategy on active power filters using PQR instantaneous power theory which can compensate the line current harmonics and the neutral line current under the unbalanced and/or distorted source conditions in three-phase four-wire systems. The characteristics of the inverter ac filters are analyzed and a novel digital controller are proposed to overcome the inherent time delay problem in digital controllers with designed control gain in this paper. The proposed current control method is based on a sinusoidal PWM for fully-digital implementation compared with a conventional hysteresis PWM. PSiM simulation results verify the good performance of the proposed current control strategy on shunt type APFs.

• Journal of Ginseng Research
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• v.27 no.2
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• pp.56-61
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• 2003

This study was designed to compare the antidiabetic activities between Ginseng Radix Alba (GRA), Ginseng Radix Rubra (GRR) and Panax Quinquefoli Radix (PQR) in multiple low dose (MLD) streptozotocin (STZ) (20 mg/kg i.p injection far 5 days) induced diabetic rats. In the glucose tolerance test, 500 mg/kg of each ginseng ethanol extract was administered intraperitoneally 30 min before glucose challenge. While GRA failed to lower blood glucose level, GRR and PQR both significantly prevented the hyperglycemia when compared with the control group. In the MLD STZ-induced diabetic rats, 300 mg/kg of each ginseng ethanol extract was administered intraperitoneally for 2 weeks. Plasma glucose and insulin levels were markedly improved in all treatment groups. While GRR showed the highest antidiabetic activity, and GRA and PQR revealed somewhat equipotent antidiabetic activities, but less than that in GRR-treated group as far as blood parameters and diabetic symptoms such as polyphagia and polydipsia are concerned. Blood glucose levels were closely associated with plasma insulin levels, and this result may suggest that ginseng ethanol extracts showed the activity to enhance insulin secretion as well as preventing destruction of pancreatic islet cells. To elucidate the relationship between antidiabetic activity and ginsenoside profiles, seven major ginsenosides were quantified by HPLC. We figured out the fact that protopanaxatriol (PPT): proptopanaxadiol (PPD) ratio might play an important role in its hypoglycemia effects.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2002.09a
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• pp.19.2-20
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• 2002

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.308-309
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• 2004