• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.689-692
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• 2003

본 논문에서는 개방된 양 끝이 Loading 캐패시턴스로 연결된 새로운 행태의 1/2 파장 공진기를 이용해서 3단 대역통과 여파기를 설계, 제작하였다. 제안한 공진기의 전파지연효과(Slow-Wave Effect)때문에, 넓은 상향저지대역을 갖으며, 사이즈(Size)가 축소된 협대역 여파기 설계가 가능하다. 설계한 대역통과 여파기는 미세라인 구현이 가능한 후막 리소그라피 공정 기술을 이용하여 제작하였다.

• ETRI Journal
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• v.29 no.4
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• pp.533-535
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• 2007

For the purpose of decreasing intermodulation distortion, a new multi-harmonic suppression band-pass filter based on a microstrip radial stub is studied. Compared with traditional resonator filters, the new filter can suppress the second, third, and even fourth harmonics directly. The dimension of the filter is about $0.3\;{\lambda}_{g^0}{\times}0.13\;{\lambda}_{g^0}$ (${\lambda}_{g^0}$ is the guiding wavelength at the resonant frequency). Only one gap was introduced, so lower insertion loss can be obtained. Basic agreement between the measured and simulated results has been achieved.

• Advances in nano research
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• v.1 no.1
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• pp.13-27
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• 2013

Carbon nanotube characterized by additional inductive effect as compared with the traditional conductors like copper wires of the same size. Consequently, carbon nanotubes have high characteristic impedance and slow wave propagation in comparison with traditional conductors. Due to these characteristics, carbon nanotubes can be used as antenna. In view of this, we describe and review the present research progress on carbon nanotube antennas. We present different analysis models and results which are developed to investigate the characteristics of CNT antennas. Then we conclude by summarizing the characteristics of CNT antennas and specifying the operating frequency limit.

• Sleep Medicine and Psychophysiology
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• v.12 no.2
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• pp.87-92
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• 2005

Cytokines are the main regulatory molecules of not only immune system but also sleep system. Research on the role of cytokines on sleep has greatly been expanding since the first report of sleep-promoting effects of interleukin-1, the first cytokine molecule. Interleukin-1 and tumor necrosis factor are most widely studied among various cytokines. Studies over about twenty years demonstrate that most cytokines promote sleep but several cytokines inhibit sleep. Slow wave sleep is the main part that cytokines have effects on. Besides normal sleep physiology, cytokines have more major roles on pathophysiology of various sleep disorders. Obstructive sleep apnea is the representative sleep disorder that shows how deeply cytokines are involved in their pathophysiologic mechanisms of sleep disorders. Though there are many controversial issues on this topic, more mysterious part of normal sleep physiology and sleep disorders will be revealed in near future through thorough studies on sleep and cytokine.

• Sleep Medicine and Psychophysiology
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• v.2 no.1
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• pp.91-96
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• 1995

A 24-year-old woman complained of recurrent episodes of hypersomnia lasting on the average about 15 days with mild mood alternation such as depression and irritability. During interepisode interval, she was free of any symptoms. Depending on the absence of excessive eating and hypersexuality, she was clinically diagnosed as recurrent monosymptomatic hypersomnia or the incomplete form of Kleine-Levin syndrome. When nocturnal polysomnography and multiple sleep latency test were performed 10 days after her recovery from a hypersomnic episode, reduced slow wave sleep % and pathologic daytime sleepiness were still noted. The authors suggest that the clinical recovery in recurrent monosymptomatic hypersomnia precede electrophysiological normalization by several days.

• Sleep Medicine and Psychophysiology
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• v.3 no.1
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• pp.79-84
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• 1996

Kleine-Levin syndrome is a disorder characterized by recurrent episodes of hypersomnia, hyperphagia and hypersexuality that typically occur weeks or months apart. A 17-years-old male showed these episodes and took nocturnal polysomnography(NPSG) and multiple sleep latency test(MSLT). As results of NPSG, sleep latency was 82.5min, sleep efficiency was 82.5min, sleep efficiency was 82.5%, latency and percentage of REM sleep were 106.5min and 14.6% and percentage of slow wave sleep was 12.7%. In 4 times MLST, average of sleep latency and REM latency were 8min 7sec and 5min 20sec with 3 times sleep onset REM period(SOREMP). These findings are consistent with these of Keine-Levin syndrome. And the possible causes and classification of this syndrome were discussed.

• Sleep Medicine and Psychophysiology
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• v.18 no.2
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• pp.67-71
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• 2011

Schizophrenia is a chronic, currently incurable, and devastating syndrome. Although sleep disturbances are not primary symptoms of schizophrenia, they are important aspects of schizophrenia. Difficulties initiating or maintaining sleep are frequently encountered in patients with schizophrenia. Many schizophrenics report low subjective sleep quality. Measured by polysomnography, increased sleep latency as well as reduced total sleep time, sleep efficiency, slow wave sleep, and rapid eye movement sleep latency (REM latency), are found in most patients with schizophrenia and appear to be an important aspect of the pathophysiology of this disorder. Some literatures suggest that worsening sleep quality precedes schizophrenic exacerbations. Co-morbid sleep disorders such as obstructive sleep apnea (OSA) and restless legs syndrome (RLS), and sleep-disrupting behaviors associated with schizophrenia may lead to sleep disturbances. Clinicians should screen the patient with sleep complaints for primary sleep disorders like OSA and RLS, and carefully evaluate sleep hygiene behaviors of all patients with schizophrenia who complain of sleep disturbances.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.273-276
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• 2003

본 논문에서는 한쪽이 단락된 스트립선로(Stripline)와 Loading 캐패시턴스(Capacitance)로 구성된 새로운 형태의 1/4파장 스트립선로 공진기를 제안하였으며, 이 공진기를 이용해서 5.2 GHz 대역 무선 LAN용 적층 대역통과 여파기를 설계, 제작 하였다. 제안한 공진기의 전파지연효과(Slow-wave Effect) 때문에, 기존의 공진기에 비해서 길이가 축소되며, 기준 공진주파수(Fundamental Resonant Frequency)에 대한, 첫 번째 기생공진주파수(First Spurious Resonant Frequency) 값이 커지기 때문에, 넓은 상향저지대역(Wide Upper Stopband)을 갖는 초소형의 대역통과 여파기의 설계가 가능하다. 설계한 여파기를 LTCC 적층 공정 기술을 이용하여 제작하였으며 그 크기는 $3.2mm{\times}1.6mm{\times}0.8mm$ 이다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.63-66
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• 2009

Lighting currents are one of major influences on the dynamic performance of ground electrodes. High lighting current intensity changes in the dynamic grounding performance due to ionization of the soil and very fast fronted pulses. The previous analysis has often been based on quasi-static approximation that is not applicable to very fast fronted pulses. To extend the analysis to fast fronted pulses in this paper, the full-wave analysis method based in the rigorous electromagnetic-field theory approach is used and the effects of the ionization of the soil me disregarded. Based on the simulation results, the empirical formulas applicable for slow and very fast fronted lightning current pulses me reviewed; therefore the validity of the theoretical approach is verified through comparison between the calculated and measured results.

• Advances in nano research
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• v.12 no.4
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• pp.345-352
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• 2022

In this paper, natural frequency curves are presented for three specific end supports considering distinct values of nonlocal parameter. The vibrational behavior of zigzag double walled carbon nanotubes is investigated using wave propagation with nonlocal effect. Frequency spectra of zigzag (12, 0) double walled carbon nanotubes have been analyzed with proposed model. Effects of nonlocal parameters have been fully investigated on the natural frequency against against variation of Poisson's ratio. A slow increase in frequencies against variation of Poisson's ratio also indicates insensitivity of it for suggested nonlocal model. Moreover, decrease in frequencies with increase in nonlocal parameter authenticates the applicability of nonlocal Love shell model. Also the frequency curves for C-F are lower throughout the computation than that of C-C curves.