• Journal of Power Electronics
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• v.15 no.6
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• pp.1654-1663
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• 2015

Compared to LC resonance, LCL resonance has distinct advantages such as a large resonant capability, low voltage and current stresses of the power device, constant voltage or current output characteristics, and fault-tolerance capability. Thus, LCL resonant compensation is employed for a movable Inductive Contactless Power Transfer (ICPT) system with a multi-load in this paper, which achieves constant current output characteristics. Peculiarly, the primary side adopts a much larger compensation inductor than the primary leakage inductor to lower the reactive power, reduce the input current ripple, generate a large current in the primary side, and realize soft-switching. Furthermore, this paper proposes an approximate resonant point for large inductor-ratio LCL resonant compensation through fundamental wave analysis. In addition, the PWM control strategy is used for this system to achieve constant current output characteristics. Finally, an experimental platform is built, whose secondary E-Type coils can ride and move on a primary rail. Simulations and experiments are conducted to verify the effectiveness and accuracy of both the theory and the design method.

• Journal of the Korean Magnetic Resonance Society
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• v.2 no.1
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• pp.41-49
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• 1998

A linear undecapeptide, Substance P (SP) is involved in a wide variety of physiological processes such as pain, inflammation, salivation, and hypertension. Tertiary structure of SP in dodecylphosphocholine (DPC) micelles has been investigated by CD, NMR spectroscopy, and DGII calculation. CD spectrum of SP in the presence of 7.5 mM DPC micelles does not show any favorable secondary structure. The tertiary structure determined by NMR spectroscopy and DGII calculation shows that the Phe7-Phr8-Gly9-Leu10 region adopts a turn structure, while the N-terminal region is quite flexible. Both prolines in SP exist preferentially as the trans isoforms and the aromatic ring of Phe7 protrudes outward. Conformation of SP may be restrained by the contact of the Phe7 aromatic ring with the hydrophobic side chains of the DPC micelles and this interaction induces a turn structure. Structure of SP in aqueous solution in the presence of DPC micelles can represent a good model to study the conformation recognized by the receptor near neutral membrane.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.3
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• pp.80-85
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• 2008

Capsule endoscopes generally use primary cells as a power source due to its limited space. However, the primary cells have several limitations such as high cost, limited power and no reuse. To solve these problems, a new wireless energy transmission method is proposed. The proposed approach uses air-gap transformer concepts and LC resonance to transmit energy from transmitter(primary side) to capsule endoscopes(secondary side). The ferrite core with 3-axis winding is used to increase energy transfer efficiency regardless of direction and location. The experimental results show that the proposed method stably supplies 30mW power to secondary circuit.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.5
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• pp.431-440
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• 2021

Background: Neurovascular compression (NVC) is a well-known cause of trigeminal neuralgia (TN). However, patients with idiopathic TN (ITN) do not have evidence of NVC on magnetic resonance imaging (MRI), and other patients may remain asymptomatic despite evidence of NVC on MRI. This suggests that there may be additional risk factors for TN development other than NVC. Although epidemiological factors, such as age and sex differences, are useful for understanding the pathophysiology of TN, detailed statistics for each TN subtype are currently unavailable. Therefore, this study aimed to classify patients with TN into the following groups based on data extracted from past medical records: classical TN (CTN), secondary TN, and ITN. Methods: The characteristics of the groups and their differences were explored. Results: CTN was more common in women than in men, as previously reported, whereas ITN was more common in men than in women. The ratio of pain sites located on the right side of the face was high in all groups. Patients with CTN were also prone to NVC on the asymptomatic side. Conclusion: By investigating TN subtype, it may be possible to elucidate the pathophysiology of TN. This would greatly improve treatment outcomes.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.2
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• pp.153-160
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• 2013

This research paper describes the development of battery charger with a variable output voltage capacity for charging the batteries used in electrical vehicles. The voltage and current accordingly is control via the buck converter that receives three phase current at primary side and fed to bridge rectifier which is comprised of full bridge converter and HFTR(High Frequency Transformer) for isolation and a square wave AC output. The transformer primary side is in series to divide certain charging current and the secondary side is comprised of six fix transformers so that they can generate certain amount of power and various output voltage through relay connection using 6 DC outputs. Moreover, all parallel connected full bridge serial resonant converter communicate together with upper(main) controller. The constructed structure is verified by conducting the test on PSIM as well as experimentally.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.4
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• pp.337-346
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• 2014

This study aimed to understand the mode characteristics of a droplet subject to periodic forced vibration and the detachment of a droplet placed on a plate surface. An surface was coated with Teflon to clearly observe the behavior of a droplet. The contact angle between the droplet and surface and the hysteresis were found to be approximately $115^{\circ}C$ and within $25^{\circ}C$, respectively. The coating process was performed in a clean room that had an environment with a low level of contaminants and impurities such as air dust, detergents, and particles. To predict the resonance frequency of a droplet, theoretical and experimental approaches were applied. Two high-speed cameras were configured to acquire side and top views and thus capture different characteristics of a droplet: the mode shape, the detachment, the separated secondary droplet, and the waggling motion. A comparison of the theoretical and experimental results shows no more than 18 discrepancies when predicting the resonance frequency. These differences seem to be caused by contact line friction, nonlinear wall adhesion, and the uncertainty of the experiment. For lower energy inputs, the contact line of the droplet was pinned and the oscillation pattern was axisymmetric. However, the contact line of the droplet was de-pinned as the oscillation became more vigorous with increased energy input. The size of each lobe at the resonance frequency is somewhat larger than that at the neighboring frequency. A droplet in mode 2, one of the primary mode frequencies, exhibits vertical periodic movement as well as detachment and secondary ejection from the main droplet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.491-499
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• 2019

Recently, there has been increasing demand for power quality in power supply devices. The IEC 61000-3-2 standard requires that the AC / DC power supply for lighting meet the specifications for the power factor (PF) and total waveform distortion (THD). In addition, advanced countries in Europe are regulating the ripple rate as 15 ~ 30% for the flicker phenomenon caused by the change in the amount of foot energy due to the change in current of the output terminal. Therefore, domestic standards and regulations are being updated. This study adopted the Flyback converter to satisfy the PFC standard, and has the circuit first and second insulation function. To reduce the low frequency ripple of the LED current, Flyback, Coupled Inductor, LC parallel resonance filter, LLC resonance filter, and Cuk were simulated by PSIM to mimic each LED driving circuit. A coupled LC resonant circuit with a coupled inductor on the primary side and LC resonance on the secondary side was also proposed for output side ripple reduction.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.218-221
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• 2005

This report describes a case of dizziness in a patient with trigeminal neuralgia that was caused by a vestibular schwannoma. A 60-year-old man with a history of pain on his left cheek, chin, molar and tongue for 5 months was diagnosed as suffering with trigeminal neuralgia of the left mandibular nerve, and this was caused by a left vestibular schwannoma. The diagnosis of the tumor was confirmed with magnetic resonance imaging (MRI), and so gamma knife surgery was performed 1 month later. At that time, the patient had been referred to the pain clinic due to allodynia on the tongue and gingival, and hypesthesia was also present on the left half of the face. Trigeminal nerve block with dehydrogenated alcohol and stellate ganglion block with 1% mepivacaine were performed and oral medication with diphenylhydantoin was started. The symptoms were alleviated after nerve block and oral medication. Dizziness, blurred vision and ataxia then developed from the 13th hospital day. We considered the symptoms as a side effect of diphenylhydantoin and we reduced the dose of diphenylhydantoin. However, the symptoms grew worse. Another brain MRI showed a slight increase of the tumor size and a mass effect with displacement of the adjacent organs, and hydrocephalus was also noted. This case shows the importance of considering the secondary symptoms that are due to brain tumor while treating trigeminal neuralgia. The changes of the brain tumors should also be considered along with the presence of new side effects.

• Journal of Veterinary Clinics
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• v.27 no.2
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• pp.186-189
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• 2010

A 14-year-old neutered female Chihuahua was presented because of seizure episodes and circling to the left side. Based on neurological examination, the lesion was localized on left forebrain. The mass in the left nasal cavity and breaching of the nasal septum were seen magnetic resonance images. And there was a presence of contrast enhanced mass involving the rostral left brain. Based on diagnostic image analysis, this lesion strongly suggested secondary brain tumor infiltrated by nasal cavity. The patient's symptoms were well controlled by a combination therapy of prednisolone and lomustine (CCNU), and survived for two months after diagnosis. This case was definitively diagnosed as a nasal neuroendocrine carcinoma based on histopathological findings. This report describes the clinical findings, imaging characteristics, and pathologic features of secondary brain tumor which caused by infiltration of nasal neuroendocrine carcinoma in a dog.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.341-345
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• 2004

A high efficiency and low device stress voltage and current clamping BVS PWM asymmetrical half bridge converter is proposed in this paper. To achieve the ZVS of power switches along the wide load range, the transformer leakage inductor $L_{Ikg}$ is increased. Then, to solve the problem related to ringing in the secondary rectifier caused by the resonance between $L_{Ikg}$ and rectifier junction capacitors, the proposed converter employs a voltage and current clamping cell, which helps voltages and currents of rectifier diodes to be clamped at the output voltage and output current, respectively. Therefore, no RC-snubber for rectifier diodes is needed and a high efficiency as well as low noise output voltage can be realized. In addition, since all energy stored in $L_{Ikg}$ is transferred to the output side, the circulating energy problem can be effectively solved and duty loss does net exist. The operational principle, theoretical analysis, and design considerations are presented. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 425W, 385-170Vdc prototype are presented.