• Title/Summary/Keyword: Potential theory

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Super-Cavitating Flow Problems about Two-Dimensional Symmetric Strut (2차원 대칭 스트럿 주위의 초월 공동 유동 문제의 해석)

  • Y.G.,Kim;C.S.,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.4
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    • pp.15-26
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    • 1990
  • This paper describes a potential-baoed panel method formulated for the analysis cf a supercavitating two-dimensional symmetri strut. The method employs normal dipoles and sources distributed on the foil and cavity surfaces to represent the potential flow around the cavitating hydrofoil. The kinematic boundary condition on the wetted portion of the foil surface is satisfied by requiring that the total potential vanish in the fictitious inner flow region of the foil, and the dynamic boundary condition on the cavity surface is satisfied by requiring that the potential vary linearly, i.e., the tangential velocity be constant. Green's theorem then results in a potential-based integral equation rather than the usual velocity-based formulation of Hess & Smith type, With the singularities distributed on the exact hydrofoil surface, the pressure distributions are predicted with improved accuracy compared to those of the linearized lifting surface theory, especially near the leading edge. The theory then predicts the cavity shape and cavitation number for an assumed cavity length. To improve the accuracy, the sources and dipoles on the cavity surface are moved to the newly computed cavity surface, where the boundary conditions are satisfied again. This iteration process is repeated until the results are converged.

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Suggestion of New Method for the Prediction of Shock Vibration (충격진동 예측방법에 관한 새로운 방법 제안)

  • Cho, Kyu-Yong;Kang, Choo-Won;Go, Jin-Seok
    • Explosives and Blasting
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    • v.26 no.1
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    • pp.15-21
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    • 2008
  • In case of estimating the shocking vibration during the blasting demolitions, the weight and falling height of the structure, that is a potential energy, had been considered. But, this study presented a new equation which used the impulse concerning a falling weight instead of potential energy as a method of predicting the shock vibration. In this experiment, the data of the impulse were compared with the data of the potential energy by performing the free-fall, and all data were comparatively analyzed by the regression analysis method. Also, the method of the superposition theory, which is calculated by the diminution ratio according to distance, the free-fall difference according to height, and the time giving the shock to the ground according to the breakdown pattern, was compared with the previous vibration data occurring from the blasting demolitions in the same conditions. As a result, this study suggests that the impulse and the method of superposition theory be applied as a method of predicting the shocking vibration. Therefore, these results could be expected to estimate the shocking vibration more accurately than the previous method.

ELLIPTIC BOUNDARY VALUE PROBLEM WITH TWO SINGULARITIES

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
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    • v.26 no.1
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    • pp.9-21
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    • 2018
  • We investigate existence and multiplicity of the solutions for elliptic boundary value problem with two singularities. We obtain one theorem which shows that there exists at least one nontrivial weak solution under some conditions on which the corresponding functional of the problem satisfies the Palais-Smale condition. We obtain this result by variational method and critical point theory.

Density Functional Theory of PTCDA Adsorption on Si(111)In-8×8 at Room Temperature

  • Hyeon, Jeong-Min
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.475-477
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    • 2014
  • Self-assembly of the molecular system of perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride (PTCDA) is of such potential importance for organic semiconductor devices that PTCDA molecule on a variety of substrates has been extensively studied. Therefore we studied the density of states (DOS), the charge densities, and intermolacular bond lengths for PTCDA, and investigated PTCDA absorptioni sites on Si(111)In-$8{\times}8$ at room temperature using the density functional theory calculations.

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The Context Change Potential of Questions and their Foci

  • Hong, Min-Pyo
    • Language and Information
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    • v.1
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    • pp.181-225
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    • 1997
  • The semantic and pragmatic effect of inerrogative illocutionary operator is analyzed in a dynamic setting in the framework of structured meaning representation with respect to the dialogue participants' shared common ground. I propose a framework for an optinal interpretation of focus phrases in terrogatives share the essential properties of focus in general, namely that they introduce alternatives to be taken advantage of by relevant focus-sensitive operators. The theory makes an interesting prediction on the distribution and interpretation of double questions in which one question gets modified by another. A further extention of the theory is spelled out to account for other non-assertional illocutionary operators like imperatives and their foci.

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The Study of Wavelet Theory for System Identifications (웨이브렛과 유전 알고리즘을 이용한 시스템 근사화)

  • Lee, Young-Seog;Kim, Dong-Ok;Seo, Bo-Hyeok
    • Proceedings of the KIEE Conference
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    • 1998.07b
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    • pp.638-640
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    • 1998
  • This paper discusses approximation modelling of discrete-time linear time-varying system(LTVS). The wavelet theory and genetic algorithm are considered as a tool for representing and approximating a LTVS. The joint time-frequency properties of wave analysis are appropriate for describing the LTVS. Simulation results is included to illustrate the potential application of the technique.

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The Calculation of Hugoniot Adiabatics and Viscosity of Shock Compressed Water

  • Baik, Dae-Hyun;Jhon, Mu-Shik;Yoon, Byoung-Jip
    • Bulletin of the Korean Chemical Society
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    • v.7 no.4
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    • pp.293-296
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    • 1986
  • The Hugoniot adiabatics and viscosity of shock compressed water have been calculated by applying the significant structure theory of water. To consider the effects of pressure and temperature, the sublimation energy has been expressed by the spherically averaged Stillinger-Rahman ST2 potential. Good agreements between theory and experiment are obtained in the whole extreme ranges of shock wave condition up to 100 GPa (lMbar).

The modern Chinese literature and Freudian psychoanalysis - Focuing acceptance of the Freud's theory psychoanalysis on Lu xun and Guo Mo ruo (중국 신문학 초기의 프로이드 정신분석학 수용 - 루쉰(魯迅)과 궈모뤄(郭沫若)의 프로이드 정신분석학 이론 수용을 중심으로)

  • Ko, hae-kyung
    • Cross-Cultural Studies
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    • v.37
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    • pp.81-107
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    • 2014
  • Freud's' discovery of the unconscious' is a great revolution. Because of this, human beings were able to get the opportunity to look into their inner than honest. Lu Xun and Guo Mo Ruo a pair of realism and romanticism literature representative of Chinese modern literature writers. They then absorb the psychoanalytic theory o Freud along with other Western zeitgeist, introduce them widely inliterary theory and creative practice, which was again. Lu Xun was reflected in the human world of the unconscious Freud uncovered on the basis of strict realism literary spirit, Guo Mo Ruo is in accordance with the romantic literary time for the purpose of 'art for art' depicting a man's inner psychological well did. Although Freud spirit they claim to social and literary artistry of literature based on different yarns in the Acceptance of analytical theory, has the characteristics of a common sentiment analysis method to express and describe the unconscious human potential. 5.4 When Lu Xun and Guo Mo Ruo China Journalism writers, including Freud's psychoanalytic theory has embraced the Enlightenment and the old feudal society was a major contribution to want to read exactly what the human inner hearing. Chinese modern literature writers have to accept sometimes positive, sometimes accepting the psychoanalytic theory was intellectually sharp criticism, which could be a great instrument in time to the 5.4 Enlightenment and psychological fiction novel further development.

FE modeling for geometrically nonlinear analysis of laminated plates using a new plate theory

  • Bhaskar, Dhiraj P.;Thakur, Ajaykumar G.
    • Advances in aircraft and spacecraft science
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    • v.6 no.5
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    • pp.409-426
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    • 2019
  • The aim of the present work is to study the nonlinear behavior of the laminated composite plates under transverse sinusoidal loading using a new inverse trigonometric shear deformation theory, where geometric nonlinearity in the Von-Karman sense is taken into account. In the present theory, in-plane displacements use an inverse trigonometric shape function to account the effect of transverse shear deformation. The theory satisfies the traction free boundary conditions and violates the need of shear correction factor. The governing equations of equilibrium and boundary conditions associated with present theory are obtained by using the principle of minimum potential energy. These governing equations are solved by eight nodded serendipity element having five degree of freedom per node. A square laminated composite plate is considered for the geometrically linear and nonlinear formulation. The numerical results are obtained for central deflections, in-plane stresses and transverse shear stresses. Finite element Codes are developed using MATLAB. The present results are compared with previously published results. It is concluded that the geometrically linear and nonlinear response of laminated composite plates predicted by using the present inverse trigonometric shape function is in excellent agreement with previously published results.

Partition Function of Electrons in Liquid Metals

  • Zhang, Hwe-Ik
    • Nuclear Engineering and Technology
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    • v.5 no.2
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    • pp.77-82
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    • 1973
  • A method of obtaining the partition function for a system of electrons is developed by defining a new density matrix, in which the Fermi statistics is explicitly incorporated. The corresponding Bloch equation is formulated and a practical method of solving the equation is obtained for weak potential. This theory is applied to structurally disordered ststems which might be reasonable models for liquid metals.

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