• Title/Summary/Keyword: 3D-based equivalent model

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Design Rules of Hybrid Stepping Machine for Free Piston Engine

  • Jeong, Sung-In
    • Journal of Electrical Engineering and Technology
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    • v.12 no.3
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    • pp.1219-1226
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    • 2017
  • This paper presents the hybrid stepping machine for linear oscillating generators. The focus of the work is the suggestion of the improved model through the comparison of proposed models ; new flux concentrating PMs mover of the hybrid stepping generator is proposed based on the symmetrical and non-symmetrical stator cores of the surface mounted PMs mover, and non-slanted PMs and slanted PMs of the flux concentrating PMs mover. It is achieved using equivalent magnetic circuit considering leakage elements. Finally, this study suggests new hybrid stepping structure of linear oscillating generator.

Magnetic Field Analysis Due to the Remanent Magnetization Distributed on a Ferromagnetic Thin Plate by using Equivalent Magnetic Models and Material Sensitivity (등가 자기모델과 매질민감도법을 이용한 강자성체 판에 분포하는 영구자화에 기인한 자기장 신호분석)

  • Jeung, Gi-Woo;Kim, Dong-Wook;Kim, Dong-Hun;Yang, Chang-Seob;Chung, Hyun-Ju
    • Journal of the Korean Magnetics Society
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    • v.20 no.3
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    • pp.100-105
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    • 2010
  • For predicting magnetic signals due to the remanent magnetization distributed on a ferromagnetic ship hull, this paper presents an efficient methodology for solving inverse problems, where the material sensitivity analysis based on the continuum mechanics is combined with the equivalent magnetic models. To achieve this, the 3D magnetic charge model and the magnetic dipole moment model are introduced and material sensitivity formulae applicable to each equivalent model are derived. The formulae offer the first-order gradient information of an objective function with respect to the variation of the magnetic charge or magnetic dipole and so an optimal solution can be easily obtained regardless of the number of design variables. To validate the proposed method, the numerical results are comparison with the real measurements of a mock-up model.

Dielectric Properties of $SrTiO_3$-based varistors ($SrTiO_3$ 바리스터의 유전특성)

  • Kang, D.H.;Park, I.Y.;Shim, J.G.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1471-1473
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    • 2000
  • In this study capacitance and dielectric loss factor were measured with low-voltage signal and the simulation of equivalent circuits for the data were conducted. As the result it was showed that the equivalent circuit model considered the gram-boundary structure with semiconducting layer, dielectric layer and depletion layer was well approximated with the observed data. Various parameters were determined by a optimum curve-fitting method and could be used to analyze the varistor-voltages and the nonlinear coefficient of varistors. It also seems that the proposed equivalent circuit model will be adopted for other BL type varistors.

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An Efficient Model to Calculate Axial Natural Vibration Frequency of Power Transformer Winding

  • Li, Kaiqi;Guo, Jian;Liu, Jun;Zhang, Anhong;Yu, Shaojia
    • Journal of Magnetics
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    • v.21 no.3
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    • pp.431-436
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    • 2016
  • In the design of transformer winding, natural vibration frequency is an important parameter. This paper presents a 2D model to calculate axial vibration natural frequency of power transformer winding based on the elastic dynamics theory, and according to the elastic support equivalent principle of radial pressboards. The 3D model to calculate natural vibration frequency can be simplified as a 2D one as the support of pressboards on the winding is same. It is verified that results of the 2D model are consistent with those of 3D one, but the former can achieve much higher calculation efficiency. It shows that increasing the width and number of pressboards can improve axial natural frequency through formula analysis and simulation, and also the relations between the changes of axial pre-compression and axial natural vibration frequency on the windings are investigated. Finally, the proposed 2D model's effectiveness is proved when compared with tested ones.

Characteristic Prediction and Analysis of 3-D Embedded Passive Devices (3차원 매립형 수동소자의 특성 예측 및 분석에 대한 연구)

  • Shin, Dong-Wook;Oh, Chang-Hoon;Lee, Kyu-Bok;Kim, Jong-Kyu;Yun, Il-Gu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.607-610
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    • 2003
  • The characteristic prediction and analysis of 3-dimensional (3-D) solenoid-type embedded inductors is investigated. The four different structures of 3-D inductor are fabricated by using low-temperature cofired ceramic (LTCC) process. The circuit model parameters of the each building block are optimized and extracted using the partial element equivalent circuit method and HSPICE circuit simulator. Based on the model parameters, predictive modeling is applied for the structures composed of the combination of the modeled building blocks. And the characteristics of test structures, such as self-resonant frequency, inductance and Q-factor, are analyzed. This approach can provide the characteristic conception of 3-D solenoid embedded inductors for structural variations.

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High Pass Filter Design Using Folded Coplanar Waveguide CRLH Transmission Line

  • Yang, Lei;Yang, Doo-Yeong
    • International Journal of Contents
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    • v.11 no.3
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    • pp.63-68
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    • 2015
  • A novel unit cell for a high pass filter was designed based on a composite right/left-handed structure that uses a folded coplanar waveguide. The equivalent circuit model for the unit cell was extracted from the geometry of the unit cell, and the effect of each main parameter of the unit cell was analyzed. The equations to calculate the immittance values of the equivalent circuit elements were formulated, and moreover, the dispersion characteristics and energy the distributions of the electromagnetic fields were simulated to determine the characteristics of the composite right/left-handed structure. Finally, the high pass filters were implemented as a series of the proposed unit cells. We show that the experimental results were in good agreement with those obtained from the simulation. Thus, the high pass filter was found to achieve a baseband insertion loss of 3 dB and a stopband attenuation of 70 dB.

Energy-based numerical evaluation for seismic performance of a high-rise steel building

  • Zhang, H.D.;Wang, Y.F.
    • Steel and Composite Structures
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    • v.13 no.6
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    • pp.501-519
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    • 2012
  • As an alternative to current conventional force-based assessment methods, the energy-based seismic performance of a code-designed 20-storey high-rise steel building is evaluated in this paper. Using 3D nonlinear dynamic time-history method with consideration of additional material damping effect, the influences of different restoring force models and P-${\Delta}/{\delta}$ effects on energy components are investigated. By combining equivalent viscous damping and hysteretic damping ratios of the structure subjected to strong ground motions, a new damping model, which is amplitude-dependent, is discussed in detail. According to the analytical results, all energy components are affected to various extents by P-${\Delta}/{\delta}$ effects and a difference of less than 10% is observed; the energy values of the structure without consideration of P-${\Delta}/{\delta}$ effects are larger, while the restoring force models have a minor effect on seismic input energy with a difference of less than 5%, but they have a certain effect on both viscous damping energy and hysteretic energy with a difference of about 5~15%. The paper shows that the use of the hysteretic energy at its ultimate state as a seismic design parameter has more advantages than seismic input energy since it presents a more stable value. The total damping ratio of a structure consists of viscous damping ratio and hysteretic damping ratio and it is found that the equivalent viscous damping ratio is a constant for the structure, while the equivalent hysteretic damping ratio approximately increases linearly with structural response in elasto-plastic stage.

Case Study on Influential Factors of Nonlinear Response History Analysis - Focused on 1989 Loma Prieta Earthquake - (비선형 응답이력해석의 영향인자에 대한 사례연구 - 1989 Loma Prieta 지진 계측기록을 중심으로 -)

  • Liu, Qihang;Lee, Jin-Sun
    • Journal of the Korean Geotechnical Society
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    • v.33 no.12
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    • pp.45-58
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    • 2017
  • As many seismic codes for various facilities are changed into a performance based design code, demand for a reliable nonlinear response-history analysis (RHA) arises. However, the equivalent linear analysis has been used as a standard approach since 1970 in the field of site response analysis. So, the reliability of nonlinear RHA should be provided to be adopted in replace of equivalent linear analysis. In this paper, the reliability of nonlinear RHA is reviewed for a layered soil layer using Loma Prieta earthquake records in 1989. For this purpose, the appropriate way for selecting nonlinear soil models and the effect of base boundary condition for 3D analysis are evaluated. As a result, there is no significant differences between equivalent linear and nonlinear RHA. In case of 3D analysis, absorbing boundary condition should be applied at base to prevent rocking motion of the whole model.

Effective Equivalent Finite Element Model for Impact Limiter of Nuclear Spent Fuel Shipping Cask made of Sandwich Composites Panels (사용후 핵연료 수송용기 샌드위치 복합재 충격완충체의 유효등가 유한요소 모델 제시)

  • Kang, Seung-Gu;Im, Jae-Moon;Shin, Kwang-Bok;Choi, Woo-Suk
    • Composites Research
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    • v.28 no.2
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    • pp.58-64
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    • 2015
  • The purpose of this paper is to suggest the effective equivalent finite element model for the impact limiter of a nuclear spent fuel shipping cask made of sandwich composite panels. The sandwich composite panels were composed of a metallic facesheet and a core material made of urethane foam, balsa wood and red wood, respectively. The effective equivalent finite element model for the impact limiter was proposed by comparing the results of low-velocity impact test of sandwich panels. An explicit finite element analysis based on LS-DYNA 3D was done in this study. The results showed that the solid elements were recommended to model the facesheet and core of sandwich panels for impact limiter compared to combination modeling method, in which the layered shell element for facesheet and solid element for core material are used. In particular, the solid element for balsa and red wood core materials should be modeled by the element elimination approach.

The Case Study : The Efficiency of Using UAV and 3D-model for Mine Reclamation Work Monitoring (무인항공기와 3차원 지표모델의 광해방지사업 모니터링에 대한 효율성 고찰)

  • Kim, Seyoung;Yu, Jaehyung;Shin, Ji Hye;Lee, Gilljae
    • Journal of the Mineralogical Society of Korea
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    • v.30 no.1
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    • pp.1-9
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    • 2017
  • This study investigated the effectiveness of Unmanned Aerial Vehicle (UAV) and 3D modeling on mine reclamation monitoring. The high spatial resolution of 3.8 cm ortho-mosaic image and Digital Elevation Model (DEM) are constructed based on UAV air survey. The ortho-mosaic image effectively shows mine reclamation activities and recognize objects and topological changes in the image. The comparative analysis of 3D models between UAV based DEM and report based DEM reveals that total amount of $268,672m^3$ additional dumping of contaminated soil is equivalent to 710,000 ton. It concludes that a UAV based survey enables high accuracy spatial information extraction for mine reclamation activities with high efficiency. It is expected that UAV survey will be very effectively used for preliminary data acquisition and project monitoring for mine reclamation activities.