• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2000.10a
• /
• pp.118-124
• /
• 2000

Zn-resistant Methylosobacterium strains were isolated from several non-polluted soil samples collected in all over Japan. Zn-resistant Methylosobacterium strains were predominantly detected in all soil samples and they were also characterized as a UV-tolerant bacteria. The MIC test revealed that the isolates have high zinc resistance in comparison with that of reference Methylosobacterium strains obtained from culture collections. The 16S rDNA-based phylogenetic analysis showed that all strains were divided into two clusters designated as cluster A and cluster B in the present study. All isolates were distributed only in the cluster A. The phylogenetic clustering also well coincided with the differences in the pattern of carbon source utilization.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.20 no.5
• /
• pp.464-470
• /
• 2015

In this paper, a non-isolated three-level high step-up boost converter with output voltage balancing is proposed. By adding one extra inductor to the conventional three-level boost converter, the proposed converter is derived. Compared with the traditional boost converter and the three-level boost converter, the proposed converter can obtain very high voltage conversion ratio, and the voltage and current stress of switching devices and diodes are reduced. A 2.7 kW prototype converter is built and tested to verify performances of the proposed converter.

• Publications of The Korean Astronomical Society
• /
• v.30 no.2
• /
• pp.583-584
• /
• 2015

In this paper, the numerical results concerning different orbits of a 3D axisymmetric non-rotating galactic potential are presented. We use $Paczy{\acute{n}}ski^{\prime}s$ gravitational potential with different birth velocity distributions for the isolated old Neutron Star (NS) population. We note some smooth non-constant segments corresponding to regular orbits as well as the characterization of their chaoticity. This is strongly related to the effect of different kick velocities due to supernovae mass-loss and natal kicks to the newly-formed NS. We further confirm that the dynamical motion of the isolated old NSs in the gravitational field becomes obvious, with some significant diffraction in the symmetry of their orbital characteristics.

• Journal of Power Electronics
• /
• v.14 no.4
• /
• pp.649-660
• /
• 2014

A novel non-isolated bidirectional soft-switching SEPIC/ZETA converter with reduced ripple currents is proposed and characterized in this study. Two auxiliary switches and an inductor are added to the original bidirectional SEPIC/ZETA components to form a new direct power delivery path between input and output. The proposed converter can be operated in the forward SEPIC and reverse ZETA modes with reduced ripple currents and increased voltage gains attributed to the optimized selection of duty ratios. All switches in the proposed converter can be operated at zero-current-switching turn-on and/or turn-off through soft current commutation. Therefore, the switching and conduction losses of the proposed converter are considerably reduced compared with those of conventional bidirectional SEPIC/ZETA converters. The operation principles and characteristics of the proposed converter are analyzed in detail and verified by the simulation and experimental results.

• Journal of Power Electronics
• /
• v.15 no.4
• /
• pp.920-928
• /
• 2015

Transformerless solar inverters have a higher efficiency than those with an isolation link. However, they suffer from a leakage current issue. This paper proposes a family of single phase six-switch transformerless inverter topologies with an ac bypass circuit to solve the leakage current problem. These circuits embed two unidirectional freewheeling current units into the midpoint of a full bridge inverter, to obtain a freewheeling current path, which separates the solar panel from the grid in the freewheeling state. The freewheeling current path contains significantly fewer devices and poor performance body diodes are not involved, leading to a higher efficiency. Meanwhile, it is not necessary to add a voltage balancing control method when compared with the half bridge inverter. Simulation and experiments are provided to validate the proposed topologies.

• Journal of Power Electronics
• /
• v.15 no.2
• /
• pp.319-326
• /
• 2015

In this paper, a cost-effective single switch multi-channel LED (light emitting diode) driver is proposed. While conventional LED drivers require as many non-isolated DC/DC converters as the number of LED channels, the proposed LED driver needs only one power switch and several balancing capacitors instead of expensive non-isolated DC/DC converters. Therefore, the proposed driver features a simpler structure, with a lower cost and a higher efficiency. Because its power switch can be turned off under the zero current switching condition, it has very desirable advantages such as improved electromagnetic interference characteristics and high efficiency. Moreover, it uses only a small number of DC blocking capacitors with no additional active devices for the current balancing of multi-channel LEDs. As a result, the proposed driver exhibits high reliability and is cost effective. To confirm the validity of the proposed driver, a theoretical analysis is performed, and design considerations and experimental results obtained from a prototype that is applicable to a 46" LED-TV are presented.

• Journal of Yeungnam Medical Science
• /
• v.26 no.1
• /
• pp.78-83
• /
• 2009

Fibromuscular dysplasiais an uncommon condition of idiopathic, non-inflammatory and non-atherosclerotic disease of the musculature of arterial walls. The disease is rare, but it commonly affects young and middle aged women. Isolated intracranial cerebral fibromuscular dysplasia is extremely rare because cerebral fibromuscular dysplasia usually affects extracranial vessels. A 20-year-old woman was admitted with light hemiplegia and global aphasia. Brain MRI and MRA demonstrated acute left middle cerebral artery territory infarction with a multifocal stenosis and dilatation of the left middle cerebra artery and left internal carotid. The characteristic conventional cerebral angiographic findings demonstrated a typical string-of-beads appearance in the left distal internal carotid artery and proxiaml portion of the left middle cerebral artery, which suggested a medial type fibromuscular dysplasia. We report a case of isolated intracranial fibromuscular dysplasia with left middle cerebral artery territory infarction. Fibromuscular dysplasia should he considered as a stroke risk factors in children and young adults, especially in patients with no known cardiovascular risk factors.

• Journal of Chest Surgery
• /
• v.54 no.5
• /
• pp.429-432
• /
• 2021

Isolated iliac artery aneurysm (IAA) is rare, but can be fatal. Emergency surgery is performed in cases of hemorrhagic shock due to a suddenly ruptured IAA, which may have a high mortality rate because of massive non-compressible torso hemorrhage (NCTH). Recently, resuscitative endovascular balloon occlusion of the aorta (REBOA) has been accepted as an alternative to aortic cross-clamping via open thoracotomy to achieve hemostasis in trauma patients with profound shock due to NCTH and is considered an emerging bridging therapy for damage control. However, there is limited information on the use of REBOA in non-trauma patients with shock. Herein, we describe a patient with impending cardiac arrest due to isolated ruptured IAA, in whom perioperative bleeding was successfully controlled by REBOA.

• Journal of IKEEE
• /
• v.23 no.1
• /
• pp.273-279
• /
• 2019

A high boost dc-dc converter based on the switched-inductor cell (SL-cell) is suggested in this paper. The suggested converter can provide a high voltage gain that is more than 6. Moreover, the voltage gain can be easily increased by extending a SL cell or a modular voltage boost stage. This paper shows the key waveforms, the operating principles at the continuous conduction mode (CCM), and a comparison between the suggested converter and the other non-isolated converters. In addition, the extension of the suggested converter is presented. The simulation results were shown to reconfirm the theoretical analysis.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2003.03a
• /
• pp.93-100
• /
• 2003

Seismic isolation systems can improve the seismic safety of nuclear power plants by decreasing seismic force transmitted to structures and equipment. This study evaluates the effectiveness of equipment seismic isolation systems by the comparison of core damage frequencies in non-isolated and isolated cases. It can be found that the seismic isolation systems increase seismic capacity of nuclear equipment and decrease core damage frequencies significantly. The effect of equipment isolation is more significant in the PGA range of 0.3g to 0.5g.