• 제목/요약/키워드: Lattice theory

검색결과 164건 처리시간 0.022초

Nonlinear Localized Modes in Photonic Crystals

  • Park, Q-Han
    • Journal of the Optical Society of Korea
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    • 제6권3호
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    • pp.96-99
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    • 2002
  • We give a brief overview of nonlinear localized modes in photonic crystals. We explain how photonic crystals can potentially be important in making small scale active devices which operate in an all optical way. Two models to approach nonlinear photonic crystals, the coupled mode theory and the discrete lattice theory using a Green's function, are explained.

트러스 벽면과 미세격자 트러스로 구성된 정육면체 단위모델의 강성 및 강도 개발 (Development of Effective Stiffness and Effective Strength for a Truss-Wall Rectangular model combined with Micro-Lattice Truss)

  • 최정호
    • 한국산업융합학회 논문집
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    • 제19권3호
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    • pp.133-143
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    • 2016
  • The objective in here is to find the density, stiffness, and strength of truss-wall rectangular (TWR) model which is combined with lattice truss (MLT) inside space. The TWR unit-cell model is defined as a unit cell originated from a solid-wall rectangular (SWR) model and it has an empty space inside. Thus, the empty space inside of the TWR is filled with lattice truss model defined as TWR-MLT. The ideal solutions derived of TWR-MLT are based on TWR with MLT model and it has developed by Gibson-Ashby's theory. To validate the ideal solutions of the TWR-MLT, ABAQUS software is applied to predict the density, strength, and stiffness, and then each of them are compared with the Gibson-Ashby's ideal solution as a log-log scale. Applied material property is stainless steel 304 because of cost effectiveness and easy to get around. For the analysis, SWR and TWR-MLT models are 1mm, 2mm, and 3mm truss diameter separately within a fixed 20mm opening width. In conclusion, the relative Young's modulus and relative yield strength of the TWR-MLT unit model is reasonably matched to the ideal expectations of the Gibson-Ashby's theory. In nearby future, TWR-MLT model can be verified by advanced technologies such as 3D printing skills.t.

유기플라스틱 결정체의 PMR 연구 (제 1 보). 피발산 (PMR in Organic Plastic Crystals (I). Pivalic Acid)

  • 최종권;잔 그레함
    • 대한화학회지
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    • 제19권3호
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    • pp.149-155
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    • 1975
  • 플라스틱 결정체인 피발산의 temperature-dependent wide-line NMR line width, second monent 및 spin-lattice relaxation times 의 결과는 이 결정체의 특이한 운동학적 성질 및 수소결합에 기인된 것으로 해석된다. 이 분자의 운동학적 성질은 $C_3-C_3'$ reorientation 및 self-diffusion 으로 구성 되었음을 확인했다. Wide-line NMR 연구결과는 또한 Pople-Karasz 융해설과 비교검토되었고, 이 이론과의 차이점은 피발산의 수소결합에 기인되었음을 알아냈다.

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Г-DEVIATION AND LOCALIZATION

  • Albu, Toma;Teply, Mark L.
    • 대한수학회지
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    • 제38권5호
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    • pp.937-954
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    • 2001
  • This paper is a natural continuation of [2], [3], [4] and [5]. Localization techniques for modular lattices are developed. These techniques are applied to study liftings of linear order types from quotient lattices and to find Г-dense sets in certain lattices without Г-deviation in the sense of [4], where Г is a set of indecomposable linear order types.

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유기절연물의 전기전도와 절연파괴 (Electric conduction and breakdown of organic insulator)

  • 성영권
    • 전기의세계
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    • 제16권4호
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    • pp.11-16
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    • 1967
  • A physical analysis is applied to the measured phenomena of aromatic organic compounds under the uniform electric field of 0.1MV/cm through 1.5MV/cm, when they are irradiated or non-irradiated respectively. Upon the observations about irradiation effects, space charge effects and their temperature dependance, the conditions of lattice defects act conspicuously on electric conductrivity, photo conductivity and dielectric breakdown. Although the qualitative agreement with Frohlich's high energy criterion theory for the above mechanisms is poor, it is concluded that the phenomena of aromatic compounds may possibly be due to the effect of lattice defects or impurity centers generated by .gamma.-ray irradiations.

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ON FUZZY CLOSEDNESS IN LATTICE IMPLICATION ALGEBRAS

  • Jun, Young-Bae;Song, Seok-Zun;Roh, Eun-Hwan
    • Journal of applied mathematics & informatics
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    • 제11권1_2호
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    • pp.341-355
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    • 2003
  • The fuzzification of ${\bigotimes}-closed$ set is considered, and its basic properties we investigated. Characterizations of fuazzy ${\bigotimes}-closed$ set we given. Using a collection of ${\bigotimes}-closed$ sets with additional conditions, a fuzzy ${\bigotimes}-closed$ set is stated. The theory of fuzzy topological ${\bigotimes}-closed$ sets is discussed.

Topological Approach to the Rubber Elasticity of Polymer Networks

  • 손정모;박형숙
    • Bulletin of the Korean Chemical Society
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    • 제10권1호
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    • pp.84-96
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    • 1989
  • Applying the topological theory of rubber elasticity which was suggested by K. Iwata to the newly devised body-centered cubic lattice model, the authors calculated the values of four terms of the free energy to form polymer networks. Finding the projection matrix of the BCL model, and comparing this with the values of the simple cubic lattice (abbreviated to SCL hereafter) model of K. Iwata, the authors obtained the stress versus strain curves and found that the curves are in good agreement with the experimental results of poly(dimethyl siloxane) networks.

격자볼츠만법을 이용한 자유수면 거동 특성 연구 (Study on the Free Surface Behavior Using the Lattice Boltzmann Method)

  • 정노택
    • 한국해양환경ㆍ에너지학회지
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    • 제16권4호
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    • pp.255-262
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    • 2013
  • 본 연구에서는 연속체 이론을 배경으로 하며 일반적으로 많이 사용되는 Navire-Stokes방정식이 아닌 입자의 확률분포를 배경으로 하는 Boltzmann 방정식을 이용하여 자유수면을 포함하는 유동을 해석하는 전산시뮬레이션 코드를 개발하였다. 댐 붕괴시뮬레이션에 적용하여 코드의 검증을 수행하였으며, 기존의 실험 및 계산결과와 비교함과 동시에 격자볼츠만 시뮬레이션의 특성을 분석하였다. 공학적 응용을 위해서 임의 형상의 물체가 존재시에 자유수면 시뮬레이션도 수행하였다.

Thermal Behavior of Critical Micelle Concentration from the Standpoint of Flory-Huggins Model

  • Lim, Kyung-Hee
    • Bulletin of the Korean Chemical Society
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    • 제30권9호
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    • pp.2001-2006
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    • 2009
  • Temperature dependence of the critical micelle concentration (CMC), $x_{CMC}$, in micellization can be described by ln $x_{CMC}$ = A + BT + C lnT + D/T, which has been derived statistical-mechanically. Here A, B, C, and D are fitting parameters. The equation fits the CMC data better than conventionally used polynomial equations of temperature. Moreover, it yields the unique(exponent) value of 2 when the CMC is expressed in a power-law form. This finding is quite significant, because it may point to the universality of the thermal behavior of CMC. Hence, in this article, the nature of the equation ln $x_{CMC}$ = A + BT + C lnT + D/T is examined from a lattice-theory point of view through the Flory-Huggins model. It is found that a linear behavior of heat capacity change of micellization is responsible for the CMC equation of temperature.

Palladium의 Embedded Atom Method 개발 (The Embedded Atom Method Analysis of the Palldium)

  • 정영관;김경훈;김세웅;이성희;이근진;박규섭
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.652-655
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    • 2002
  • The embedded atom method based on the density functional theory is used for calculating ground state properties of realistic metal systems. In this paper, we had corrected constitutive formulae and parameters on the palladium for the purpose of doing Embedded Atom Method analysis. And then we have computed the properties of the palladium on the fundamental scale of the atomic structure. In result, simulated ground state properties, such as the lattice constant, elastics constants and the sublimation energy, show good agreement with Daw's simulation data and with experimental data.

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