• Title/Summary/Keyword: Potential theory

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Comparison of Potentials for Polymeric Liquids (고분자액체에 대한 포텐셜의 비교)

  • Jeong, Hae Yeong
    • Journal of the Korean Chemical Society
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    • v.46 no.6
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    • pp.545-549
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    • 2002
  • Many theories for polymeric liquids are based on the concepts of cell, hole, free volume or lattice etc. In the theories, van der Waals potential, Lennard-Jones 6-12 potential and their modified potentials are commonly used.In this work, Mie(p, 6) potential was applied to the Continuous Lattice Fluid Theory (which extends the discrete lattices of Lattice Fluid Theory to classically continuous lattices) and Dee-Walsch's Cell Theory (which modifies Flory's Equa-tion of State Theory). Both of them are known to be successful theories for polymeric liquids. Thus, PVT values chang-ing with p (the exponent in the repulsion potential) were calculated and compared with experimental values. And, calculated values of Lattice Fluid Theory, Flory's Equation of State Theory and Cho-Sanchez Theory using pertubation method were also compared. Through the calculated results, van der Waals potential, Lennard-Jones 6-12 potential and Mie(p, 6) potential for polymeric liquids were compared with each other.

Potential-based Reinforcement Learning Combined with Case-based Decision Theory (사례 기반 결정 이론을 융합한 포텐셜 기반 강화 학습)

  • Kim, Eun-Sun;Chang, Hyeong-Soo
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.12
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    • pp.978-982
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    • 2009
  • This paper proposes a potential-based reinforcement learning, called "RLs-CBDT", which combines multiple RL agents and case-base decision theory designed for decision making in uncertain environment as an expert knowledge in RL. We empirically show that RLs-CBDT converges to an optimal policy faster than pre-existing RL algorithms through a Tetris experiment.

Trajectory Planning of Multi Agent Robots for Robot Soccer Using Complex Potential (복소 포텐셜을 이용한 로봇 축구용 다개체 로봇의 경로 계획)

  • Lee, Kyunghee;Kim, Donghan;Rew, Keun-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.12
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    • pp.1073-1078
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    • 2012
  • This paper deals with the trajectory planning of multi agent robots using complex potential theory for robot soccer. The complex potential theory is introduced, then the circle theorem is used to avoid obstacles, and the vortex pair is used to make precise kicking direction of robot. Various situations of robot soccer are simulated and the effect of vortex strength and the speed of robots are discussed and the better way to avoid obstacles and to kick the precise direction is found. The feasibilities of complex potential theory to apply for the multi agent robots are successful.

Activity Coefficients and Coulombic Correction Factor for Surface Complexation Modeling

  • Rhee, In-Hyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.3 no.2
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    • pp.146-155
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    • 2002
  • Surface complexation models employ mass law equations to describe the reaction of surface functional groups with ions in the solution and also Gouy-Chapman theory to consider the electrostatic effects in the surface reactions. In current surface complexation models, however, the coulombic factors used are not wholly consistent with the Gouy-Chapman model of the surface. This study was to provide the derivation of the coulombic term usually employed and then a revised coulombic term completely consistent with Gouy-Chapman Theory. The electrical potential energy. zF${\psi}$, in current surface complexation models is not consistent with the Gouy-Chapman theory with the potential gradient close to the charged surface but with the Donnan model with the uniform potential. Even though the new coulombic factor yielded lower surface potential, it provided worse fits for acid-base titration data of the goethite suspensions.

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Computational Investigation of Seakeeping Performance of a Surfaced Submarine in Regular Waves

  • Jung, Doojin;Kim, Sanghyun
    • Journal of Ocean Engineering and Technology
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    • v.36 no.5
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    • pp.303-312
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    • 2022
  • A submarine is optimized to operate below the water surface because it spends most of its time in a submerged condition. However, the performance in free surface conditions is also important because it is unavoidable for port departure and arrival. Generally, potential flow theory is used for seakeeping analysis of a surface ship and is known for excellent numerical accuracy. In the case of a submarine, the accuracy of potential theory is high underwater but is low in free surface conditions because of the nonlinearity near the free surface area. In this study, the seakeeping performance of a Canadian Victoria Class submarine in regular waves was investigated to improve the numerical accuracy in free surface conditions by using computational fluid dynamics (CFD). The results were compared to those of model tests. In addition, the potential theory software Hydrostar developed by Bureau Veritas was also used for seakeeping performance to compare with CFD results. From the calculation results, it was found that the seakeeping analysis by using CFD gives good results compared with those of potential theory. In conclusion, seakeeping analysis based on CFD can be a good solution for estimating the seakeeping performance of submarines in free surface conditions.

Nonexistence and non-decoupling of the dissipative potential for geo-materials

  • Liu, Yuanxue;Zhang, Yu;Wu, Runze;Zhou, Jiawu;Zheng, Yingren
    • Geomechanics and Engineering
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    • v.9 no.4
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    • pp.531-545
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    • 2015
  • Two fundamental issues exist in the damage theory of geo-material based on the concept of thermodynamics: existence or nonexistence of the dissipation potential, and whether the dissipation potential could be decoupled into a damage potential and a plastic one or not. Thermodynamics theory of elastoplastic damage assumes the existence of dissipation potential, but the presence of dissipation potential is conditional. Based on the dissipation inequality in accord with the second law of thermodynamics, the sufficient and necessary conditions are given for the existence of the dissipation potential separately in total and incremental forms firstly, and proved strictly in theory. With taking advantage of the basic mechanical properties of geo-materials, the nonexistence of the dissipative potential is verified. The sufficient and necessary conditions are also given and proved for the decoupling of the dissipation potential of geo-materials in total and incremental forms. Similarly, the non-decoupling of the dissipation potential has also been proved, which indicates the dissipation potential of geo-materials in total or incremental forms could not be decoupled into a dissipative potential for plasticity and that for damage respectively. The research results for the fundamental issues in the thermodynamics theory of damage will help establish and improve the theoretic basis of elastoplastic damage constitutive model for geo-materials.

Nonexistence and non-decoupling of the dissipative potential for geo-materials

  • Liu, Yuanxue;Zhang, Yu;Wu, Runze;Zhou, Jiawu;Zheng, Yingren
    • Geomechanics and Engineering
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    • v.9 no.5
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    • pp.569-583
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    • 2015
  • Two fundamental issues exist in the damage theory of geo-material based on the concept of thermodynamics: existence or nonexistence of the dissipation potential, and whether the dissipation potential could be decoupled into a damage potential and a plastic one or not. Thermodynamics theory of elastoplastic damage assumes the existence of dissipation potential, but the presence of dissipation potential is conditional. Based on the dissipation inequality in accord with the second law of thermodynamics, the sufficient and necessary conditions are given for the existence of the dissipation potential separately in total and incremental forms firstly, and proved strictly in theory. With taking advantage of the basic mechanical properties of geo-materials, the nonexistence of the dissipative potential is verified. The sufficient and necessary conditions are also given and proved for the decoupling of the dissipation potential of geo-materials in total and incremental forms. Similarly, the non-decoupling of the dissipation potential has also been proved, which indicates the dissipation potential of geo-materials in total or incremental forms could not be decoupled into a dissipative potential for plasticity and that for damage respectively. The research results for the fundamental issues in the thermodynamics theory of damage will help establish and improve the theoretic basis of elastoplastic damage constitutive model for geo-materials.

Ionic Size Effect on the Double Layer Properties: A Modified Poisson-Boltzmann Theory

  • Lou, Ping;Lee, Jin-Yong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2553-2556
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    • 2010
  • On the basis of a simple modified Poisson-Boltzmann (SMPB) theory, taking into account the finite ionic size, the analytic expression for the effect of ionic size on the diffuse layer potential drop at negative charge densities has been given for the simple 1:1 electrolyte. It is shown that the potential drop across the diffuse layer depends on the size of the ions in the electrolyte. For a given electrolyte concentration and electrode charge density, the diffuse layer potential drop in a small ion system is smaller than that in a large ion system. It is also displayed that the diffuse layer potential drop is always less than the value of the Gouy-Chapman (GC) theory, and the deviation increases as the electrode charge density increases for a given electrolyte concentration. These theoretical results are consistent with the results of the Monte-Carlo simulation [Fawcett and Smagala, Electrochimica Acta 53, 5136 (2008)], which indicates the importance of including steric effects in modeling diffuse layer properties.

Interrelation of Yin and Yang in Action Potential of Cell Membrane (세포막 활동전압에서 음양(陰陽)의 상호관계)

  • Park, Sun Young;Kim, Ho Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.5
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    • pp.563-569
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    • 2013
  • This study was undertaken to apply the yin-yang theory in action potential. In order to apply the yin-yang theory in action potential, nature of yin and yang, interrelation of yin and yang and action potential in cell were reviewed. According to the yin-yang theory, inner cellular space corresponds to yin, but outer cellular space corresponds to yang. If we classify ions in intracellular fluid or extracellular fluid by nature of yin and yang, potassium(K+) corresponds to yang within yin(陰中之陽), protein(Pr-) corresponds to yin within yin(陰中之陰) in intracellular fluid, and sodium(Na+) corresponds to yang within yang(陽中之陽), chloride(Cl-) corresponds to yin within yang(陽中之陰) in extracellular fluid. Double donnan equilibrium and equilibrium potential were caused by intracellular anion(Pr-) and extracellular cation(Na+) are related with mutual rooting of yin and yang(陰陽互根) and opposition of yin and yang(陰陽對立). The influx and efflux of ion through cell membrane means waxing and waning of yin and yang(陰陽消長), the change of membrane potential means yin-yang conversion(陰陽轉化) during action potential.

A Relationship between Drying Shrinkage and Water Potential (콘크리트의 건조수축과 수리에너지의 상관관계)

  • 한만엽
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.10a
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    • pp.58-61
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    • 1992
  • Water potential which controls miosture movement in concrete is a kind of stress which causes concrete shrinks or expands. Therefore, there is a straightforward relationship between the water potential and the shrinkage strain. Explicit equations which show the relationships between the two parameters were derived through rational process. Two micro mechanisms among three shrinkage mechanisms were considered in the theory. Thermocouple psychrometer were embedded in a concrete slab to measure the water potential and also to find a correlation with the shrinkage. The test results prove the validity of the theory, and show the way to utilize the delived equations.

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