• Title/Summary/Keyword: Linear relation

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CONVERGENCE OF EXPONENTIALLY BOUNDED C-SEMIGROUPS

  • Lee, Young S.
    • Korean Journal of Mathematics
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    • v.9 no.2
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    • pp.115-121
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    • 2001
  • In this paper, we establish the conditions that a mild C-existence family yields a solution to the abstract Cauchy problem. And we show the relation between mild C-existence family and C-regularized semigroup if the family of linear operators is exponentially bounded and C is a bounded injective linear operator.

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Electromechanical Relationn of metallic heat wires and Its Application to the Estimation of In_situ Stress of Structural Tendons (금속계열선의 전기기계적 상관작용과 긴장력 계측이 가능한 긴장재)

  • Zi Goang-Seup;Jun Ki-Woo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.445-450
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    • 2006
  • It is proposed that the electromechanical relation of the conductive materials with high electrical resistance may be used to estimate the current stress of prestressing tendons. To choose the best conductive material to this end, we studied the electromechanical relations of carbon fibers and metalic heat wires experimentally. It is found that the relation of carbon fibers can be modelled by a parabolic(or hyperbolic) function in the early stage of deformation. However because the relation is not consistent when it is unloaded and reload, carbon fibers are not suitable for this purpose. Metallic heat wires show a consistent linear relation during loading and unloading in the elastic deformation and are suitable for this purpose. To estimate the electromechanics relation of metallic wires, we developed a simple formula based on the rigid plasticity. We propose a new kind of prestressing tendons whose stress can be monitored.

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Relation between lineament and well productivity (지질구조선과 지하수 산출성간의 상관성 평가)

  • Kim Gyu-Beom;Lee Gang-Geun;Lee Jang-Ryong
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2005.04a
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    • pp.85-89
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    • 2005
  • Lineament maps are the important tools that may reveal points of groundwater recharge, flow and development. In particular, groundwater flows and yields in mountainous area, composed of crystalline rocks with many fractures, are governed mainly by the lineaments corresponding to fractures, joints and faults. Lineaments may give important information on the best distribution of wells and their management. For two districts; Pohang and Cheonan, the relationship between lineament and groundwater factors was analyzed. To compare groundwater productivity, storativity, and transmissivity of a well site along the distance to lineament, the distances to lineament was regrouped into five groups with an equal range, 100m, for the Pohang district and they are also divided into five groups with an equal range, 150m, for the Cheonan district. From the results of the Spearman Rank Correlation Analysis and Kendall Analysis for each group, the means of SPC and T of wells which are located near lineaments generally have large values. The means of SPC and T show a reverse linear relationship with a lineament distance, but the means of S shows a disperse distribution and no distinct linear relation. Result of the linear regression model between SPC and lineament length density shows that it will be effective to use the lineament length density map when finding the optimal well site on a regional scale.

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Prediction of $EC_{50}$ of Photobacterium phosphoreum for CAHs and Chlorophenol Derivatives Using QSAR (QSAR방법을 이용한 CAHs와 Chlorophenol 유도체에 대한 $EC_{50}$값 예측)

  • Lee, Hong-Joo;Yoo, Seung-O;Lee, Jeong-Gun;Kim, Byung-Yong;Chun, Uck-Han
    • Microbiology and Biotechnology Letters
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    • v.27 no.1
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    • pp.54-61
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    • 1999
  • Measurement of inhibition of bioluminescence in Photobacterium phosphoreum has been porposed as a sensitive and rapid procedure to monitor toxic substances. However, at first, $EC_{50}$ which shows degree of toxicity to each toxic substances must be calculated. QSAR (Quantitative Structure Activity Relationship) model can be used to estimate $EC_{50}$ to save time and endeavor. Moderately high correlation coefficients ($r^2{\geq}$ 0.97) were calculated from the linear correlation between $EC_{50}$ and molecular connectivity indices of CAHs (chlorinated aliphatic hydrocarbons)such as $^0X$, $^0X^V$, $^1X$, $^2X$ and $^3X^v_c$ and quadratic correlation between $EC_{50}$ and $^0X$, $^0X^V$, $^2X^V$, $^3X_c$, $^3X^V_c$ and P. It shows that the molecular connection indices in carbon structure is contributed to biological characters with linear relation and that in the other one with quadratic relation. The $EC_{50}$ of chlorophenol derivatives had quadratic relation with the value of octanol/water prtition coefficients ($r^2$=0.99) and linear and quadratic relation with the number of chlorine compound (($r^2{\geq}$0.94). This confirms the already known trend of increasing toxicity with increasing ability of a compound to diffuse through cell membrane and number of chlorine substitution.

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Development of the Simplified Analysis Model for RC Structures Considering Plastic Behavior (소성거동을 고려한 RC 구조물의 간략화 해석모델에 관한 연구)

  • 정연주;유영찬
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.3
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    • pp.361-371
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    • 2000
  • RC structure is the composite material system combined concrete and steel showing different plastic behavior. Especially, concrete shows very complex plastic behavior. Therefore, for plastic analysis of RC structures, we have to model carefully each plastic behavior of concrete and steel member. But, because of divergency as well as difficulties and dimensions of modelling, it takes a lot of time and labor or sometimes it is impossible to perform plastic analysis of RC structures. In this study, for simplified plastic analysis of RC structures, we propose material transformation method by homogeneous and isotropic material which have the same plastic property as RC. We generate homogeneous and isotropic material showing the same moment-curvature curves (bi-linear stress-strain relation) as RC members, using bi-linear moment-curvature relation by yielding moment, yielding curvature and ultimate moment, ultimate curvature of RC member. Finally, we prove compatibility in the study by comparing plastic analysis results for various analysis models using transformed material models and RC model.

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SOME LOCAL SPECTRAL PROPERTIES OF T AND S WITH AT - SA = 0

  • Yoo, Jong-Kwang;Han, Hyuk
    • Journal of applied mathematics & informatics
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    • v.26 no.5_6
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    • pp.1263-1272
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    • 2008
  • Let T and S be bounded linear operators on Banach spaces X and y, respectively. A linear map A : X ${\rightarrow}$ y is said to be an intertwiner if AT - SA = 0. In this paper we study the relation between local spectral properties of T and S on the assumption of AT - SA = 0. We give some example of intertwiner with T and S.

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A NOTE ON THE DISPERSION RELATION OF THE MODIFIED BOUSSINSQ EQUATIONS

  • Cho, Yong-Sik;Lee, Chang-hoon
    • Water Engineering Research
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    • v.1 no.4
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    • pp.293-298
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    • 2000
  • Optimal values of $\alpha$ characterizing the linear dispersion property in the modified Boussinesq equations are determined by minimizing the combined relative errors of the phase and group velocities. The value of $\alpha$ is fixed in previous studies, whereas it is varying in the present study. The phase and group velocities are calculated by using variable $\alpha$ and compared to those of the linear Stokes wave theory and previous studies. It is found that the present study produces the best match to the linear Stokes theory.

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An Analysis of Elementary School Students' Understanding of Functional Relationships (초등학교 2, 4, 6학년 학생들의 함수적 관계 이해 실태 조사)

  • Choi, Ji-Young;Pang, Jeong-Suk
    • School Mathematics
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    • v.14 no.3
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    • pp.275-296
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    • 2012
  • This study investigated elementary school students' understanding of basic functional relationships. It analyzed the written responses from a total of 2087 students of second, fourth, and sixth graders using tests that examined their understanding of five types of functional relationships. The results of this study showed that students tended to be more successful as their grades went up with regard to all the problem types. There were statistically differences among the three grade levels. Even lower graders were quite successful in dealing with additive relation, direct proportion, and inverse proportion. However the items dealing with square relation and linear relation were difficult even to sixth graders. It was common that students were good at completing the table by looking for a pattern from the given numbers but that they had difficulties in anticipating the value of 'y' when the value of 'x' is given either as a big number or as a symbol. Given these results, this paper includes issues and implications on how to foster functional thinking ability at the elementary school.

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Acoustic Source Tracker Based on Pseudo-Linear DOA Estimator for Autonomous Robots (자율이동로봇 이동음원 추적센서 개발을 위한 의사선형 도래각 추정기법)

  • Lim, Jae-Il;Ra, Won-Sang
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1788-1789
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    • 2011
  • In order to develop a one-axis gimbaled acoustic source tracker for mobile robots, a pseudo-linear direction of arrival(DOA) estimator is proposed using a linear ultrasonic sensor array. Under the assumption that the sensor measurement errors are negligible, a linear measurement model is derived using the linear prediction relation of the received sinusoidal acoustic signals. Applying the Kalman filtering technique for this model, the linear recursive DOA estimator is designed. For its linear recursive filter structure, it is preferable for real-time implementation on a commercial DSP. Through the experiments, the effectiveness of the suggested method is demonstrated.

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