• Title/Summary/Keyword: Dependent

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A Method of Computing the Frequency-Dependent Ground Impedance of Horizontally-buried Wires (수평으로 매설된 도선의 접지임피던스의 주파수의존성을 계산하는 기법)

  • Cho, Sung-Chul;Lee, Bok-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.5
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    • pp.745-752
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    • 2016
  • The parameters of Debye's equation were applied to analyze the frequency-dependent ground impedance of horizontally-buried wires. We present a new method, based on Debye's equation, of analyzing the effect of polarization on frequency-dependent ground impedance. The frequency-dependent ground impedances of a horizontally-buried wire are directly measured and calculated by applying sinusoidal current in the frequency range of 100 Hz to 10 MHz. Also, the results obtained in this work were compared with the data calculated from empirical equations and commercial programs. A new methodology using the delta-gap source model is proposed in order to calculate frequency-dependent ground impedance when the ground current is injected at the middle-point of the horizontal ground electrode. The high frequency ground impedance of horizontal electrodes longer than 30 m is larger or equal to its low frequency ground resistance. Consequently, the frequency-dependent ground impedance simulated with the proposed method is in agreement with the experimental data, and the validity of the computational simulation approach is confirmed.

Heat Transfer Behavior of Viscoelastic Fluid including buoyancy effect with Modified Temperature Dependent Viscosity Model in a Rectangular Duct (수정점도 모델을 이용한 직사각형 덕트에서의 부력을 고려한 점탄성 유체의 열전달 특성)

  • Sohn C. H.;Jang J. H.
    • 한국전산유체공학회:학술대회논문집
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    • 1999.05a
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    • pp.192-198
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    • 1999
  • The present study proposes modified temperature-dependent non-Newtonian viscosity model and investigates flow characters and heat transfer enhancement of the viscoelastic non-Newtonian fluid in a 2:1 rectangular duct. The proposed modified temperature dependent viscosity model has non-zero value near the high temperature and high shear rate region while on the existing viscosity models have zero value. Two versions of thermal boundary conditions involving difference combination of heated walls and adiabatic walls are analyzed in this study. The combined effect of temperature dependent viscosity, buoyancy, and secondary flow caused by second normal stress difference are ail considered. The Reiner-Rivlin model is adopted as a viscoelastic fluid model to simulate the secondary flow caused by second normal stress difference. Calculated Nusselt numbers by the modified temperature-dependent viscosity model gives under prediction than the existing temperature-dependent viscosity model in the regions of thermally developed with same secondary normal stress difference coefficients with experimental results in the regions of thermally developed. The heat transfer enhancement of the viscoelastic fluid in a 2:1 rectangular duct is highly dependent on the secondary flow caused by the magnitude of second normal stress difference.

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Assessment of time-dependent behaviour of rocks on concrete lining in a large cross-section tunnel

  • Mirzaeiabdolyousefi, Majid;Nikkhah, Majid;Zare, Shokrollah
    • Geomechanics and Engineering
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    • v.29 no.1
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    • pp.41-51
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    • 2022
  • Tunneling in rocks having the time-dependent behavior, causes some difficulties like tunnel convergence and, as a result, pressure on concrete lining; and so instability on this structure. In this paper the time-dependent behaviour of squeezing phenomenon in a large cross section tunnel was investigated as a case study: Alborz tunnel. Then, time-dependent behaviour of Alborz tunnel was evaluated using FLAC2D based on the finite difference numerical method. A Burger-creep viscoelastic model was used in numerical analysis. Using numerical analysis, the long-time effect of squeezing on lining stability was simulated.This study is done for primary lining (for 2 years) and permanent lining (for 100 years), under squeezing situations. The response of lining is discussed base on Thrust Force-Bending Moment and Thrust Force-Shear Force diagrams analysing. The results determined the importance of consideration of time-dependent behaviour of tunnel that structural forces in concrete lining will grow in consider with time pass and after 70 years can cause instability in creepy rock masses section of tunnel. To show the importance of time-dependent behavior consideration of rocks, elastic and Mohr-Coulomb models are evaluated at the end.

Voxel-wise UV parameterization and view-dependent texture synthesis for immersive rendering of truncated signed distance field scene model

  • Kim, Soowoong;Kang, Jungwon
    • ETRI Journal
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    • v.44 no.1
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    • pp.51-61
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    • 2022
  • In this paper, we introduced a novel voxel-wise UV parameterization and view-dependent texture synthesis for the immersive rendering of a truncated signed distance field (TSDF) scene model. The proposed UV parameterization delegates a precomputed UV map to each voxel using the UV map lookup table and consequently, enabling efficient and high-quality texture mapping without a complex process. By leveraging the convenient UV parameterization, our view-dependent texture synthesis method extracts a set of local texture maps for each voxel from the multiview color images and separates them into a single view-independent diffuse map and a set of weight coefficients for an orthogonal specular map basis. Furthermore, the view-dependent specular maps for an arbitrary view are estimated by combining the specular weights of each source view using the location of the arbitrary and source viewpoints to generate the view-dependent textures for arbitrary views. The experimental results demonstrate that the proposed method effectively synthesizes texture for an arbitrary view, thereby enabling the visualization of view-dependent effects, such as specularity and mirror reflection.

Changes in Phosphatase Activity of the Mouse Uterus during the Estrous Cycle (發情週期에 EK른 생쥐子宮의 Phosphatase 活性의 變化에 관하여)

  • Kim, Moon-Kyoo;Kim, Sung-Rye;Cho, Wan-Kyoo
    • The Korean Journal of Zoology
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    • v.23 no.2
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    • pp.61-68
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    • 1980
  • Quantitative analysis of the activities of transport ATPases as well as alkaline phosphatase of the mouse uterus was carried out during the estrous cycle. Even though the proportional patterns of the enzyme activities were similar each another between the stages of estrous cycle, the absolute activities of the enzymes except $K^+$-dependent and $Na^+$, $K^+$-activated ATPases at the time of estrus were significantly (p<0.025) higher than that at any other time of the estrous cycle. That is, the activities of $K^+$-dependent and $Na^+$, $K^+$-activated ATPases were negligible during the period of time from diestrus to estrus while the little activities (0.04 $\\sim$ 0.05$\\mu$M/mg protein/hr in average, $6\\sim7$% of the total enzyme activity) of these enzymes appeared at the time of metaestrus. On the other hand, at the time of estrus, the activities of $Mg^++$-dependent phosphatase, transport ATPase and alkaline phosphatase were rapidly and tremendously increased to be 0.69 (35%), 0.42 (21%) and 1.58 (79%), respectively. The activity of alkaline phosphatase was in the range of 0.60 $\\sim$ 1.58 (79 $\\sim$ 90%) and predominant throughout the estrous cycle. The activity of $Mg^++$-dependent alkaline phosphatase was estimated as 12 $\\sim$ 16% of the total enzyme activity. Therefore, it is assumed likely that $K^+$-dependent and $Na^+$, $K^+$-activated ATPases are not the main factors to control the fluid accumulation at the time of estrus, but may be the factors to reabsorb the luminal fluid into the uterine epithelium at the time of metaestrus, and that $Mg^++$-dependent phosphatase, transport ATPase and alkaline phosphatase must be closely involved in the secretion of luminal fluid from the epithelial cells of the mouse uterus.

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Three Axioms in Tribology

  • Xie, You-Bai
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.06a
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    • pp.3-10
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    • 2000
  • The undesired situation of development of tribology and its reason is analyzed. The problem comes from insufficient study on the concept system and method system, which can match the name, definition and nature of tribology. The existence of three axioms in tribology is discussed. They are axiom of system dependent, axiom of time dependent and axiom of coupling of behaviors of multi-discipline. A series of lemmas has been deduced from three axioms. It is expected that they can be a foundation to establish the concept system and method system.

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Frequency-Dependent Element Matrices for Vibration Analysis of Piping Systems (배영계의 진동해소를 위한 주파수종속 요표행렬)

  • 양보석;안영홍;최원호
    • Journal of Ocean Engineering and Technology
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    • v.6 no.2
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    • pp.125-132
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    • 1992
  • This paper presents an approach for the derivation of frequency-dependent element matrices for vibration analysis of piping systems containing a moving medium. The dynamic stiffness matrix is deduced from transfer matrix, and, in turn, the frequency-dependent element matrices are derived. Numerical examples show that method gives more accurate results than those obtained using the conventional static shape function based element matrices.

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ON THE COMPLETE CONVERGENCE FOR ARRAYS OF ROWWISE EXTENDED NEGATIVELY DEPENDENT RANDOM VARIABLES

  • Qiu, Dehua;Chen, Pingyan;Antonini, Rita Giuliano;Volodin, Andrei
    • Journal of the Korean Mathematical Society
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    • v.50 no.2
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    • pp.379-392
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    • 2013
  • A general result for the complete convergence of arrays of rowwise extended negatively dependent random variables is derived. As its applications eight corollaries for complete convergence of weighted sums for arrays of rowwise extended negatively dependent random variables are given, which extend the corresponding known results for independent case.

SOLVABILITY OF IMPULSIVE NEUTRAL FUNCTIONAL INTEGRO-DIFFERENTIAL INCLUSIONS WITH STATE DEPENDENT DELAY

  • Karthikeyan, K.;Anguraj, A.
    • Journal of applied mathematics & informatics
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    • v.30 no.1_2
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    • pp.57-69
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    • 2012
  • In this paper, we prove the existence of mild solutions for a first order impulsive neutral differential inclusion with state dependent delay. We assume that the state-dependent delay part generates an analytic resolvent operator and transforms it into an integral equation. By using a fixed point theorem for condensing multi-valued maps, a main existence theorem is established.

STRONG LAW OF LARGE NUMBERS FOR ASYMPTOTICALLY NEGATIVE DEPENDENT RANDOM VARIABLES WITH APPLICATIONS

  • Kim, Hyun-Chull
    • Journal of applied mathematics & informatics
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    • v.29 no.1_2
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    • pp.201-210
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    • 2011
  • In this paper, we obtain the H$\`{a}$jeck-R$\`{e}$nyi type inequality and the strong law of large numbers for asymptotically linear negative quadrant dependent random variables by using this inequality. We also give the strong law of large numbers for the linear process under asymptotically linear negative quadrant dependence assumption.