• Title/Summary/Keyword: Physics-based model

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Physics-based Modeling of Low Temperature Co-fired Ceramic Helical Inductors (LTCC Helical 인덕터의 Physics-based 모델링)

  • Heo, Keun;Lim, Ju-Hwan;Hwang, Sung-Woo
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.601-602
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    • 2006
  • A physics-based equivalent circuit model for LTCC Helical type Inductors is presented. All of the electromagnetic couplings between conductors are included in the model and the number of optimized parameters is minimized. The model can predict the measured results upto 12 GHz.

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Using Semantic Knowledge in the Uyghur-Chinese Person Name Transliteration

  • Murat, Alim;Osman, Turghun;Yang, Yating;Zhou, Xi;Wang, Lei;Li, Xiao
    • Journal of Information Processing Systems
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    • v.13 no.4
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    • pp.716-730
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    • 2017
  • In this paper, we propose a transliteration approach based on semantic information (i.e., language origin and gender) which are automatically learnt from the person name, aiming to transliterate the person name of Uyghur into Chinese. The proposed approach integrates semantic scores (i.e., performance on language origin and gender detection) with general transliteration model and generates the semantic knowledge-based model which can produce the best candidate transliteration results. In the experiment, we use the datasets which contain the person names of different language origins: Uyghur and Chinese. The results show that the proposed semantic transliteration model substantially outperforms the general transliteration model and greatly improves the mean reciprocal rank (MRR) performance on two datasets, as well as aids in developing more efficient transliteration for named entities.

APPLICATION OF FUZZY LOGIC IN THE CLASSICAL CELLULAR AUTOMATA MODEL

  • Chang, Chun-Ling;Zhang, Yun-Jie;Dong, Yun-Ying
    • Journal of applied mathematics & informatics
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    • v.20 no.1_2
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    • pp.433-443
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    • 2006
  • In [1], they build two populations' cellular automata model with predation based on the Penna model. In this paper, uncertain aspects and problems of imprecise and vague data are considered in this model. A fuzzy cellular automata model containing movable wolves and sheep has been built. The results show that the fuzzy cellular automata can simulate the classical CA model and can deal with imprecise and vague data.

Development of a Physics-Based Design Framework for Aircraft Design using Parametric Modeling

  • Hong, Danbi;Park, Kook Jin;Kim, Seung Jo
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.3
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    • pp.370-379
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    • 2015
  • Handling constantly evolving configurations of aircraft can be inefficient and frustrating to design engineers, especially true in the early design phase when many design parameters are changeable throughout trade-off studies. In this paper, a physics-based design framework using parametric modeling is introduced, which is designated as DIAMOND/AIRCRAFT and developed for structural design of transport aircraft in the conceptual and preliminary design phase. DIAMOND/AIRCRAFT can relieve the burden of labor-intensive and time-consuming configuration changes with powerful parametric modeling techniques that can manipulate ever-changing geometric parameters for external layout of design alternatives. Furthermore, the design framework is capable of generating FE model in an automated fashion based on the internal structural layout, basically a set of design parameters describing the structural members in terms of their physical properties such as location, spacing and quantities. The design framework performs structural sizing using the FE model including both primary and secondary structural levels. This physics-based approach improves the accuracy of weight estimation significantly as compared with empirical methods. In this study, combining a physics-based model with parameter modeling techniques delivers a high-fidelity design framework, remarkably expediting otherwise slow and tedious design process of the early design phase.

Comparison of soil erosion simulation between empirical and physics-based models

  • Yeon, Min Ho;Kim, Seong Won;Jung, Sung Ho;Lee, Gi Ha
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.172-172
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    • 2020
  • In recent years, soil erosion has come to be regarded as an essential environmental problem in human life. Soil erosion causes various on- and off-site problems such as ecosystem destruction, decreased agricultural productivity, increased riverbed deposition, and deterioration of water quality in streams. To solve these problems caused by soil erosion, it is necessary to quantify where, when, how much soil erosion occurs. Empirical erosion models such as the Universal Soil Loss Equation (USLE) family models have been widely used to make spatially distributed soil erosion vulnerability maps. Even if the models detect vulnerable sites relatively well by utilizing big data related to climate, geography, geology, land use, etc. within study domains, they do not adequately describe the physical process of soil erosion on the ground surface caused by rainfall or overland flow. In other words, such models remain powerful tools to distinguish erosion-prone areas at the macro scale but physics-based models are necessary to better analyze soil erosion and deposition and eroded particle transport. In this study, the physics-based Surface Soil Erosion Model (SSEM) was upgraded based on field survey information to produce sediment yield at the watershed scale. The modified model (hereafter MoSE) adopted new algorithms on rainfall kinematic energy and surface flow transport capacity to simulate soil erosion more reliably. For model validation, we applied the model to the Doam dam watershed in Gangwon-do and compared the simulation results with the USLE outputs. The results showed that the revised physics-based soil erosion model provided more improved and reliable simulation results than the USLE in terms of the spatial distribution of soil erosion and deposition.

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Theoretical Results for a Dipole Plasmonic Mode Based on a Forced Damped Harmonic Oscillator Model

  • Tongtong Hao;Quanshui Li
    • Current Optics and Photonics
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    • v.7 no.4
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    • pp.449-456
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    • 2023
  • The localized surface-plasmon resonance has drawn great attention, due to its unique optical properties. In this work a general theoretical description of the dipole mode is proposed, using the forced damped harmonic oscillator model of free charges in an ellipsoid. The restoring force and driving force are derived in the quasistatic approximation under general conditions. In this model, metal is regarded as composed of free charges and bound charges. The bound charges form the dielectric background which has a dielectric function. Those free charges undergo a collective motion in the dielectric background under the driving force. The response of free charges will not be included in the dielectric function like the Drude model. The extinction and scattering cross sections as well as the damping coefficient from our model are verified to be consistent with those based on the Drude model. We introduce size effects and modify the restoring and driving forces by adding the dynamic depolarization factor and the radiation damping term to the depolarization factor. This model provides an intuitive physical picture as well as a simple theoretical description of the dipole mode of the localized surface-plasmon resonance based on free-charge collective motion.

Description Capability of a Simple Phenomenological Constitutive Model for High-Strain-Rate Plasticity Data (간단한 현상학적 구성방정식의 고속 유동응력 기술 능력)

  • Shin, Hyun-Ho;Kim, Jong-Bong
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.10a
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    • pp.190-193
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    • 2009
  • A recently reported simple phenomenological constitutive model (SK) demonstrated comparable or better data description capability to/than one of the rigorous and physics-based models, the PTW model. The simple SK model is believed to be an efficient model for practical applications where an extensive computation is needed, and can serve as a rigorous comparison standard for the development of a physics-based model.

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Power control of CiADS core with the intensity of the proton beam

  • Yin, Kai;Ma, Wenjing;Cui, Wenjuan;He, Zhiyong;Li, Xinxin;Dang, Shiwu;Yang, Feng;Guo, Yuhui;Duan, Limin;Li, Meng;Hou, Yikai
    • Nuclear Engineering and Technology
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    • v.54 no.4
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    • pp.1253-1260
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    • 2022
  • This paper reports the control method for the core power of the China initiative Accelerator Driven System (CiADS) facility. In the CiADS facility, an intense external neutron source provided by a proton accelerator coupled to a spallation target is used to drive a sub-critical reactor. Without any control rod inside the sub-critical reactor, the core power is controlled by adjusting the proton beam intensity. In order to continuously change the beam intensity, an adjustable aperture is considered to be used at the Low Energy Beam Transport (LEBT) line of the accelerator. The aperture size is adjusted based on the Proportional Integral Derivative (PID) controllers, by comparing either the setting beam intensity or the setting core power with the measured value. To evaluate the proposed control method, a CiADS core model is built based on the point reactor kinetics model with six delayed neutron groups. The simulations based on the CiADS core model have indicated that the core power can be controlled stably by adjusting the aperture size. The response time in the adjustment of the core power depends mainly on the adjustment time of the beam intensity.

The Magnetoresistance in Iron-based Superconductors

  • Lv, B.;Xie, R.B.;Liu, S.L.;Wu, G.J.;Shao, H.M.;Wu, X.S.
    • Journal of Magnetics
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    • v.16 no.2
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    • pp.192-195
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    • 2011
  • The phase transition of vortex matter from solid to liquid was studied in iron-based superconductors. Based on the traditional vortex glass theory, we have examined the magnetoresistivity data of iron-based superconductors using our extended thermal activation model: $\rho(B,T)=\rho((T-T_g(B))/(T_c(0)-T_g(B)))^{v(z-1)}$. We predict that the magnetic field-dependent area S + $S_0$ which integrates $\rho$ with T is proportional to $B^{\beta}$, where ${\beta}$ is the vortex glass transition exponent. From our calculation, the vortex glass transition exponent is 0.33, close to the exponent of area $S_0$ + S is 0.31 in $SmO_{0.9}F_{0.1}FeAs$; the exponent of area S is 0.63, which is close to the irreversibility line exponent 2/3. Both of the results show the validity of our model. In addition, our model is shown to be effective in describing irreversibility behavior in layered superconductors.

Computational Science-based Research on Dark Matter at KISTI

  • Cho, Kihyeon
    • Journal of Astronomy and Space Sciences
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    • v.34 no.2
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    • pp.153-159
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    • 2017
  • The Standard Model of particle physics was established after discovery of the Higgs boson. However, little is known about dark matter, which has mass and constitutes approximately five times the number of standard model particles in space. The cross-section of dark matter is much smaller than that of the existing Standard Model, and the range of the predicted mass is wide, from a few eV to several PeV. Therefore, massive amounts of astronomical, accelerator, and simulation data are required to study dark matter, and efficient processing of these data is vital. Computational science, which can combine experiments, theory, and simulation, is thus necessary for dark matter research. A computational science and deep learning-based dark matter research platform is suggested for enhanced coverage and sharing of data. Such an approach can efficiently add to our existing knowledge on the mystery of dark matter.