• Title/Summary/Keyword: scaling effects

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Generalized Integral Hellmann-Feynam Theorem and Configuration Interaction in Crystal Field Theory (광의의 Integral Hellmann-Feynman Theorem과 결정장론에서의 배치간 작용의 효과)

  • Ho Jing Kim
    • Journal of the Korean Chemical Society
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    • v.20 no.3
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    • pp.198-205
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    • 1976
  • The integral Hellmann-Feynman Theorem of Parr is generalized to give a full significance to the off-diagonal form, and certain aspects of it are discussed. By use of the generalized form of the theorem, effects of configuration interaction to the crystal field theory are examined, taking perturbation energies of all order collectively into account. Thus, it is shown that there do not exist, especially when the field is strong, the radial integral which is common to all states characterized by ${\Gamma}$, S and m, and could be parametrized. If, however, one restricts the perturbing excited states only to those angularly undistorted and radially equally distorted, there results simple scaling of the crystal field parameter 10 Dq and Condon-Slater parameter $F^n$ defined within the framework of the classical crystal field theory.

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COMBINED LATTICE-BOLTZMANN AND MOLECULAR-DYNAMICS SIMULATION OF BIOPOLYMER TRANSLOCATION THROUGH AN ARTIFICIAL NANO-PORE (나노 세공을 지나는 생체고분자 운동에 대한 격자-볼츠만과 분자동역학에 의한 수치해석)

  • Alapati, Suresh;Kang, Sang-Mo;Suh, Yong-Kweon
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.97-102
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    • 2009
  • Translocation of biopolymers such as DNA and RNA through a nano-pore is an important process in biotechnology applications. The translocation process of a biopolymer through an artificial nano-pore in the presence of a fluid solvent is simulated. The polymer motion is simulated by Langevin molecular dynamics (MD) techniques while the solvent dynamics are taken into account by lattice-Boltzmann method (LBM). The hydrodynamic interactions are considered explicitly by coupling the polymer and solvent through the frictional and the random forces. From simulation results we found that the hydrodynamic interactions between polymer and solvent speed-up the translocation process. The translocation time ${\tao}_T$ scales with the chain length N as ${{\tau}_T}^{\propto}N^{\alpha}$. The value of scaling exponents($\alpha$) obtained from our simulations are $1.29{\pm}0.03$ and $1.41{\pm}0.03$, with and without hydrodynamic interactions, respectively. Our simulation results are in good agreement with the experimentally observed value of $\alpha$, which is equal to $1.27{\pm}0.03$, particularly when hydrodynamic interaction effects are taken into account.

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Simplified approach for symbol error rate analysis of SC-FDMA scheme over Rayleigh fading channel

  • Trivedi, Vinay Kumar;Sinha, Madhusudan Kumar;Kumar, Preetam
    • ETRI Journal
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    • v.40 no.4
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    • pp.537-545
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    • 2018
  • In this paper, we present a comprehensive analytical study of the symbol error rate (SER) of single-carrier frequency-division multiple access (SC-FDMA) with zero-forcing frequency domain equalization (ZF-FDE) over a Rayleigh fading channel. SC-FDMA is considered as a potential waveform candidate for fifth-generation (5G) radio access networks (RANs). First, the $N_C$ fold convolution of the noise distribution of an orthogonal frequency-division multiplexing (OFDM) system is computed for each value of the signal-to-noise ratio (SNR) in order to determine the noise distribution of the SC-FDMA system. $N_C$ is the number of subcarriers assigned to a user or the size of the discrete Fourier transform (DFT) precoding. Here, we present a simple alternative method of calculating the SER by simplifying the $N_C$ fold convolution using time and amplitude scaling properties. The effects of the $N_C$ fold convolution and SNR over the computation of the SER of the SC-FDMA system has been separated out. As a result, the proposed approach only requires the computation of the $N_C$ fold convolution once, and it is used for different values of SNR to calculate the SER of SC-FDMA systems.

Efficient Use of Unused Spare Columns for Reducing Memory Miscorrections

  • Jung, Ji-Hun;Ishaq, Umair;Song, Jae-Hoon;Park, Sung-Ju
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.3
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    • pp.331-340
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    • 2012
  • In the deep sub-micron ICs, growing amounts of on-die memory and scaling effects make embedded memories increasingly vulnerable to reliability and yield problems. Spare columns are often included in memories to repair defective cells or bit lines during production test. In many cases, the repair process will not use all spare columns. Schemes have been proposed to exploit these unused spare columns to store additional check bits which can be used to reduce the miscorrection probability for triple errors in single error correction-double error detection (SEC-DED). These additional check bits increase the dimensions of the parity check matrix (H-matrix) requiring extra area overhead. A method is proposed in this paper to efficiently fill the extra rows of the H-matrix on the basis of similarity of logic between the other rows. Optimization of the whole H-matrix is accomplished through logic sharing within a feasible operating time resulting in reduced area overhead. A detailed implementation using fuse technology is also proposed in this paper.

Curie Temperature Shift in Gadolinium Films due to Finite-Size Effects (유한 효과에 의한 Gadolinium 박막의 Curie온도 이동)

  • Rhee, Il-Su;Chu, Gyo-Jin;Lee, Eui-Wan;Lee, Sang-Yun;Lee, Chong-Yong;Kim, Yaung-Soo;Kim, Dong-Lak;Ri, H.C.
    • Korean Journal of Materials Research
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    • v.4 no.6
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    • pp.710-714
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    • 1994
  • We determine the Curie temperature of thin gadolinium films by the measurement of magnetization as a function of temperature. From these data, we observe the Curie temperature shift in films from the bulk value, and also see the systematic behavior of this shift with thicknesses of films, that is, the larger the shift is, the thinner the film is. In this paper, we analyze and explain these results in light of finite-size scaling theory.

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Numerical study of 10-year-old child forearm injury

  • Mao, Haojie;Cai, Yun;Yang, King H.
    • Advances in biomechanics and applications
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    • v.1 no.3
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    • pp.143-158
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    • 2014
  • Forearm fractures in children are very common among all pediatric fractures. However, biomechanical investigations on the pediatric forearm are rather scarce, partially due to the complex anatomy, closely situated, interrelated structures, highly dynamic movement patterns, and lack of appropriate tools. The purpose of this study is to develop a computational tool for child forearm investigation and characterize the mechanical responses of a backward fall using the computational model. A three-dimensional 10-year-old child forearm finite element (FE) model, which includes the ulna, radius, carpal bones, metacarpals, phalanges, cartilages and ligaments, was developed. The high-quality hexahedral FE meshes were created using a multi-block approach to ensure computational accuracy. The material properties of the FE model were obtained by scaling reported adult experimental data. The design of computational experiments was performed to investigate material sensitivity and the effects of relevant parameters in backward fall. Numerical results provided a spectrum of child forearm responses with various effective masses and forearm angles. In addition, a conceptual L-shape wrist guard design was simulated and found to be able to reduce child distal radius fracture.

Designing an Input Parameters Setting Model for Reducing the Difficulty of Input Parameters Estimations in Cross Impact Analysis (기술상호효과분석의 입력변수 추정 난이도 경감을 위한 입력변수 설정모형의 설계)

  • Jun, Jungchul;Kwon, Cheolshin
    • Journal of the Korean Operations Research and Management Science Society
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    • v.42 no.2
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    • pp.35-48
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    • 2017
  • As the technology convergence paradigm emerges, the need for "CIA techniques" to analyze the mutual effects of technology is increasing. However, since the CIA input parameter estimation is difficult, the present study suggests a "CIA input parameter setting model" to alleviate the difficulty of CIA input parameter estimation. This paper is focused on the difference of measurement difficulty by each scale which expert's estimation behavior was defined as measurement activity quantifying the judgment of future technology. Therefore, this model is designed to estimate the input variable as a sequence or isometric scale that is relatively easy to measure, and then converts it into a probability value. The input parameter setting model of the CIA technique consists of three sub-models : 'probability value derivation model', 'influence estimation model', and 'impact value calculation model', in order to develop a series of models the Thurstone V model, Regression Analysis, etc has been used.

Gap: A Study on the Influence of New Measurement Method on Consumers' Decision Making

  • Yang, Hoe-Chang;Cho, Hee-Young;Kim, Young-Ei
    • Journal of Distribution Science
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    • v.15 no.1
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    • pp.51-56
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    • 2017
  • Purpose - The study verified the effects of consumers' knowledge perception upon word-of-mouth intention and purchase intention of consumers who were exposed to a lot of information, and examined consumer's behavior from multi-dimensional points of view. Research design, data, and methodology - The study conducted the test of difference between consumer's cognition on importance and satisfaction of HMR product by gap of HMR (Home Meal Replacement) product for IPA analysis. The consumer's reliability and words-of-mouth were measured by the questionnaire method with 4 questions according to Likert 7-point scale. Conversion into z-score removed the difference of variables. Results - The causal relation model for importance, satisfaction and gap, not relying upon multi-dimensional scaling and others, could construct causal relation model to give implications. Difference (d) of the products could lessen consumer's reliability to increase consumer's knowledge perception, word-of-mouth intention, knowledge perception, and purchase intention. Therefore, enterprises should make an effort to lessen consumers' complaint for the products and to elevate consumers' reliability. Enterprises also try to give consumers exact information and to promote purchase intention. Conclusions - Difference (d) of consumers' complaint and/or disappointment decreased consumers' reliability to increase knowledge perception. Enterprises should supply consumers with products according to their requirements to minimize the gap and to give them proper information.

DYNAMICS OF TYPE Ia SNRs WITH DIFFERENT DENSITY DISTRIBUTIONS : FROM EJECTA-DOMINANT TO SEDOV- TAYLOR STAGES (분출물 밀도분포에 따른 Ia형 초신성 잔해의 동력학 : 분출물 우세단계에서 세도브-테일러 단계)

  • CHOE SEUNG-URN;JUNG HYUN-CHUL
    • Publications of The Korean Astronomical Society
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    • v.13 no.1 s.14
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    • pp.135-147
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    • 1998
  • We have simulated the interaction of supernova remnants with constant ambient medium to explore the dynamics of Type Ia supernova remnant. We assumed the supernova ejecta density distribution of the central constant and the outer power-law density distribution$({\rho}{\propto}{\gamma}^{-n})$. We have calculated four different cases with different n. By scaling the length and time scales from the initial parameters-ejecta mass, ejecta energy, the ambient density, we could compare effects of the different density distribution of the ejecta on the dynamics of the SNRs. The radius of the outer forward shock converges the Sedov-Talyor solution at t' = 2.3 when the swept-up mass is 8 times of the ejecta mass. On the other hand, the motion of the reverse shock are largely affected by n. The ejecta with smaller n takes comparably long time to thermalize the whole ejecta at $t'{\simeq}5.3,\;M_{sw}{\simeq}18M_{ej}$. We have applied our calculated results to obtain the ejecta density distributions of Tycho and SN1006 with $n{\simeq}6$.

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Comparative Study on The Numerical Simulation for The Back-Layer of The Tunnel Fire-Driven Flow with LES and RANS (터널화재유동의 역기류 해석을 위한 LES 및 RANS 결과의 비교 고찰)

  • Jang, Yong-Jun;Kim, Hag-Beom;Kim, Jin-Ho;Han, Seok-Youn
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.3
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    • pp.156-163
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    • 2009
  • In this study, comparative analysis on the back-layer phenomena in the tunnel-fire driven flow is performed using numerical simulation with LES and RANS. FDS(Fire Dynamics Simulator) code is employed to calculate the fire-driven turbulent flow for LES and Smartfire code is used for RANS. Hwang and Wargo's data of scaling tunnel fire experiment are employed to compare with the present numerical simulation. The modeled tunnel is 5.4m(L) ${\times}$ 0.4m(W) ${\times}$ 0.3m(H). Heat Release Rate (HRR) of fire is 3.3kW and ventilation-velocity is 0.33m/s in the main stream. The various grid-distributions are systematically tested with FDS code to analyze the effects of grid size. The LES method with FDS provides an improved back-layer flow behavior in comparison with the RANS (${\kappa}-{\epsilon}$) method by Smartfire. The FDS solvers, however, overpredict the velocity in the center region of flow which is caused by the defects in the tunnel-entrance turbulence strength and in the near-wall turbulent flow in FDS code.