• Journal of Electrical Engineering and Technology
• /
• v.8 no.3
• /
• pp.507-515
• /
• 2013

This paper proposes a compensation method for the $2^{nd}$-order harmonic of single-phase grid-connected wind power generation systems. Theoretically, a single-phase grid-connected inverter system has no choice but to cause the $2^{nd}$-order harmonic to DC-link voltage. The reference active current is affected by the DC-link voltage. The output current from the reference active current is distorted by the $1^{st}$ and $3^{rd}$-order harmonic. The proposed method can compensate, conveniently, the reference active current with the $2^{nd}$-order harmonic. To reduce the $2^{nd}$-order ripple in the reference active current, proposed method takes a PR controller as a feed-forward compensator. PR controllers can implement selective harmonic compensation without excessive computational requirements; the use of these controllers simplifies the method. Both the simulation and experimental results agree well with the theoretical analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2000.10a
• /
• pp.207-211
• /
• 2000

The mobile communication technology which provides various data service and satifies the required quality in wireless environment can be classified as the forth generation mobile communication technology the forth generation communication technology must has diference with the 2nd and 3nd generation mobile communication technology. It must has the more advanced and more united shape than 3nd generation mobile communication. The forth generation mobile communication technology include following technology: Adaptive coding ar modulation, Smart antenna, Interference cancellation, Advanced handoff mechanism between networks. In this study, I represent the development and standardization of this technology.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.6
• /
• pp.1141-1149
• /
• 2009

Pulse style Nd: YAG Laser is suitable in skin remaking treatment, in compliance with the ramp continuous oscillation until of course normal takeoff, the Q-switch and mode motive takeoff the takeoff form which is various is possible and it is coming to be widely used in microsurgery and skin remaking promotion. According to therapeutic objective very it is important to control a energy density. Control of energy density the method which controls the pulse repetition rate of Laser output is mainly used. From the research which it sees pulse style Nd: It will be able to control the pulse repetition rate of YAG, the 2nd harmonic occurrence Laser (second harmonic generation: SHG) with the energy part of the light-wave which is a footnote wave number will hold and nonlinear decision it propagates and is converted by energy of the light-wave which is a footnote wave number the actual condition which and it applies the second harmonic occurrence in compliance with a secondary nonlinearity it leads and until skin deep part therapeutic possibility is the thing it will be able to observe simply.

• Korean Journal of Agricultural Science
• /
• v.42 no.4
• /
• pp.305-311
• /
• 2015

In this research, we surveyed the yield change of garlic cultivation with seed bulbs according to annual field culture after induced meristem culture. From 2007 to 2013, yearly produced seed bulbs from $2^{nd}$ to $8^{th}$ generation were cultivated in the Muan field. Over the generations, the general growth characteristics such as the plant height, leaf number, leaf length and stem diameter were all decreased. When we compared the conventional seed bulbs and TCR ones, the plant height and stem diameter showed bigger difference. And the TCR seed bulbs showed a week late harvest time against the conventional ones. The yield of $2^{nd}$ generation was 72.3 g and 57.1 g for the $8^{th}$ generation. However every generation showed higher yield than conventional seed garlic's ones as 43.9 g. The yield index showed the same trend as $2^{nd}-8^{th}$ to 63% to 21%. After the tissue culture of garlics, the viral infections (OYDV and GSV) of TCR was far less than that of conventional ones. In case of LYSV, the infection ratio was 6.7% at $2^{nd}$ generation and 26% at $8^{th}$. However, the ratio was far less than that (80%) of the conventional ones.

• 전기의세계
• /
• v.53 no.10
• /
• pp.20-22
• /
• 2004

• Proceedings of the Optical Society of Korea Conference
• /
• 1998.08a
• /
• pp.72-73
• /
• 1998

• Journal of Electrical Engineering and Technology
• /
• v.8 no.2
• /
• pp.326-330
• /
• 2013

The Korea Superconducting Tokamak Advanced Research (KSTAR) device is an advanced superconducting tokamak to establish scientific and technological bases for attractive fusion reactor. This device requires 3.5 Tesla of toroidal field (TF) for plasma confinement, and requires a strong poloidal flux swing to generate an inductive voltage to produce and sustain the tokamak plasma. KSTAR was originally designed to have 16 serially connected TF magnets for which the nominal current rating is 35.2 kA. KSTAR also has 7 pairs of poloidal field (PF) coils that are driven to 1 MA/sec for generation of the tokamak plasma according to the operation scenarios. The KSTAR Magnet Power Supply (MPS) was dedicated to the superconducting (SC) coil commissioning and $2^{nd}$ plasma experiment as a part of the system commissioning. This paper will describe key features of KSTAR MPS for the $2^{nd}$ plasma experiment, and will also report the engineering and commissioning results of the magnet power supplies.

• Korean Circulation Journal
• /
• v.48 no.11
• /
• pp.989-999
• /
• 2018

Background and Objectives: We aimed to compare outcomes of complete revascularization (CR) versus culprit-only revascularization for ST-segment elevation myocardial infarction (STEMI) and multivessel disease (MVD) in the $2^{nd}$ generation drug-eluting stent (DES) era. Methods: From 2009 to 2014, patients with STEMI and MVD, who underwent primary percutaneous coronary intervention (PCI) using a $2^{nd}$ generation DES for culprit lesions were enrolled. CR was defined as PCI for a non-infarct-related artery during the index admission. Major adverse cardiovascular event (MACE) was defined as cardiovascular (CV) death, non-fatal myocardial infarction, target lesion revascularization, or heart failure during the follow-up year. Results: In total, 705 MVD patients were suitable for the analysis, of whom 286 (41%) underwent culprit-only PCI and 419 (59%) underwent CR during the index admission. The incidence of MACE was 11.5% in the CR group versus 18.5% in the culprit-only group (hazard ratio [HR], 0.56; 95% confidence interval [CI], 0.37-0.86; p<0.01; adjusted HR, 0.64; 95% CI, 0.40-0.99; p=0.04). The CR group revealed a significantly lower incidence of CV death (7.2% vs. 12.9%; HR, 0.51; 95% CI, 0.31-0.86; p=0.01 and adjusted HR, 0.57; 95% CI; 0.32-0.97; p=0.03, respectively). Conclusions: CR was associated with better outcomes including reductions in MACE and CV death at 1 year of follow-up compared with culprit-only PCI in the $2^{nd}$ generation DES era.

• Journal of Animal Science and Technology
• /
• v.51 no.2
• /
• pp.123-128
• /
• 2009

Recently, the $2^{nd}$ generation genome map of the Korean cattle (Hanwoo) has been constructed by comparison of the nucleotide sequence of the Korean cattle BAC clones with whole genome sequence of the bovine data-base (B_tau 2.1 build). The objective of this study was to update the $2^{nd}$ generation genome map of the Korean cattle using the similar approach. The nucleotide sequence of the Korean cattle BAC clones utilized in the construction of the $2^{nd}$ generation map was compared with the newly released bovine data-base (B_tau 3.1 build) to generate the $3^{rd}$ generation map. While, 5,105 BAC clones were localized on bovine chromosome in the $2^{nd}$ generation map, a total of 9,595 BAC clones, which spans about 37.27% of the bovine chromosome after eliminating the overlapping sequence among the clones, have been mapped on the bovine chromosome in the $3^{rd}$ generation map. Further analysis of the nucleotide sequence of the BAC clones will allow us to develop map and facilitate to pinpoint the genes that are important for the improvement of the performance in this cattle breed.

• International Journal of Oral Biology
• /
• v.34 no.4
• /
• pp.205-213
• /
• 2009

The mechanisms underlying the actions of the antioxidants upon reactive oxygen species (ROS) generation by NADPH oxidase complex have remained uncertain. In this study, we investigated NADPH oxidase activity and the role of antioxidant enzymes upon the generation of ROS during hypoxic stress. ROS generation was found to increase in the mouse kidney under hypoxic stress in a time-dependent manner. Moreover, we found in MCT cells that hypoxia-induced hydrogen peroxide production was decreased by NAC pretreatment. We further analyzed HIF-$1{\alpha}$, PHD2 and VHL expression in the NAC-pretreated MCT cells and assessed the response of antioxidant enzymes at the transcriptional and translational levels. SOD3 and Prdx2 were significantly increased during hypoxia in the mouse kidney. We also confirmed in hypoxic $Prdx2^{-/-}$ and SOD3 transgenic mice that erythropoietin (EPO) is transcriptionally regulated by HIF-$1{\alpha}$. In addition, although EPO protein was found to be expressed in a HIF-$1{\alpha}$ independent manner in three mouse lines, its activity differed markedly between normal and $Prdx2^{-/-}$/SOD3 transgenic mice during hypoxic stress. In conclusion, our current results indicate that NADPH oxidase-mediated ROS generation is associated with hypoxic stress in the mouse kidney and that SOD3 and Prdx2 cooperate to regulate cellular redox reactions during hypoxia.