• Title/Summary/Keyword: Self-resonance

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The fabrication of the embedded inductor in the PCB for high integration (고집적화를 위한 PCB에 내장된 인덕터의 제작)

  • Yun, Seok-Chul;Song, Il-Jong;Nam, Kuang-Woo;Sim, Dong-Ha;Song, In-Sang;Lee, Youn-Seoung;Kim, Hak-Sun
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.178-182
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    • 2003
  • This paper presents the embedded inductors in PCB (Printed Circuit Board) for PAM(Power Amplifier Module) of mobile terminations. The inductors are designed, simulated, and compared to conventional chip inductors. The Quality factor(Q) and self-resonance frequency(SRF) of the inductors are evaluated. The quality factors of the inductors are two times higher than those of the chip inductors, and the self-resonance frequency is 1.3 times higher than those of chip inductors at the inductance of 2.7 nH and 3.3 nH respectively.

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Characteristics of Wind Noise from Overhead Transmission Facilities (가공 송전설비의 소음 특성)

  • 추장희;김상범;신구용;이성두;이동일
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.465-472
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    • 2001
  • This paper describes the characteristics of wind induced noise from high-voltage overhead transmission facilities which include transmission lines. insulator strings. and aviation beacon spheres installed on the overhead ground wires. High-voltage overhead transmission lines generate an audible wind noise due to the alternate shedding of wind-induced vortices. The frequency spectrum from the insulator strings reveals its resonance peak. This resonance sound mechanism has been supposed the self-excitation phenomenon of the resonance and the velocity fluctuation. The booming noises from the aviation beacon spheres are detected and analysed.

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In Vitro Study on the Initial Stability of Two Tapered Dental Implant Systems in Poor Bone Quality (연질 골에서 두 종류의 테이퍼 형태 임플란트의 초기 안정성에 관한 실험실적 연구)

  • Kim, Duck-Rae;Kim, Myung-Joo;Kwon, Ho-Beom;Lee, Seok-Hyung;Lim, Young-Jun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.25 no.4
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    • pp.391-401
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    • 2009
  • The successful outcome of dental implants is mainly the result of intial implant stability following placement. The aim of this study was to investigate the effect of a self-tapping blades and implant design on initial stability of two tapered implant systems in poor bone quality. The two different implant systems included one with self-tapping blades and one without self-tapping blades. D4 bone model using Solid Rigid Polyurethane Form was used to simulate poor bone densities. The insertion torque during implant placement was recorded. Resonance frequency Analysis (RFA), measured as the implant stability quotient (ISQ), was assessed immediately after insertion. Finally, the implant-bone specimen was transferred to an Universal Testing Machine to measure the axial pull-out force. Insertion torque values and maximum pull-out torque value of the non self-tapping implants were significantly higher than those in the self-tapping group (P = 0.008). No statistically differences were noted between the two implant designs in RFA. Within the each implant system, no correlation among insertion torque, maximum pull-out torque and RFA value could be determined. Higher insertion torque of the non-self-tapping implants appeared to confirm higher clinical initial stability. In conclusion, implants without self-tapping blades have higher initial stability than implants with self-tapping blades in poor bone quality.

A study on dynamic modulus of self-consolidating rubberized concrete

  • Emiroglu, Mehmet;Yildiz, Servet;Kelestemur, M. Halidun
    • Computers and Concrete
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    • v.15 no.5
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    • pp.795-805
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    • 2015
  • In this study, dynamic modulus of elasticity of self-consolidating rubberized concrete is evaluated by using results of ultrasonic pulse velocity and resonance frequency tests. Additionally, correlation between dynamic modulus of elasticity and compressive strength results is compared. For evaluating the dynamic modulus of elasticity of self-consolidating rubberized concrete, prismatic specimens having $100{\times}100{\times}500$ mm dimensions are prepared. Dynamic modulus of elasticity values obtained by non-destructive measurements techniques are well agreed with those given in the literature.

Brain MR Multimodal Medical Image Registration Based on Image Segmentation and Symmetric Self-similarity

  • Yang, Zhenzhen;Kuang, Nan;Yang, Yongpeng;Kang, Bin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.3
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    • pp.1167-1187
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    • 2020
  • With the development of medical imaging technology, image registration has been widely used in the field of disease diagnosis. The registration between different modal images of brain magnetic resonance (MR) is particularly important for the diagnosis of brain diseases. However, previous registration methods don't take advantage of the prior knowledge of bilateral brain symmetry. Moreover, the difference in gray scale information of different modal images increases the difficulty of registration. In this paper, a multimodal medical image registration method based on image segmentation and symmetric self-similarity is proposed. This method uses modal independent self-similar information and modal consistency information to register images. More particularly, we propose two novel symmetric self-similarity constraint operators to constrain the segmented medical images and convert each modal medical image into a unified modal for multimodal image registration. The experimental results show that the proposed method can effectively reduce the error rate of brain MR multimodal medical image registration with rotation and translation transformations (average 0.43mm and 0.60mm) respectively, whose accuracy is better compared to state-of-the-art image registration methods.

EFFECTS OF PARTICLE RESONANCE ON DISPERSION OF ELASTIC WAVES IN PARTICULATE COMPOSITES

  • Kim, J.Y.;Ih, J.G.;Lee, B.H.
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1994.06a
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    • pp.734-739
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    • 1994
  • Elastic wave propagation in discrete random medium is studied to evaluate the effects of particle resonance on dispersion and attenuation of composite materials containing spherical inclusions. The frequency-dependent wave speed and attenuation coefficient can be obtained from proposed self-consistent method. It can be observed that the abrupt increase of effective wave speed and the concurrent peak of attenuation at low frequency is due to the lowest resonance of particles, whereas those in high frequency region are due to higher ones. The lowest resonance is mainly caused by the density mismatch and higher resonances by the stiffness mismatch between matrix and particles. The dispersion and attenuation of elastic waves in particulate composites are affected by the lowest resonance much than by higher ones.

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Ordered Hybrid Nanomaterials from Self-Assembled Polymeric Building Blocks

  • Kim, Dong-Ha
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.309-309
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    • 2006
  • Latest developments on hybrid nanostructured materials fabricated by applying self-assembly strategies on organic/inorganic nanotemplates are discussed. Within this frame, numerous functional nanomaterials including arrays of composite metal/semiconductor nanoparticles, planar waveguides and functional multilayer thin films are generated using self-assembled polymers as templates or building blocks. In particular, surface plasmon resonance based optical sensing is employed to investigate nanofabrication processes occurring in nanoscale dimention. We also suggest unprecedented pathways to hybrid supramolecular multilayer nanoarchitectures in 1D or 2D geometry via layer-by-layer self-assembly.

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High Voltage Transformer Design using Self-Resonant Characteristics of Transformer (트랜스포머의 자가공진 특성을 이용한 고전압 트랜스포머 설계)

  • Lee, Sueng-Hwan;Cho, Dae-Kweon
    • Journal of IKEEE
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    • v.18 no.1
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    • pp.31-36
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    • 2014
  • In this paper, self-resonant characteristics of transformers were analyzed in accordance with changes of characteristics regarding to the stray capacitance, the volume of winding and the winding ratio were organized by formulas. Generally, the stray capacitance is considered as an unnecessary factor in processing transformers design as well as one of the inherent characteristics. In particular, these characteristics can be appeared clearly in the high frequency driving and Electrical resonance occurs in transformer, according to coupling with a magnetic factor at a particular frequency. In the case of high-voltage output applications, such as medical equipments, It is required to output high-voltage gain. Therefor, If Self-Resonant Characteristic is applied to High-Voltage transformer design, Not only the transformer and circuit but also related the system size can be reduced. So we propose it as one of additional high voltage transformer design methods.

Imaging of self-assembled monolayers by surface plasmon microscope (표면 플라즈몬 현미경을 이용한 자기조립 단분자막의 이미징)

  • 표현봉;신용범;윤현철;양해식;김윤태
    • Korean Journal of Optics and Photonics
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    • v.14 no.1
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    • pp.97-102
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    • 2003
  • Multi-channel images of 11-MUA(11-Mercaptoundecanoic acid) and 11-MUOH(11-Mercaptoundecanol) self-assembled monolayers were obtained by using two-dimensional surface plasmon resonance (SPR) absorption. The patterning process was simplified by exploiting direct photo-oxidation of thiol bonding (photolysis) instead of conventional photolithography. Sharper images were resolved by using a white light source in combination with a narrow bandpass filter in the visible region, minimizing the diffraction patterns on the images. The line profile calibration of the image contrast caused by different resonance conditions at each point on the sensor surface (at a fixed incident angle) enables us to discriminate the monolayer thickness in nanometer scale. Furthermore, there is no signal degradation such as photo bleaching or quenching, which are common in the detection methods based on fluorescence.