• 제목/요약/키워드: and K-theory

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Bending analysis of a single leaf flexure using higher-order beam theory

  • Nguyen, Nghia Huu;Lee, Dong-Yeon
    • Structural Engineering and Mechanics
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    • 제53권4호
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    • pp.781-790
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    • 2015
  • We apply higher-order beam theory to analyze the deflections and stresses of a cantilevered single leaf flexure in bending. Our equations include shear deformation and the warping effect in bending. The results are compared with Euler-Bernoulli and Timoshenko beam theory, and are verified by finite element analysis (FEA). The results show that the higher-order beam theory is in a good agreement with the FEA results, with errors of less than 10%. These results indicate that the analysis of the deflections and stresses of a single leaf flexure should consider the shear and warping effects in bending to ensure high precision mechanism design.

Mechanical and thermal stability investigation of functionally graded plates resting on elastic foundations

  • Houari, Ali;Benguediab, Mohamed;Bakora, Ahmed;Tounsi, Abdelouahed
    • Structural Engineering and Mechanics
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    • 제65권4호
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    • pp.423-434
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    • 2018
  • In present work, both the hyperbolic shear deformation theory and stress function concept are used to study the mechanical and thermal stability responses of functionally graded (FG) plates resting on elastic foundation. The accuracy of the proposed formulation is checked by comparing the computed results with those predicted by classical plate theory (CPT), first-order shear deformation theory (FSDT) and higher-order shear deformation theory (HSDT). Moreover, results demonstrate that the proposed formulation can achieve the same accuracy of the existing HSDTs which have more number of governing equations.

Design of Resonator-Coupled Wireless Power Transfer System by Use of BPF Theory

  • Awai, Ikuo;Ishida, Tetsuya
    • Journal of electromagnetic engineering and science
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    • 제10권4호
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    • pp.237-243
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    • 2010
  • A wireless power transfer system based on magnetically coupled two resonators is analysed using the filter theory. Design equations for each lumped parameter circuit components are derived. As a result, change of coupling coefficient between the resonators and/or change of load resistance are easily responded. Effect of circuit loss to the design theory is also addressed. After designing a power transfer system, a real system is constructed using spiral and loop coils. Dependence of circuit elements on their dimensions is measured in advance and used to cope with the designed element values. Simulated response by use of designed element values and measured result are compared, indicating the validity of the theory.

Esterel 기반 임베디드 소프트웨어의 신뢰성 향상을 위한 개발 기법 (A Development Methodology for Reliability Improvement of ESTEREL based Embedded Software)

  • 양진석;심재환;김진현;강인혜;최진영
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (B)
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    • pp.334-336
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    • 2005
  • 본 논문은 정형 명세 언어인 Esterel이 가지는 취약점을 보안하기 위해 Safety-Critical Aided Development Environment를 추가로 활용하여 신뢰성 있고 안전적인 임베디드 제어 소프트웨어 개발을 위한 기법을 제시하고 있다. 그 뿐만 아니라 제시한 기법을 이용하여 개발된 간단한 자동 강속 제어 소프트웨어를 인터페이스와 기능 부분에 대해서 각각 확인 및 검증을 수행한 후 임베디드 시스템인 레고 마인드 스톰으로 제작된 차량 로봇에 탑재한 후 실험을 하고, 실험을 통해 기존 개발 기법과의 차이점을 분석한다.

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"동의수세보원(東醫壽世保元)"의 병증론이 8체질론(體質論)의 형성에 미친 영향에 대한 고찰(考察) (A Study on How the Discourse on the Constitutional Symptoms and Diseases in "Donguisusebowon" Influenced the Formation of the Theory of Eight Constitution)

  • 정용재;박성식
    • 사상체질의학회지
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    • 제23권4호
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    • pp.445-457
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    • 2011
  • 1. Purpose Lee Je-Ma had continued to revise "Donguisusebowon" by adding the contents of the Symptomatic-pharmacology(病證藥理論) on Soeumin, Soyangin and Taeeumin to it from the first establishment of the old version in 1894 to 1900.(new version). This paper tries to find out the contents and meaning of the Discourse on the Constitutional Symptoms and Diseases(病證論) between the old version and new version and what the Discourse on the Constitutional Symptoms and Diseases affected the Theory of Eight Constitution created in subsequent years. 2. Methods I classified the Discourse on the Constitutional Symptoms and Diseases in "DongYiSuseBowon" into old version and new version and tried to find out the Theory of Eight morbidities(8病證論) which is the predecessor of the Theory of Eight Constitution, before reviewing their relation. 3. Conclusions 1) The Discourse on the Constitutional Symptoms and Diseases in the old version specify that the externally sensed diseases are caused by the deep sediment of nature(性) and that the internally touched diseases are caused by the violent activities of emotion(情). In addition, it said that all diseases are caused by the specific characteristics of patient's smaller internal organs(偏小之臟). But in new version, the diseases were understood through the concept Exterior, Interior, Heat and cold(表裏寒熱). The new version said that the diseases may be caused not only the specific characteristics of patient's smaller organs but also by bigger organs(偏大之臟). 2) The Theory of Eight Constitution was derived from the Theory of Eight morbidities, in which all kinds of human diseases are caused by 8 disease-orgin organ and that the diseases therefore can be classified into 8 morbidities. The Theory of Eight morbidities reorganized the Discourse on the Constitutional Symptoms and Diseases in "DongYiSuseBowon" by classifying them into first morbidity and second morbidity. 3) The Discourse on the Constitutional Symptoms and Diseases in "DongYiSuseBowon" has decisively affected the creation of the Theory of Eight morbidities which is the predecessor of the Theory of Eight Constitution. The Theory of Eight morbidities may be deemed another interpretation of the Discourse on the Constitutional Symptoms and Diseases in "DongYiSuseBowon". As the Theory of Eight morbidities put emphasis on the genetic characteristics, the Theory of Eight Constitution stating that Eight morbidities are caused by different specific constitution was derived.

Students' Knowledge, Acceptance of Theory of Evolution and Epistemology: Cross-sectional Study of Grade Level Differences

  • Kim, Sun Young
    • 과학교육연구지
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    • 제40권1호
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    • pp.1-16
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    • 2016
  • The purpose of this study is to explore the variables of knowledge, acceptance of theory of evolution and epistemology that could be keys for teaching and learning the theory of evolution within school contexts, and to suggest instructional tips for teaching evolution in relation to the grade levels of education. This cross-sectional study examined the grade level differences (8th, 11th, and preservice teachers) of four variables: evolutionary knowledge; acceptance of theory of evolution; and both domain-specific epistemology (nature of science in relation to evolution) and context-specific epistemology (scientific epistemological views) and their relationships. This study, then, built conceptual models of each grade level students' acceptance of theory of evolution among the factors of evolutionary knowledge and epistemology (both domain-specific and context-specific). The results showed that the scores of evolutionary knowledge, evolution in relation to NOS, and scientific epistemology increased as the grade levels of education go up(p<.05) except the scores of acceptance of theory of evolution(p>.05). In addition, the 8th graders' and the 11th graders' acceptance of evolutionary theory was most explained by 'evolution in relation to NOS', while the preservice teachers' acceptance of evolutionary theory was most explained by evolutionary knowledge. Interestingly, 'scientific epistemological views' were only included for the 8th graders, while evolutionary knowledge and 'evolution in relation to NOS' (context-specific epistemology) were included in explaining all the level of students' acceptance of evolutionary theory. This study implicated that when teaching and learning of the theory of evolution in school contexts, knowledge, acceptance of evolutionary theory and epistemology could be considered appropriately for the different grade levels of students.

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Two-temperature thermoelastic surface waves in micropolar thermoelastic media via dual-phase-lag model

  • Abouelregal, A.E.;Zenkour, A.M.
    • Advances in aircraft and spacecraft science
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    • 제4권6호
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    • pp.711-727
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    • 2017
  • This article is concerned with a two-dimensional problem of micropolar generalized thermoelasticity for a half-space whose surface is traction-free and the conductive temperature at the surface of the half-space is known. Theory of two-temperature generalized thermoelasticity with phase lags using the normal mode analysis is used to solve the present problem. The formulas of conductive and mechanical temperatures, displacement, micro-rotation, stresses and couple stresses are obtained. The considered quantities are illustrated graphically and their behaviors are discussed with suitable comparisons. The present results are compared with those obtained according to one temperature theory. It is concluded that both conductive heat wave and thermodynamical heat wave should be separated. The two-temperature theory describes the behavior of particles of elastic body more real than one-temperature theory.

{Ca,Sr,Ba}$Fe_2As_2$의 전자 및 자성 구조: 동력학적 평균장 이론 접근 (Electronic and Magnetic Structures of {Ca,Sr,Ba}$Fe_2As_2$ : Dynamical Mean Field Theory Approach)

  • 이근식;심지훈
    • Progress in Superconductivity
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    • 제13권2호
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    • pp.85-89
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    • 2011
  • 제일원리 DFT+DMFT방법을 사용하여 철계열 고온초전도체 122 화합물 $AFe_2As_2$ (A=Ca, Sr, Ba) 에 대한 전자 및 자성 구조를 계산하였다. 계산된 전자구조는 실험에서 보고된 ARPES 결과와 어느 정도 일치함을 확인했다. 또한 계산을 통해 얻은 반자성 전이온도는 실험과 동일한 경향을 보여준다.

LIMIT RELATIVE CATEGORY THEORY APPLIED TO THE CRITICAL POINT THEORY

  • Jung, Tack-Sun;Choi, Q-Heung
    • 대한수학회보
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    • 제46권2호
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    • pp.311-319
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    • 2009
  • Let H be a Hilbert space which is the direct sum of five closed subspaces $X_0,\;X_1,\;X_2,\;X_3$ and $X_4$ with $X_1,\;X_2,\;X_3$ of finite dimension. Let J be a $C^{1,1}$ functional defined on H with J(0) = 0. We show the existence of at least four nontrivial critical points when the sublevels of J (the torus with three holes and sphere) link and the functional J satisfies sup-inf variational inequality on the linking subspaces, and the functional J satisfies $(P.S.)^*_c$ condition and $f|X_0{\otimes}X_4$ has no critical point with level c. For the proof of main theorem we use the nonsmooth version of the classical deformation lemma and the limit relative category theory.

A four-variable plate theory for thermal vibration of embedded FG nanoplates under non-uniform temperature distributions with different boundary conditions

  • Barati, Mohammad Reza;Shahverdi, Hossein
    • Structural Engineering and Mechanics
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    • 제60권4호
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    • pp.707-727
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    • 2016
  • In this paper, thermal vibration of a nonlocal functionally graded (FG) plates with arbitrary boundary conditions under linear and non-linear temperature fields is explored by developing a refined shear deformation plate theory with an inverse cotangential function in which shear deformation effect was involved without the need for shear correction factors. The material properties of FG nanoplate are considered to be temperature-dependent and graded in the thickness direction according to the Mori-Tanaka model. On the basis of non-classical higher order plate model and Eringen's nonlocal elasticity theory, the small size influence was captured. Numerical examples show the importance of non-uniform thermal loadings, boundary conditions, gradient index, nonlocal parameter and aspect and side-to-thickness ratio on vibrational responses of size-dependent FG nanoplates.