• Title/Summary/Keyword: Resonance structures

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The Recent Study on Pain Modulation of Acupuncture (침의 통증 조절에 관한 최근 연구 동향)

  • Kim, Jong-Yoon;Koh, Hyeong-Gyun;Nam, Sang-Soo
    • Journal of Acupuncture Research
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    • v.23 no.1
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    • pp.145-154
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    • 2006
  • Objectives : To research the recent trends of study related to pain modulation of acupuncture. Methods : We searched the resent study related to pain modulation of acupuncture. Results & Conclusion : 1) Early studies demonstrated that the analgesic effects of acupuncture are mediated by opioid peptides in the periaqueductal gray. Recent evidences show that nitric oxide plays an important role in mediating the cardiovascular responses to acupuncture stimulation through gracile nucleus-thalamic pathway. 2) Recent evidences show that acupuncture stimulate gene expression related to pain. 3) By using functional magnetic resonance and positron emission tomography, recent study suggest that acupuncture has regionally specific, quantifiable effects on pain-relevant brain structures.

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A Highly Integrated HBT Downconverter MMIC for Application to One-chip RF tranceiver solution (One-chip 고주파 단말기에의 응용을 위한 고집적 HBT 다운컨버터 MMIC)

  • Yun, Young
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.6
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    • pp.777-783
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    • 2007
  • In this work, a highly integrated downconverter MMIC employing HBT(heterojunction bipolar transistor) was developed for application to one chip tranceiver solution of Ku-band commercial wireless communication system. The downconverter MMIC (monolithic microwave integrated circuit) includes mixer filter. amplifier and input/output matching circuit. Especially, spiral inductor structures employing SiN film were used for a suppression of LO and its second harmonic leakage signals. Concretely, they were properly designed so that the self-resonance frequency was accurately tuned to LO and its second harmonic frequency, and they were integrated on the downconverter MMIC.

Investigation of the Vortex Shedding with the Spring Mounted Circular Cylinder (스프링장착 원통형 실린더를 이용한 와류발산현상 파악)

  • Lee, Sang-Ho
    • The Journal of the Korea Contents Association
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    • v.10 no.11
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    • pp.446-451
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    • 2010
  • To investigate the vortex induced vibrations the 2-d.o.f. spring mounted circular cylinder was tested in the wind tunnel. The circular cylinder was designed to have the translational and the rotational mode uncoupled to each other. During the wind tunnel tests the resonance behaviors of the translational and the rotational modes by the locking-on phenomena were observed. From the locking-on phenomena observed it is shown that the vortex shedding is correlated with the responses of the structures. And the forces generated by the vortex shedding are influenced by the amplitudes and the frequencies of the cylinders.

Characterization of the molten globule conformation of V26A ubiquitin by far-UV circular dichroic spectroscopy and amide hydrogen/deuterium exchange

  • Park, Soon-Ho
    • BMB Reports
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    • v.41 no.1
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    • pp.35-40
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    • 2008
  • The molten globular conformation of V26A ubiquitin (valine to alanine mutation at residue 26) was studied by nuclear magnetic resonance spectroscopy in conjunction with amide hydrogen/deuterium exchange. Most of the amide protons that are involved in the native secondary structures were observed to be protected in the molten globule state with the protection factors from 1.2 to 6.7. These protection factors are about 2 to 6 orders of magnitude smaller than those of the native state. These observations indicate that V26A molten globule has native-like backbone structure with marginal stability. The comparison of amide protection factors of V26A ubiquitin molten globule state with those of initial collapsed state of the wild type ubiquitin suggests that V26A ubiquitin molten globule state is located close to unfolded state in the folding reaction coordinate. It is considered that V26A ubiquitin molten globule is useful model to study early events in protein folding reaction.

Non-linear Phenomenon in the Response of Circle Cantilever Beam (원형 외팔보의 응답에서의 비선형 현상)

  • Kim, Myung-Gu;Lee, Heung-Shik;Cho, Chong-Du
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.4 s.97
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    • pp.445-451
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    • 2005
  • This paper is the result of a experimental study about non-linear one to one modal coupling of a flexible circular cantilever beam which was transversely excited with harmonic excitation. It was proved that 2 order jumping in out of plane was caused by jump phenomenon in in-plane of flexible circular cantilever beam, because of non-linear coupling. In addition, cantilever beam showed hardening spring characteristics in in-plane and softening spring characteristics in out-of-plane.

Long lived spiral structures in galaxies

  • Saha, Kanak
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.1
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    • pp.31.1-31.1
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    • 2017
  • Spiral structure in disk galaxies is modeled with ncollisionless N-body simulations including live disks, halos, and bulges with a range of masses. Two of these simulations make long-lasting and strong two-arm spiral wave modes that last for about 5 Gyr with constant pattern speed. These two had a light stellar disk and the largest values of the Toomre Q parameter in the inner region at the time the spirals formed, suggesting the presence of a Q-barrier to wave propagation resulting from the bulge. The relative bulge mass in these cases is about 10%. Models with weak two-arm spirals had pattern speeds that followed the radial dependence of the Inner Lindblad Resonance. In addition to these, we also report a few more cases where two-armed spirals are developed and are maintained for a several rotation time scales.

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Properties of Interlayer Low Dielectric Polyimide during Aluminum Etching with Electron Cyclotron Resonance Etcher System

  • Kim, Sang-Hoon;Ahn, Jin-Ho
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2000.04a
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    • pp.87-96
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    • 2000
  • The properties of polyimide for interlayer dielectric applications are investigated during plasma etching of aluminum on it. Chlorine-based plasma generally used for aluminum etching results in an increase in the (dielectric constant of polyimide, while $SF_6$ plasma exhibits a high polyimide etch rate and a reducing effect of the dielectric constant. The leakage current of polyimide is significantly suppressed after plasma exposure. An optimal combination of Al etch with $Cl_6$ plasma and polyimide etch with $SF_6$ plasma is expected to be a good tool for realizing multilevel metallization structures.

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RFID Antenna using Fractal structure (프랙탈 구조를 이용한 RFID 안테나)

  • Kim, Ki-Chan;Ko, Young-Ho
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1389-1390
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    • 2008
  • In this paper, a This paper presents the Hilbert curve Fractal Antenna has properties of Self-similarity and Plane-Filling. In case of fractal antenna is very useful to be small and multiple resonant. The antenna has a resonant frequency of 910MHz and 2450MHz base on RFID(Radio Frequency IDentification). In particular, we designed tag antenna by the $4^{th}$ repeat. According to the repeated number of fractal structures, resonance frequency became looking downward. Theses presented Frequency, Such as 910MHz and 2450MHz, at $S_{11}$ is -31dB and -19dB, bandwidth 120MHz and 90MHz to VSWR 2:1.

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A new broadband energy harvester using propped cantilever beam with variable overhang

  • Usharani, R.;Uma, G.;Umapathy, M.;Choi, S.B.
    • Smart Structures and Systems
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    • v.19 no.5
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    • pp.567-576
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    • 2017
  • Design of piezoelectric energy harvester for a wide operating frequency range is a challenging problem and is currently being investigated by many researchers. Widening the operating frequency is required, as the energy is harvested from ambient source of vibration which consists of spectrum of frequency. This paper presents a new technique to increase the operating frequency range which is achieved by designing a harvester featured by a propped cantilever beam with variable over hang length. The proposed piezoelectric energy harvester is modeled analytically using Euler Bernoulli beam theory and the effectiveness of the harvester is demonstrated through experimentation. The results from analytical model and from experimentation reveal that the proposed energy harvester generates an open circuit output voltage ranging from 36.43 V to 11.94 V for the frequency range of 27.24 Hz to 48.47 Hz. The proposed harvester produces continuously varying output voltage and power in the broadened operating frequency range.

A Case of Thoracic Vertebral Chondroblastoma, Treated with 3-D Image Guided Resection and Reconstruction

  • Lee, Yoon-Ho;Shin, Dong-Ah;Kim, Keung-Nyun;Yoon, Do-Heum
    • Journal of Korean Neurosurgical Society
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    • v.37 no.2
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    • pp.154-156
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    • 2005
  • We present a case of chondroblastoma in the thoracic vertebra. A 40-year-old patient with upper back pain and lower extremity weakness was admitted to our clinic. On neurological examination, the patient exhibited lower extremity spastic paraparesis. Magnetic resonance imaging revealed a mass infiltrating the 7th thoracic vertebra and its adjacent structures with concomitant compression of the epidural space. After right upper lung tuberculoma was resected through the transthoracic approach, T7 total corpectomy was done with anterior stabilization using a MESH cage and T7 rib bone graft. Two weeks after the first operation, remained part of vertebra was removed and posterior stabilization was performed using a pedicle screw fixation and cross linkage bar with the assistance of the navigation system. The final pathologic diagnosis of the vertebral lesion was benign chondroblastoma.