• 제목/요약/키워드: classical theory

검색결과 909건 처리시간 0.02초

The Significant Structure Theory of Liquids Applied to Homogeneous Nucleation Theory

  • Jong-Myung Lee;Mu-Shik Jhon
    • Bulletin of the Korean Chemical Society
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    • 제1권1호
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    • pp.26-28
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    • 1980
  • The surface tensions, the chemical potentials and the densities of various liquids such as argon, nitrogen, helium, ammonia, and water are calculated using the significant structure theory of liquids. And using these calculated values, the critical supersaturation ratios and the radii of the above materials are determind according to the classical Becker-Doring and the revised Lothe-Pound theories. The results are compared with the experimental values and well agreed with the available experimental data.

고분자 용액에서의 기포 형성 (Bubble Nucleation in Polymer Solutions)

  • 강성린;김기영;곽호영
    • 폴리머
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    • 제28권1호
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    • pp.51-58
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    • 2004
  • 탄성체 (가교된 고분자) 가스가 용해된 고분자 또는 유기 용매에 용해된 고분자 용액에서 기포 생성을 예측하기 위하여 균일한 기포 생성은 고전적인 이론에서의 임계 기포의 생성이 아닌 임계 뭉치의 생성을 통하여 이루어진다는 분자 뭉치 이론을 적용하였다. 또한 탄성체나 고분자 내에서 기포가 생성하는 경우 임계 기포가 극복해야 할 탄성 에너지를 고려하였다. 대략 $10^{8}$$10^{12}$개에 달하는 분자 뭉치 이론에 의해 계산된 단위 부피당 생성된 기포 수는 실험치와 잘 일치하였다.

필라멘트 와인딩 공법에 의한 소형 선박용 복합재료 축 설계를 위한 응력해석에 관한 연구 (A Study on Stress Analysis for Design of Composites Shaft on Small Ship by Filament Winding Process)

  • 배창원;임철문;왕지석;김윤해
    • Journal of Advanced Marine Engineering and Technology
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    • 제25권3호
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    • pp.617-622
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    • 2001
  • The purpose of this study is to design and the analyze the stress of composited shaft which is wound by filament winding method. The composites shaft has high strength and reduction in weight compared to metal shaft. The classical laminate plate theory(CLT) was used fro analysis the stress, and for structure design. In order to replace metal shaft by composites shaft, the diameter of shaft was determined to $\phi$ 40. The ration of diameter was determined to 0.4 for torsional moment with CLT. In this result of analyzing the stress, composites shaft was safe $30^{\circ}~60^{\circ}$C of winding angle, and was fractured on $90^{\circ}$.

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유리섬유/탄소섬유 강화 비대칭 하이브리드 복합재의 스프링 백 예측 (Prediction of Spring-back for GFR/CFR Unsymmetric Hybrid Composites)

  • 정우균;안성훈;원명식
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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    • pp.158-161
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    • 2005
  • The fiber-reinforced composite materials have been advanced for various applications because of its excellent mechanical and electromagnetic properties. On their manufacturing processes, however, thermo-curing inherently produces the undesired thermal deformation mainly from temperature drop from the process temperature to the room temperature, so called spring-back. The spring-back must be removed to keep the precision of designed shape. In this research, the spring-back of {glass fiber / epoxy}+{carbon fiber / epoxy} unsymmetric hybrid composites were predicted using Classical Lamination Theory (CLT), and compared with the experimental data. Additionally, using finite element analysis (ANSYS), the predicted data and experimental data were compared. The predicted values by CLT and ANSYS were well matched with experimental data.

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Rough Set-based Incremental Inductive Learning Algorithm Theory and Applications

  • Bang, Won-Chul;Z. Zenn Bien
    • 한국지능시스템학회논문지
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    • 제11권7호
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    • pp.666-674
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    • 2001
  • Classical methods to find a minimal set of rules based on the rough set theory are known to be ineffective in dealing with new instances added to the universe. This paper introduces an inductive learning algorithm for incrementally retrieving a minimal set of rules from a given decision table. Then, the algorithm is validated via simulations with two sets of data, in comparison with a classical non-incremental algorithm. The simulation results show that the proposed algorithm is effective in dealing with new instances, especially in practical use.

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운동치료의 변화와 발전 (Change and Development of Therapeutic Exercise)

  • 배성수;김승준;이근희
    • The Journal of Korean Physical Therapy
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    • 제13권3호
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    • pp.751-760
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    • 2001
  • Therapeutic exercise had developed with human being. It depend upon development of physiology, anatomy, kinesiology and biomechanics. There are two categories in therapeutic exorcise. One is classical therapeutic exercise which is a activity of one muscle group, one axis and one plane motion. It is ROM, FRE. osteokinematics, arthrokinematics. Another is neurophysiological approach which is multi muscle group, multi axis and plane exercise. It is PNF and Bobath that start from 1940 to early 1950. Classical therapeutic exorcise develop from ROM to osteokinematics and arthrokinematics. It is foundation of the joint mobilization and orthopaedic manual physical therapy. Neurophysiological therapeutic approaching has more theory and skills than before. Bobath methods had changed from reflex-inhibiting posture to key points of control and added the theory of musculoskeletal, biomechanics, motor behaviour and cognition. We call it motor control.

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고전 적층이론에 의한 섬유금속적층판의 기계적 거동 연구 (Study on the Mechanical Behavior of Fiber Metal Laminates Using Classical Lamination Theory)

  • 노희석;최흥섭;강길호;하민수
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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    • pp.37-41
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    • 2003
  • In this study the mechanical behaviors of fiber metal laminates (FML) such as ARALL, GLARE and CARE which are recently developed as new structural materials and known to have excellent fatigue resistant characteristics while with relatively low densities compared to the conventional aluminum materials, are considered through the classical lamination theory. The mechanical properties such as elastic moduli, thermal expansion coefficients and hygro-thermally induced residual stresses in the fiber metal laminates are obtained and compared each other. Also load carrying mechanism between metal sheets and composite layers in the FML are considered.

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유한한 대역폭을 가지는 통신 채널에서의 상태 추정값에 대한 분산 해석 (Variance Analysis for State Estimation In Communication Channel with Finite Bandwidth)

  • 황태현;최재원
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집A
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    • pp.693-698
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    • 2000
  • Aspects of classical information theory, such as rate distortion theory, investigate how to encode and decode information from an independently identically distributed source so that the asymptotic distortion rate between the source and its quantized representation is minimized. However, in most natural dynamics, the source state is highly corrupted by disturbances, and the measurement contains the noise. In recent coder-estimator sequence is developed for state estimation problem based on observations transmitted with finite communication capacity constraints. Unlike classical estimation problems where the observation is a continuous process corrupted by additive noises, the condition is that the observations must be coded and transmitted over a digital communication channel with finite capacity. However, coder-estimator sequence does not provide such a quantitative analysis as a variance for estimation error. In this paper, under the assumption that the estimation error is Gaussian distribution, a variance for coder-estimation sequence is proposed and its fitness is evaluated through simulations with a simple example.

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A unified formulation for static behavior of nonlocal curved beams

  • Tufekci, Ekrem;Aya, Serhan A.;Oldac, Olcay
    • Structural Engineering and Mechanics
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    • 제59권3호
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    • pp.475-502
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    • 2016
  • Nanobeams are widely used as a structural element for nanodevices and nanomachines. The development of nano-sized machines depends on proper understanding of mechanical behavior of these nano-sized beam elements. Small length scales such as lattice spacing between atoms, surface properties, grain size etc. are need to be considered when applying any classical continuum model. In this study, Eringen's nonlocal elasticity theory is incorporated into classical beam model considering the effects of axial extension and the shear deformation to capture unique static behavior of the nanobeams under continuum mechanics theory. The governing differential equations are obtained for curved beams and solved exactly by using the initial value method. Circular uniform beam with concentrated loads are considered. The displacements, slopes and the stress resultants are obtained analytically. A detailed parametric study is conducted to examine the effect of the nonlocal parameter, mechanical loadings, opening angle, boundary conditions, and slenderness ratio on the static behavior of the nanobeam.

Exact mathematical solution for free vibration of thick laminated plates

  • Dalir, Mohammad Asadi;Shooshtari, Alireza
    • Structural Engineering and Mechanics
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    • 제56권5호
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    • pp.835-854
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    • 2015
  • In this paper, the modified form of shear deformation plate theories is proposed. First, the displacement field geometry of classical and the first order shear deformation theories are compared with each other. Using this comparison shows that there is a kinematic relation among independent variables of the first order shear deformation theory. So, the modified forms of rotation functions in shear deformation theories are proposed. Governing equations for rectangular and circular thick laminated plates, having been analyzed numerically so far, are solved by method of separation of variables. Natural frequencies and mode shapes of the plate are determined. The results of the present method are compared with those of previously published papers with good agreement obtained. Efficiency, simplicity and excellent results of this method are extensible to a wide range of similar problems. Accurate solution for governing equations of thick composite plates has been made possible for the first time.