• 제목/요약/키워드: and K-theory

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FIXED POINT THEORY FOR PERMISSIBLE MAPS VIA INDEX THEORY

  • Balaj, Mircea;Cho, Yeol-Je;O'Regan, Donal
    • East Asian mathematical journal
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    • 제24권1호
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    • pp.97-103
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    • 2008
  • New fixed point theorems for permissible maps between $Fr{\acute{e}}chet$ spaces are presented. The proof relies on index theory developed by Dzedzej and on viewing a $Fr{\acute{e}}chet$ space as the projective limit of a sequence of Banach spaces.

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화타상한(華佗傷寒)에 관(關)한 소고(小考) (A Study of Huatuo's Shang-han (Cold Damage) Theory)

  • 강민휘;이병욱;김기욱
    • 한국의사학회지
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    • 제31권1호
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    • pp.71-87
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    • 2018
  • This study investigated Hua Tuo's Shang-han theory, which precedes the period of Zhang Zhong Jing's Shang-han theory, and considers the relationship between the two approaches. Researchers compared terminology and language of Hua Tuo's Shang-han theory as published in Theory in Qian Jin Yao Fang and Wai Tai Mi Yao, with Zhang Zhong Jing's Shang-han theory. In Hua Tuo's theory, Shang-han involves pathogenic invasion of the body surface, where the pathogen transforms to 6 different stages, Pi (皮), Fu (膚), Ji (肌), Xiong (胸), Fu (腹), Wei (胃). Among these, the stage sof Pi (皮), Fu (膚), Ji (肌) can be considered as exterior syndrome (表證). Those that invade the lower chest can be considered as lower chest disease, and those that violate the abdomen or stomach can be considered as Interior heat excess syndrome (裏熱實證). Stomach heat excess syndrome (胃中實熱證) is the most severe and is similar to septicaemia or bubonic plague. Hua Tuo's treatment used three methods which are 汗 (perspiration), 吐 (emesis), 下 (purgation). In the case of Phlegm syndrome (痰?證), HuoTuo's theory was similar to Zhang Zhong Jing's Shang-han exterior syndrome (傷寒表證) and therefore used Zhuling-powder (猪?散). In the case of deficiency hot flush Syndrome (虛煩證) in Shang-han disease, HuoTuo uses ZhuYe-decoction (竹葉湯), of which the drug contents is the same as Zhang Zhong Jing's ZhuYeShiGao-decoction (竹葉石膏湯), which was used for the same condition.

비선형이론에 의한 Supercavitation 익렬의 유동해석 (The Flow Analysis of Supercavitating Cascade by Nonlinear Theory)

  • 박이동;황윤
    • 태양에너지
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    • 제17권1호
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    • pp.35-46
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    • 1997
  • In this study comparison of experiment results with the computed results of linear theory and nonlinear theory using singularity method was obtainable. Specially singularity points like sources and vortexes on hydrofoil and freestreamline were distributed to analyze two dimensional flow field of supercavitating cascade using nonlinear theory, and governing equations of flow field were derived and hydraulic characteristics of cascade were calculated by numerical analysis of the governing equations. The results compared linear theory and nonlinear theory with the experiment results of the study are as follows: The tolerances of nonlinear theory were larger than those of linear theory in case of ${\alpha}<10^{\circ}$. Moreover the computational range of attack angles could be expanded from ${\alpha}=10^{\circ}$ to ${\alpha}=25^{\circ}$, the flow field of supercavitating cascade could be analyzed in the condition which the wake thickness and the length of cavity are a variable. The shapes of cavity were changed sensitively according to various variable such as attack angles, pitches and wake thickness, and the pressure distribution of hydrofoil surface was identical almost disregarding wake thickness but changed largely according to attack angle and the length of cavity. Lift coefficient and drag coefficient were reduced according to increasing of wake thickness but the influences of wake thickness were very little in the situation of small pitch and long cavity.

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Interpretation of coefficient of consolidation from CRS test results

  • Jia, Rui;Chai, Jinchun;Hino, Takenori
    • Geomechanics and Engineering
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    • 제5권1호
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    • pp.57-70
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    • 2013
  • Constant rate of strain (CRS) consolidation tests were conducted for undisturbed Ariake clay samples from three boreholes in Saga Plain of Kyushu Island, Japan. The coefficients of consolidation ($c_{\nu}$) were interpreted from the CRS test results by small- and large-strain theory. Large-strain theory was found to interpret smaller $c_{\nu}$ values and less strain rate effect on $c_{\nu}$ than that by small-strain theory. Comparing the theoretical strain distributions within a soil specimen to those obtained by numerical simulation shows that the small-strain theory can be used only for the dimensionless parameter $c_{\nu}/\dot{\varepsilon}H_0^2{\geq}50$ (where $\dot{\varepsilon}$ is strain rate and $H_0$ is the specimen height), and the large-strain theory can be used for a larger range of strain rates. Applying the criterion to undisturbed Ariake clay with a $c_{\nu}$ value of about $1{\times}10^{-7}\;m^2/s$, it is suggested that the large-strain theory should be adopted for calculating the $c_{\nu}$ value when $\dot{\varepsilon}$ > 0.03%/min.

Thermal stability of functionally graded sandwich plates using a simple shear deformation theory

  • Bouderba, Bachir;Houari, Mohammed Sid Ahmed;Tounsi, Abdelouahed;Mahmoud, S.R.
    • Structural Engineering and Mechanics
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    • 제58권3호
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    • pp.397-422
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    • 2016
  • In the present work, a simple first-order shear deformation theory is developed and validated for a variety of numerical examples of the thermal buckling response of functionally graded sandwich plates with various boundary conditions. Contrary to the conventional first-order shear deformation theory, the present first-order shear deformation theory involves only four unknowns and has strong similarities with the classical plate theory in many aspects such as governing equations of motion, and stress resultant expressions. Material properties and thermal expansion coefficient of the sandwich plate faces are assumed to be graded in the thickness direction according to a simple power-law distribution in terms of the volume fractions of the constituents. The core layer is still homogeneous and made of an isotropic material. The thermal loads are considered as uniform, linear and non-linear temperature rises within the thickness direction. The results reveal that the volume fraction index, loading type and functionally graded layers thickness have significant influence on the thermal buckling of functionally graded sandwich plates. Moreover, numerical results prove that the present simple first-order shear deformation theory can achieve the same accuracy of the existing conventional first-order shear deformation theory which has more number of unknowns.

Wave propagation in a microbeam based on the modified couple stress theory

  • Kocaturk, Turgut;Akbas, Seref Doguscan
    • Structural Engineering and Mechanics
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    • 제46권3호
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    • pp.417-431
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    • 2013
  • This paper presents responses of the free end of a cantilever micro beam under the effect of an impact force based on the modified couple stress theory. The beam is excited by a transverse triangular force impulse modulated by a harmonic motion. The Kelvin-Voigt model for the material of the beam is used. The considered problem is investigated within the Bernoulli-Euler beam theory by using energy based finite element method. The system of equations of motion is derived by using Lagrange's equations. The obtained system of linear differential equations is reduced to a linear algebraic equation system and solved in the time domain by using Newmark average acceleration method. In the study, the difference of the modified couple stress theory and the classical beam theory is investigated for the wave propagation. A few of the obtained results are compared with the previously published results. The influences of the material length scale parameter on the wave propagation are investigated in detail. It is clearly seen from the results that the classical beam theory based on the modified couple stress theory must be used instead of the classical theory for small values of beam height.

인간과학적 배경과 Watson의 돌봄이론 (Human science paradigm and Watson's theory of human caring)

  • 한선희;남은숙
    • 한국간호교육학회지
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    • 제3권2호
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    • pp.246-254
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    • 1997
  • Nursing have been caught between the paradigm of medical science with a body part view of a person and the paradigm of medical science with an emphasis on unsurpassable control, rigor, objectivism, and neutrality of value. But it is inappropriate to apply impersonal, objective model of science for the personal unique and gestalt experiences of nursing phenomena. Jean Watson proposed a theory of human caring based on human science paradigm to explain human phenomena. This study reviewed the theory of nursing by Jean Watson and the researches based on Waton's theory. In this study the researcher examined the philosophical back ground, value system and key concepts of Watson's theory Watson's perspective of person and human existence includes humanistic and phenomenological characteristics. She also emphasized nurse-patient relationship as an intersubjective(transpersonal) caring relationship. Examination of the studies based on Watson's theory consistantly revealed Watson's theory of human caring based on the human science paradigm is more appropriate than traditional medical science paradigm for explaining nursing phenomena. For the purpose of refining the theory and promoting usefulness of the theory, it would be desirable to test the theory to the nursing phenomena and to apply the theory to practice and education.

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A trigonometric four variable plate theory for free vibration of rectangular composite plates with patch mass

  • Draiche, Kada;Tounsi, Abdelouahed;Khalfi, Y.
    • Steel and Composite Structures
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    • 제17권1호
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    • pp.69-81
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    • 2014
  • The novelty of this paper is the use of trigonometric four variable plate theory for free vibration analysis of laminated rectangular plate supporting a localized patch mass. By dividing the transverse displacement into bending and shear parts, the number of unknowns and governing equations of the present theory is reduced, and hence, makes it simple to use. The Hamilton's Principle, using trigonometric shear deformation theory, is applied to simply support rectangular plates. Numerical examples are presented to show the effects of geometrical parameters such as aspect ratio of the plate, size and location of the patch mass on natural frequencies of laminated composite plates. It can be concluded that the proposed theory is accurate and simple in solving the free vibration behavior of laminated rectangular plate supporting a localized patch mass.

An inverse hyperbolic theory for FG beams resting on Winkler-Pasternak elastic foundation

  • Sayyad, Atteshamuddin S.;Ghugal, Yuwaraj M.
    • Advances in aircraft and spacecraft science
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    • 제5권6호
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    • pp.671-689
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    • 2018
  • Bending, buckling and free vibration responses of functionally graded (FG) higher-order beams resting on two parameter (Winkler-Pasternak) elastic foundation are studied using a new inverse hyperbolic beam theory. The material properties of the beam are graded along the thickness direction according to the power-law distribution. In the present theory, the axial displacement accounts for an inverse hyperbolic distribution, and the transverse shear stress satisfies the traction-free boundary conditions on the top and bottom surfaces of the beams. Hamilton's principle is employed to derive the governing equations of motion. Navier type analytical solutions are obtained for the bending, bucking and vibration problems. Numerical results are obtained to investigate the effects of power-law index, length-to-thickness ratio and foundation parameter on the displacements, stresses, critical buckling loads and frequencies. Numerical results by using parabolic beam theory of Reddy and first-order beam theory of Timoshenko are specially generated for comparison of present results and found in excellent agreement with each other.

변칙 사례에 대한 학생들의 반응 유형 (Types of Students' Responses to Anomalous Data)

  • 노태희;임희연;강석진
    • 한국과학교육학회지
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    • 제20권2호
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    • pp.288-296
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    • 2000
  • 본 연구에서는 변칙 사례에 대한 학생들의 반응 유형과 특성을 조사하였다. 학생들의 응답 분류 기준은 '변칙 사례의 타당성 인정', '변칙 사례와 초기 이론 사이의 불일치성 인정', 그리고 '초기 이론에 대한 확신의 변화' 등이었다. 분류 결과, 거부, 재해석, 배제, 판단 불가, 주변 이론의 변화, 신념의 일부 변화, 이론 변화 등 7가지 반응 유형을 얻었다. 초기 이론에 대한 무조건적인 신뢰나 실험 방법의 정확성에 대한 의심이 변칙 사례를 거부하는 주된 원인이었다. 학생들은 변칙 사례와 초기 이론에 관련된 실험 과정은 무시하고 실험 결과의 유사성에 더 주목했기 때문에 불일치성을 인정하지 않았다.

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